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+This is dash.info, produced by makeinfo version 6.7 from dash.texi.
+
+This manual is for Dash version 2.19.1.
+
+ Copyright © 2012–2021 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this
+ document under the terms of the GNU Free Documentation License,
+ Version 1.3 or any later version published by the Free Software
+ Foundation; with the Invariant Sections being “GNU General Public
+ License,” and no Front-Cover Texts or Back-Cover Texts. A copy of
+ the license is included in the section entitled “GNU Free
+ Documentation License”.
+INFO-DIR-SECTION Emacs
+START-INFO-DIR-ENTRY
+* Dash: (dash.info). A modern list library for GNU Emacs.
+END-INFO-DIR-ENTRY
+
+
+File: dash.info, Node: Top, Next: Installation, Up: (dir)
+
+Dash
+****
+
+This manual is for Dash version 2.19.1.
+
+ Copyright © 2012–2021 Free Software Foundation, Inc.
+
+ Permission is granted to copy, distribute and/or modify this
+ document under the terms of the GNU Free Documentation License,
+ Version 1.3 or any later version published by the Free Software
+ Foundation; with the Invariant Sections being “GNU General Public
+ License,” and no Front-Cover Texts or Back-Cover Texts. A copy of
+ the license is included in the section entitled “GNU Free
+ Documentation License”.
+
+* Menu:
+
+* Installation:: Installing and configuring Dash.
+* Functions:: Dash API reference.
+* Development:: Contributing to Dash development.
+
+Appendices
+
+* FDL:: The license for this documentation.
+* GPL:: Conditions for copying and changing Dash.
+* Index:: Index including functions and macros.
+
+ — The Detailed Node Listing —
+
+Installation
+
+* Using in a package:: Listing Dash as a package dependency.
+* Fontification of special variables:: Font Lock of anaphoric macro variables.
+* Info symbol lookup:: Looking up Dash symbols in this manual.
+
+Functions
+
+* Maps::
+* Sublist selection::
+* List to list::
+* Reductions::
+* Unfolding::
+* Predicates::
+* Partitioning::
+* Indexing::
+* Set operations::
+* Other list operations::
+* Tree operations::
+* Threading macros::
+* Binding::
+* Side effects::
+* Destructive operations::
+* Function combinators::
+
+Development
+
+* Contribute:: How to contribute.
+* Contributors:: List of contributors.
+
+
+File: dash.info, Node: Installation, Next: Functions, Prev: Top, Up: Top
+
+1 Installation
+**************
+
+Dash is available on GNU ELPA (https://elpa.gnu.org/), GNU-devel ELPA
+(https://elpa.gnu.org/devel/), and MELPA (https://melpa.org/), and can
+be installed with the standard command ‘package-install’ (*note
+(emacs)Package Installation::).
+
+‘M-x package-install <RET> dash <RET>’
+ Install the Dash library.
+
+ Alternatively, you can just dump ‘dash.el’ in your ‘load-path’
+somewhere (*note (emacs)Lisp Libraries::).
+
+* Menu:
+
+* Using in a package:: Listing Dash as a package dependency.
+* Fontification of special variables:: Font Lock of anaphoric macro variables.
+* Info symbol lookup:: Looking up Dash symbols in this manual.
+
+
+File: dash.info, Node: Using in a package, Next: Fontification of special variables, Up: Installation
+
+1.1 Using in a package
+======================
+
+If you use Dash in your own package, be sure to list it as a dependency
+in the library’s headers as follows (*note (elisp)Library Headers::).
+
+ ;; Package-Requires: ((dash "2.19.1"))
+
+
+File: dash.info, Node: Fontification of special variables, Next: Info symbol lookup, Prev: Using in a package, Up: Installation
+
+1.2 Fontification of special variables
+======================================
+
+The autoloaded minor mode ‘dash-fontify-mode’ is provided for optional
+fontification of anaphoric Dash variables (‘it’, ‘acc’, etc.) in Emacs
+Lisp buffers using search-based Font Lock (*note (emacs)Font Lock::).
+In older Emacs versions which do not dynamically detect macros, the
+minor mode also fontifies calls to Dash macros.
+
+ To automatically enable the minor mode in all Emacs Lisp buffers,
+just call its autoloaded global counterpart ‘global-dash-fontify-mode’,
+either interactively or from your ‘user-init-file’:
+
+ (global-dash-fontify-mode)
+
+
+File: dash.info, Node: Info symbol lookup, Prev: Fontification of special variables, Up: Installation
+
+1.3 Info symbol lookup
+======================
+
+While editing Elisp files, you can use ‘C-h S’ (‘info-lookup-symbol’) to
+look up Elisp symbols in the relevant Info manuals (*note (emacs)Info
+Lookup::). To enable the same for Dash symbols, use the command
+‘dash-register-info-lookup’. It can be called directly when needed, or
+automatically from your ‘user-init-file’. For example:
+
+ (with-eval-after-load 'info-look
+ (dash-register-info-lookup))
+
+
+File: dash.info, Node: Functions, Next: Development, Prev: Installation, Up: Top
+
+2 Functions
+***********
+
+This chapter contains reference documentation for the Dash API
+(Application Programming Interface). The names of all public functions
+defined in the library are prefixed with a dash character (‘-’).
+
+ The library also provides anaphoric macro versions of functions where
+that makes sense. The names of these macros are prefixed with two
+dashes (‘--’) instead of one.
+
+ For instance, while the function ‘-map’ applies a function to each
+element of a list, its anaphoric counterpart ‘--map’ evaluates a form
+with the local variable ‘it’ temporarily bound to the current list
+element instead.
+
+ ;; Normal version.
+ (-map (lambda (n) (* n n)) '(1 2 3 4))
+ ⇒ (1 4 9 16)
+
+ ;; Anaphoric version.
+ (--map (* it it) '(1 2 3 4))
+ ⇒ (1 4 9 16)
+
+ The normal version can, of course, also be written as in the
+following example, which demonstrates the utility of both versions.
+
+ (defun my-square (n)
+ "Return N multiplied by itself."
+ (* n n))
+
+ (-map #'my-square '(1 2 3 4))
+ ⇒ (1 4 9 16)
+
+* Menu:
+
+* Maps::
+* Sublist selection::
+* List to list::
+* Reductions::
+* Unfolding::
+* Predicates::
+* Partitioning::
+* Indexing::
+* Set operations::
+* Other list operations::
+* Tree operations::
+* Threading macros::
+* Binding::
+* Side effects::
+* Destructive operations::
+* Function combinators::
+
+
+File: dash.info, Node: Maps, Next: Sublist selection, Up: Functions
+
+2.1 Maps
+========
+
+Functions in this category take a transforming function, which is then
+applied sequentially to each or selected elements of the input list.
+The results are collected in order and returned as a new list.
+
+ -- Function: -map (fn list)
+ Apply FN to each item in LIST and return the list of results.
+
+ This function’s anaphoric counterpart is ‘--map’.
+
+ (-map (lambda (num) (* num num)) '(1 2 3 4))
+ ⇒ (1 4 9 16)
+ (-map #'1+ '(1 2 3 4))
+ ⇒ (2 3 4 5)
+ (--map (* it it) '(1 2 3 4))
+ ⇒ (1 4 9 16)
+
+ -- Function: -map-when (pred rep list)
+ Use PRED to conditionally apply REP to each item in LIST. Return a
+ copy of LIST where the items for which PRED returns ‘nil’ are
+ unchanged, and the rest are mapped through the REP function.
+
+ Alias: ‘-replace-where’
+
+ See also: ‘-update-at’ (*note -update-at::)
+
+ (-map-when 'even? 'square '(1 2 3 4))
+ ⇒ (1 4 3 16)
+ (--map-when (> it 2) (* it it) '(1 2 3 4))
+ ⇒ (1 2 9 16)
+ (--map-when (= it 2) 17 '(1 2 3 4))
+ ⇒ (1 17 3 4)
+
+ -- Function: -map-first (pred rep list)
+ Use PRED to determine the first item in LIST to call REP on.
+ Return a copy of LIST where the first item for which PRED returns
+ non-‘nil’ is replaced with the result of calling REP on that item.
+
+ See also: ‘-map-when’ (*note -map-when::), ‘-replace-first’ (*note
+ -replace-first::)
+
+ (-map-first 'even? 'square '(1 2 3 4))
+ ⇒ (1 4 3 4)
+ (--map-first (> it 2) (* it it) '(1 2 3 4))
+ ⇒ (1 2 9 4)
+ (--map-first (= it 2) 17 '(1 2 3 2))
+ ⇒ (1 17 3 2)
+
+ -- Function: -map-last (pred rep list)
+ Use PRED to determine the last item in LIST to call REP on. Return
+ a copy of LIST where the last item for which PRED returns non-‘nil’
+ is replaced with the result of calling REP on that item.
+
+ See also: ‘-map-when’ (*note -map-when::), ‘-replace-last’ (*note
+ -replace-last::)
+
+ (-map-last 'even? 'square '(1 2 3 4))
+ ⇒ (1 2 3 16)
+ (--map-last (> it 2) (* it it) '(1 2 3 4))
+ ⇒ (1 2 3 16)
+ (--map-last (= it 2) 17 '(1 2 3 2))
+ ⇒ (1 2 3 17)
+
+ -- Function: -map-indexed (fn list)
+ Apply FN to each index and item in LIST and return the list of
+ results. This is like ‘-map’ (*note -map::), but FN takes two
+ arguments: the index of the current element within LIST, and the
+ element itself.
+
+ This function’s anaphoric counterpart is ‘--map-indexed’.
+
+ For a side-effecting variant, see also ‘-each-indexed’ (*note
+ -each-indexed::).
+
+ (-map-indexed (lambda (index item) (- item index)) '(1 2 3 4))
+ ⇒ (1 1 1 1)
+ (--map-indexed (- it it-index) '(1 2 3 4))
+ ⇒ (1 1 1 1)
+ (-map-indexed #'* '(1 2 3 4))
+ ⇒ (0 2 6 12)
+
+ -- Function: -annotate (fn list)
+ Return a list of cons cells where each cell is FN applied to each
+ element of LIST paired with the unmodified element of LIST.
+
+ (-annotate '1+ '(1 2 3))
+ ⇒ ((2 . 1) (3 . 2) (4 . 3))
+ (-annotate 'length '(("h" "e" "l" "l" "o") ("hello" "world")))
+ ⇒ ((5 "h" "e" "l" "l" "o") (2 "hello" "world"))
+ (--annotate (< 1 it) '(0 1 2 3))
+ ⇒ ((nil . 0) (nil . 1) (t . 2) (t . 3))
+
+ -- Function: -splice (pred fun list)
+ Splice lists generated by FUN in place of elements matching PRED in
+ LIST.
+
+ FUN takes the element matching PRED as input.
+
+ This function can be used as replacement for ‘,@’ in case you need
+ to splice several lists at marked positions (for example with
+ keywords).
+
+ See also: ‘-splice-list’ (*note -splice-list::), ‘-insert-at’
+ (*note -insert-at::)
+
+ (-splice 'even? (lambda (x) (list x x)) '(1 2 3 4))
+ ⇒ (1 2 2 3 4 4)
+ (--splice 't (list it it) '(1 2 3 4))
+ ⇒ (1 1 2 2 3 3 4 4)
+ (--splice (equal it :magic) '((list of) (magical) (code)) '((foo) (bar) :magic (baz)))
+ ⇒ ((foo) (bar) (list of) (magical) (code) (baz))
+
+ -- Function: -splice-list (pred new-list list)
+ Splice NEW-LIST in place of elements matching PRED in LIST.
+
+ See also: ‘-splice’ (*note -splice::), ‘-insert-at’ (*note
+ -insert-at::)
+
+ (-splice-list 'keywordp '(a b c) '(1 :foo 2))
+ ⇒ (1 a b c 2)
+ (-splice-list 'keywordp nil '(1 :foo 2))
+ ⇒ (1 2)
+ (--splice-list (keywordp it) '(a b c) '(1 :foo 2))
+ ⇒ (1 a b c 2)
+
+ -- Function: -mapcat (fn list)
+ Return the concatenation of the result of mapping FN over LIST.
+ Thus function FN should return a list.
+
+ (-mapcat 'list '(1 2 3))
+ ⇒ (1 2 3)
+ (-mapcat (lambda (item) (list 0 item)) '(1 2 3))
+ ⇒ (0 1 0 2 0 3)
+ (--mapcat (list 0 it) '(1 2 3))
+ ⇒ (0 1 0 2 0 3)
+
+ -- Function: -copy (list)
+ Create a shallow copy of LIST.
+
+ (-copy '(1 2 3))
+ ⇒ (1 2 3)
+ (let ((a '(1 2 3))) (eq a (-copy a)))
+ ⇒ nil
+
+
+File: dash.info, Node: Sublist selection, Next: List to list, Prev: Maps, Up: Functions
+
+2.2 Sublist selection
+=====================
+
+Functions returning a sublist of the original list.
+
+ -- Function: -filter (pred list)
+ Return a new list of the items in LIST for which PRED returns
+ non-‘nil’.
+
+ Alias: ‘-select’.
+
+ This function’s anaphoric counterpart is ‘--filter’.
+
+ For similar operations, see also ‘-keep’ (*note -keep::) and
+ ‘-remove’ (*note -remove::).
+
+ (-filter (lambda (num) (= 0 (% num 2))) '(1 2 3 4))
+ ⇒ (2 4)
+ (-filter #'natnump '(-2 -1 0 1 2))
+ ⇒ (0 1 2)
+ (--filter (= 0 (% it 2)) '(1 2 3 4))
+ ⇒ (2 4)
+
+ -- Function: -remove (pred list)
+ Return a new list of the items in LIST for which PRED returns
+ ‘nil’.
+
+ Alias: ‘-reject’.
+
+ This function’s anaphoric counterpart is ‘--remove’.
+
+ For similar operations, see also ‘-keep’ (*note -keep::) and
+ ‘-filter’ (*note -filter::).
+
+ (-remove (lambda (num) (= 0 (% num 2))) '(1 2 3 4))
+ ⇒ (1 3)
+ (-remove #'natnump '(-2 -1 0 1 2))
+ ⇒ (-2 -1)
+ (--remove (= 0 (% it 2)) '(1 2 3 4))
+ ⇒ (1 3)
+
+ -- Function: -remove-first (pred list)
+ Remove the first item from LIST for which PRED returns non-‘nil’.
+ This is a non-destructive operation, but only the front of LIST
+ leading up to the removed item is a copy; the rest is LIST’s
+ original tail. If no item is removed, then the result is a
+ complete copy.
+
+ Alias: ‘-reject-first’.
+
+ This function’s anaphoric counterpart is ‘--remove-first’.
+
+ See also ‘-map-first’ (*note -map-first::), ‘-remove-item’ (*note
+ -remove-item::), and ‘-remove-last’ (*note -remove-last::).
+
+ (-remove-first #'natnump '(-2 -1 0 1 2))
+ ⇒ (-2 -1 1 2)
+ (-remove-first #'stringp '(1 2 "first" "second"))
+ ⇒ (1 2 "second")
+ (--remove-first (> it 3) '(1 2 3 4 5 6))
+ ⇒ (1 2 3 5 6)
+
+ -- Function: -remove-last (pred list)
+ Remove the last item from LIST for which PRED returns non-‘nil’.
+ The result is a copy of LIST regardless of whether an element is
+ removed.
+
+ Alias: ‘-reject-last’.
+
+ This function’s anaphoric counterpart is ‘--remove-last’.
+
+ See also ‘-map-last’ (*note -map-last::), ‘-remove-item’ (*note
+ -remove-item::), and ‘-remove-first’ (*note -remove-first::).
+
+ (-remove-last #'natnump '(1 3 5 4 7 8 10 -11))
+ ⇒ (1 3 5 4 7 8 -11)
+ (-remove-last #'stringp '(1 2 "last" "second"))
+ ⇒ (1 2 "last")
+ (--remove-last (> it 3) '(1 2 3 4 5 6 7 8 9 10))
+ ⇒ (1 2 3 4 5 6 7 8 9)
+
+ -- Function: -remove-item (item list)
+ Return a copy of LIST with all occurrences of ITEM removed. The
+ comparison is done with ‘equal’.
+
+ (-remove-item 3 '(1 2 3 2 3 4 5 3))
+ ⇒ (1 2 2 4 5)
+ (-remove-item 'foo '(foo bar baz foo))
+ ⇒ (bar baz)
+ (-remove-item "bob" '("alice" "bob" "eve" "bob"))
+ ⇒ ("alice" "eve")
+
+ -- Function: -non-nil (list)
+ Return a copy of LIST with all ‘nil’ items removed.
+
+ (-non-nil '(nil 1 nil 2 nil nil 3 4 nil 5 nil))
+ ⇒ (1 2 3 4 5)
+ (-non-nil '((nil)))
+ ⇒ ((nil))
+ (-non-nil ())
+ ⇒ ()
+
+ -- Function: -slice (list from &optional to step)
+ Return copy of LIST, starting from index FROM to index TO.
+
+ FROM or TO may be negative. These values are then interpreted
+ modulo the length of the list.
+
+ If STEP is a number, only each STEPth item in the resulting section
+ is returned. Defaults to 1.
+
+ (-slice '(1 2 3 4 5) 1)
+ ⇒ (2 3 4 5)
+ (-slice '(1 2 3 4 5) 0 3)
+ ⇒ (1 2 3)
+ (-slice '(1 2 3 4 5 6 7 8 9) 1 -1 2)
+ ⇒ (2 4 6 8)
+
+ -- Function: -take (n list)
+ Return a copy of the first N items in LIST. Return a copy of LIST
+ if it contains N items or fewer. Return ‘nil’ if N is zero or
+ less.
+
+ See also: ‘-take-last’ (*note -take-last::).
+
+ (-take 3 '(1 2 3 4 5))
+ ⇒ (1 2 3)
+ (-take 17 '(1 2 3 4 5))
+ ⇒ (1 2 3 4 5)
+ (-take 0 '(1 2 3 4 5))
+ ⇒ ()
+
+ -- Function: -take-last (n list)
+ Return a copy of the last N items of LIST in order. Return a copy
+ of LIST if it contains N items or fewer. Return ‘nil’ if N is zero
+ or less.
+
+ See also: ‘-take’ (*note -take::).
+
+ (-take-last 3 '(1 2 3 4 5))
+ ⇒ (3 4 5)
+ (-take-last 17 '(1 2 3 4 5))
+ ⇒ (1 2 3 4 5)
+ (-take-last 1 '(1 2 3 4 5))
+ ⇒ (5)
+
+ -- Function: -drop (n list)
+ Return the tail (not a copy) of LIST without the first N items.
+ Return ‘nil’ if LIST contains N items or fewer. Return LIST if N
+ is zero or less.
+
+ For another variant, see also ‘-drop-last’ (*note -drop-last::).
+
+ (-drop 3 '(1 2 3 4 5))
+ ⇒ (4 5)
+ (-drop 17 '(1 2 3 4 5))
+ ⇒ ()
+ (-drop 0 '(1 2 3 4 5))
+ ⇒ (1 2 3 4 5)
+
+ -- Function: -drop-last (n list)
+ Return a copy of LIST without its last N items. Return a copy of
+ LIST if N is zero or less. Return ‘nil’ if LIST contains N items
+ or fewer.
+
+ See also: ‘-drop’ (*note -drop::).
+
+ (-drop-last 3 '(1 2 3 4 5))
+ ⇒ (1 2)
+ (-drop-last 17 '(1 2 3 4 5))
+ ⇒ ()
+ (-drop-last 0 '(1 2 3 4 5))
+ ⇒ (1 2 3 4 5)
+
+ -- Function: -take-while (pred list)
+ Take successive items from LIST for which PRED returns non-‘nil’.
+ PRED is a function of one argument. Return a new list of the
+ successive elements from the start of LIST for which PRED returns
+ non-‘nil’.
+
+ This function’s anaphoric counterpart is ‘--take-while’.
+
+ For another variant, see also ‘-drop-while’ (*note -drop-while::).
+
+ (-take-while #'even? '(1 2 3 4))
+ ⇒ ()
+ (-take-while #'even? '(2 4 5 6))
+ ⇒ (2 4)
+ (--take-while (< it 4) '(1 2 3 4 3 2 1))
+ ⇒ (1 2 3)
+
+ -- Function: -drop-while (pred list)
+ Drop successive items from LIST for which PRED returns non-‘nil’.
+ PRED is a function of one argument. Return the tail (not a copy)
+ of LIST starting from its first element for which PRED returns
+ ‘nil’.
+
+ This function’s anaphoric counterpart is ‘--drop-while’.
+
+ For another variant, see also ‘-take-while’ (*note -take-while::).
+
+ (-drop-while #'even? '(1 2 3 4))
+ ⇒ (1 2 3 4)
+ (-drop-while #'even? '(2 4 5 6))
+ ⇒ (5 6)
+ (--drop-while (< it 4) '(1 2 3 4 3 2 1))
+ ⇒ (4 3 2 1)
+
+ -- Function: -select-by-indices (indices list)
+ Return a list whose elements are elements from LIST selected as
+ ‘(nth i list)‘ for all i from INDICES.
+
+ (-select-by-indices '(4 10 2 3 6) '("v" "e" "l" "o" "c" "i" "r" "a" "p" "t" "o" "r"))
+ ⇒ ("c" "o" "l" "o" "r")
+ (-select-by-indices '(2 1 0) '("a" "b" "c"))
+ ⇒ ("c" "b" "a")
+ (-select-by-indices '(0 1 2 0 1 3 3 1) '("f" "a" "r" "l"))
+ ⇒ ("f" "a" "r" "f" "a" "l" "l" "a")
+
+ -- Function: -select-columns (columns table)
+ Select COLUMNS from TABLE.
+
+ TABLE is a list of lists where each element represents one row. It
+ is assumed each row has the same length.
+
+ Each row is transformed such that only the specified COLUMNS are
+ selected.
+
+ See also: ‘-select-column’ (*note -select-column::),
+ ‘-select-by-indices’ (*note -select-by-indices::)
+
+ (-select-columns '(0 2) '((1 2 3) (a b c) (:a :b :c)))
+ ⇒ ((1 3) (a c) (:a :c))
+ (-select-columns '(1) '((1 2 3) (a b c) (:a :b :c)))
+ ⇒ ((2) (b) (:b))
+ (-select-columns nil '((1 2 3) (a b c) (:a :b :c)))
+ ⇒ (nil nil nil)
+
+ -- Function: -select-column (column table)
+ Select COLUMN from TABLE.
+
+ TABLE is a list of lists where each element represents one row. It
+ is assumed each row has the same length.
+
+ The single selected column is returned as a list.
+
+ See also: ‘-select-columns’ (*note -select-columns::),
+ ‘-select-by-indices’ (*note -select-by-indices::)
+
+ (-select-column 1 '((1 2 3) (a b c) (:a :b :c)))
+ ⇒ (2 b :b)
+
+
+File: dash.info, Node: List to list, Next: Reductions, Prev: Sublist selection, Up: Functions
+
+2.3 List to list
+================
+
+Functions returning a modified copy of the input list.
+
+ -- Function: -keep (fn list)
+ Return a new list of the non-‘nil’ results of applying FN to each
+ item in LIST. Like ‘-filter’ (*note -filter::), but returns the
+ non-‘nil’ results of FN instead of the corresponding elements of
+ LIST.
+
+ Its anaphoric counterpart is ‘--keep’.
+
+ (-keep #'cdr '((1 2 3) (4 5) (6)))
+ ⇒ ((2 3) (5))
+ (-keep (lambda (n) (and (> n 3) (* 10 n))) '(1 2 3 4 5 6))
+ ⇒ (40 50 60)
+ (--keep (and (> it 3) (* 10 it)) '(1 2 3 4 5 6))
+ ⇒ (40 50 60)
+
+ -- Function: -concat (&rest sequences)
+ Concatenate all the arguments and make the result a list. The
+ result is a list whose elements are the elements of all the
+ arguments. Each argument may be a list, vector or string. The
+ last argument is not copied, just used as the tail of the new list.
+
+ (-concat '(1))
+ ⇒ (1)
+ (-concat '(1) '(2))
+ ⇒ (1 2)
+ (-concat '(1) '(2 3) '(4))
+ ⇒ (1 2 3 4)
+
+ -- Function: -flatten (l)
+ Take a nested list L and return its contents as a single, flat
+ list.
+
+ Note that because ‘nil’ represents a list of zero elements (an
+ empty list), any mention of ‘nil’ in L will disappear after
+ flattening. If you need to preserve nils, consider ‘-flatten-n’
+ (*note -flatten-n::) or map them to some unique symbol and then map
+ them back.
+
+ Conses of two atoms are considered "terminals", that is, they
+ aren’t flattened further.
+
+ See also: ‘-flatten-n’ (*note -flatten-n::)
+
+ (-flatten '((1)))
+ ⇒ (1)
+ (-flatten '((1 (2 3) (((4 (5)))))))
+ ⇒ (1 2 3 4 5)
+ (-flatten '(1 2 (3 . 4)))
+ ⇒ (1 2 (3 . 4))
+
+ -- Function: -flatten-n (num list)
+ Flatten NUM levels of a nested LIST.
+
+ See also: ‘-flatten’ (*note -flatten::)
+
+ (-flatten-n 1 '((1 2) ((3 4) ((5 6)))))
+ ⇒ (1 2 (3 4) ((5 6)))
+ (-flatten-n 2 '((1 2) ((3 4) ((5 6)))))
+ ⇒ (1 2 3 4 (5 6))
+ (-flatten-n 3 '((1 2) ((3 4) ((5 6)))))
+ ⇒ (1 2 3 4 5 6)
+
+ -- Function: -replace (old new list)
+ Replace all OLD items in LIST with NEW.
+
+ Elements are compared using ‘equal’.
+
+ See also: ‘-replace-at’ (*note -replace-at::)
+
+ (-replace 1 "1" '(1 2 3 4 3 2 1))
+ ⇒ ("1" 2 3 4 3 2 "1")
+ (-replace "foo" "bar" '("a" "nice" "foo" "sentence" "about" "foo"))
+ ⇒ ("a" "nice" "bar" "sentence" "about" "bar")
+ (-replace 1 2 nil)
+ ⇒ nil
+
+ -- Function: -replace-first (old new list)
+ Replace the first occurrence of OLD with NEW in LIST.
+
+ Elements are compared using ‘equal’.
+
+ See also: ‘-map-first’ (*note -map-first::)
+
+ (-replace-first 1 "1" '(1 2 3 4 3 2 1))
+ ⇒ ("1" 2 3 4 3 2 1)
+ (-replace-first "foo" "bar" '("a" "nice" "foo" "sentence" "about" "foo"))
+ ⇒ ("a" "nice" "bar" "sentence" "about" "foo")
+ (-replace-first 1 2 nil)
+ ⇒ nil
+
+ -- Function: -replace-last (old new list)
+ Replace the last occurrence of OLD with NEW in LIST.
+
+ Elements are compared using ‘equal’.
+
+ See also: ‘-map-last’ (*note -map-last::)
+
+ (-replace-last 1 "1" '(1 2 3 4 3 2 1))
+ ⇒ (1 2 3 4 3 2 "1")
+ (-replace-last "foo" "bar" '("a" "nice" "foo" "sentence" "about" "foo"))
+ ⇒ ("a" "nice" "foo" "sentence" "about" "bar")
+ (-replace-last 1 2 nil)
+ ⇒ nil
+
+ -- Function: -insert-at (n x list)
+ Return a list with X inserted into LIST at position N.
+
+ See also: ‘-splice’ (*note -splice::), ‘-splice-list’ (*note
+ -splice-list::)
+
+ (-insert-at 1 'x '(a b c))
+ ⇒ (a x b c)
+ (-insert-at 12 'x '(a b c))
+ ⇒ (a b c x)
+
+ -- Function: -replace-at (n x list)
+ Return a list with element at Nth position in LIST replaced with X.
+
+ See also: ‘-replace’ (*note -replace::)
+
+ (-replace-at 0 9 '(0 1 2 3 4 5))
+ ⇒ (9 1 2 3 4 5)
+ (-replace-at 1 9 '(0 1 2 3 4 5))
+ ⇒ (0 9 2 3 4 5)
+ (-replace-at 4 9 '(0 1 2 3 4 5))
+ ⇒ (0 1 2 3 9 5)
+
+ -- Function: -update-at (n func list)
+ Use FUNC to update the Nth element of LIST. Return a copy of LIST
+ where the Nth element is replaced with the result of calling FUNC
+ on it.
+
+ See also: ‘-map-when’ (*note -map-when::)
+
+ (-update-at 0 (lambda (x) (+ x 9)) '(0 1 2 3 4 5))
+ ⇒ (9 1 2 3 4 5)
+ (-update-at 1 (lambda (x) (+ x 8)) '(0 1 2 3 4 5))
+ ⇒ (0 9 2 3 4 5)
+ (--update-at 2 (length it) '("foo" "bar" "baz" "quux"))
+ ⇒ ("foo" "bar" 3 "quux")
+
+ -- Function: -remove-at (n list)
+ Return a list with element at Nth position in LIST removed.
+
+ See also: ‘-remove-at-indices’ (*note -remove-at-indices::),
+ ‘-remove’ (*note -remove::)
+
+ (-remove-at 0 '("0" "1" "2" "3" "4" "5"))
+ ⇒ ("1" "2" "3" "4" "5")
+ (-remove-at 1 '("0" "1" "2" "3" "4" "5"))
+ ⇒ ("0" "2" "3" "4" "5")
+ (-remove-at 2 '("0" "1" "2" "3" "4" "5"))
+ ⇒ ("0" "1" "3" "4" "5")
+
+ -- Function: -remove-at-indices (indices list)
+ Return a list whose elements are elements from LIST without
+ elements selected as ‘(nth i list)‘ for all i from INDICES.
+
+ See also: ‘-remove-at’ (*note -remove-at::), ‘-remove’ (*note
+ -remove::)
+
+ (-remove-at-indices '(0) '("0" "1" "2" "3" "4" "5"))
+ ⇒ ("1" "2" "3" "4" "5")
+ (-remove-at-indices '(0 2 4) '("0" "1" "2" "3" "4" "5"))
+ ⇒ ("1" "3" "5")
+ (-remove-at-indices '(0 5) '("0" "1" "2" "3" "4" "5"))
+ ⇒ ("1" "2" "3" "4")
+
+
+File: dash.info, Node: Reductions, Next: Unfolding, Prev: List to list, Up: Functions
+
+2.4 Reductions
+==============
+
+Functions reducing lists to a single value (which may also be a list).
+
+ -- Function: -reduce-from (fn init list)
+ Reduce the function FN across LIST, starting with INIT. Return the
+ result of applying FN to INIT and the first element of LIST, then
+ applying FN to that result and the second element, etc. If LIST is
+ empty, return INIT without calling FN.
+
+ This function’s anaphoric counterpart is ‘--reduce-from’.
+
+ For other folds, see also ‘-reduce’ (*note -reduce::) and
+ ‘-reduce-r’ (*note -reduce-r::).
+
+ (-reduce-from #'- 10 '(1 2 3))
+ ⇒ 4
+ (-reduce-from #'list 10 '(1 2 3))
+ ⇒ (((10 1) 2) 3)
+ (--reduce-from (concat acc " " it) "START" '("a" "b" "c"))
+ ⇒ "START a b c"
+
+ -- Function: -reduce-r-from (fn init list)
+ Reduce the function FN across LIST in reverse, starting with INIT.
+ Return the result of applying FN to the last element of LIST and
+ INIT, then applying FN to the second-to-last element and the
+ previous result of FN, etc. That is, the first argument of FN is
+ the current element, and its second argument the accumulated value.
+ If LIST is empty, return INIT without calling FN.
+
+ This function is like ‘-reduce-from’ (*note -reduce-from::) but the
+ operation associates from the right rather than left. In other
+ words, it starts from the end of LIST and flips the arguments to
+ FN. Conceptually, it is like replacing the conses in LIST with
+ applications of FN, and its last link with INIT, and evaluating the
+ resulting expression.
+
+ This function’s anaphoric counterpart is ‘--reduce-r-from’.
+
+ For other folds, see also ‘-reduce-r’ (*note -reduce-r::) and
+ ‘-reduce’ (*note -reduce::).
+
+ (-reduce-r-from #'- 10 '(1 2 3))
+ ⇒ -8
+ (-reduce-r-from #'list 10 '(1 2 3))
+ ⇒ (1 (2 (3 10)))
+ (--reduce-r-from (concat it " " acc) "END" '("a" "b" "c"))
+ ⇒ "a b c END"
+
+ -- Function: -reduce (fn list)
+ Reduce the function FN across LIST. Return the result of applying
+ FN to the first two elements of LIST, then applying FN to that
+ result and the third element, etc. If LIST contains a single
+ element, return it without calling FN. If LIST is empty, return
+ the result of calling FN with no arguments.
+
+ This function’s anaphoric counterpart is ‘--reduce’.
+
+ For other folds, see also ‘-reduce-from’ (*note -reduce-from::) and
+ ‘-reduce-r’ (*note -reduce-r::).
+
+ (-reduce #'- '(1 2 3 4))
+ ⇒ -8
+ (-reduce #'list '(1 2 3 4))
+ ⇒ (((1 2) 3) 4)
+ (--reduce (format "%s-%d" acc it) '(1 2 3))
+ ⇒ "1-2-3"
+
+ -- Function: -reduce-r (fn list)
+ Reduce the function FN across LIST in reverse. Return the result
+ of applying FN to the last two elements of LIST, then applying FN
+ to the third-to-last element and the previous result of FN, etc.
+ That is, the first argument of FN is the current element, and its
+ second argument the accumulated value. If LIST contains a single
+ element, return it without calling FN. If LIST is empty, return
+ the result of calling FN with no arguments.
+
+ This function is like ‘-reduce’ (*note -reduce::) but the operation
+ associates from the right rather than left. In other words, it
+ starts from the end of LIST and flips the arguments to FN.
+ Conceptually, it is like replacing the conses in LIST with
+ applications of FN, ignoring its last link, and evaluating the
+ resulting expression.
+
+ This function’s anaphoric counterpart is ‘--reduce-r’.
+
+ For other folds, see also ‘-reduce-r-from’ (*note -reduce-r-from::)
+ and ‘-reduce’ (*note -reduce::).
+
+ (-reduce-r #'- '(1 2 3 4))
+ ⇒ -2
+ (-reduce-r #'list '(1 2 3 4))
+ ⇒ (1 (2 (3 4)))
+ (--reduce-r (format "%s-%d" acc it) '(1 2 3))
+ ⇒ "3-2-1"
+
+ -- Function: -reductions-from (fn init list)
+ Return a list of FN’s intermediate reductions across LIST. That
+ is, a list of the intermediate values of the accumulator when
+ ‘-reduce-from’ (*note -reduce-from::) (which see) is called with
+ the same arguments.
+
+ This function’s anaphoric counterpart is ‘--reductions-from’.
+
+ For other folds, see also ‘-reductions’ (*note -reductions::) and
+ ‘-reductions-r’ (*note -reductions-r::).
+
+ (-reductions-from #'max 0 '(2 1 4 3))
+ ⇒ (0 2 2 4 4)
+ (-reductions-from #'* 1 '(1 2 3 4))
+ ⇒ (1 1 2 6 24)
+ (--reductions-from (format "(FN %s %d)" acc it) "INIT" '(1 2 3))
+ ⇒ ("INIT" "(FN INIT 1)" "(FN (FN INIT 1) 2)" "(FN (FN (FN INIT 1) 2) 3)")
+
+ -- Function: -reductions-r-from (fn init list)
+ Return a list of FN’s intermediate reductions across reversed LIST.
+ That is, a list of the intermediate values of the accumulator when
+ ‘-reduce-r-from’ (*note -reduce-r-from::) (which see) is called
+ with the same arguments.
+
+ This function’s anaphoric counterpart is ‘--reductions-r-from’.
+
+ For other folds, see also ‘-reductions’ (*note -reductions::) and
+ ‘-reductions-r’ (*note -reductions-r::).
+
+ (-reductions-r-from #'max 0 '(2 1 4 3))
+ ⇒ (4 4 4 3 0)
+ (-reductions-r-from #'* 1 '(1 2 3 4))
+ ⇒ (24 24 12 4 1)
+ (--reductions-r-from (format "(FN %d %s)" it acc) "INIT" '(1 2 3))
+ ⇒ ("(FN 1 (FN 2 (FN 3 INIT)))" "(FN 2 (FN 3 INIT))" "(FN 3 INIT)" "INIT")
+
+ -- Function: -reductions (fn list)
+ Return a list of FN’s intermediate reductions across LIST. That
+ is, a list of the intermediate values of the accumulator when
+ ‘-reduce’ (*note -reduce::) (which see) is called with the same
+ arguments.
+
+ This function’s anaphoric counterpart is ‘--reductions’.
+
+ For other folds, see also ‘-reductions’ (*note -reductions::) and
+ ‘-reductions-r’ (*note -reductions-r::).
+
+ (-reductions #'+ '(1 2 3 4))
+ ⇒ (1 3 6 10)
+ (-reductions #'* '(1 2 3 4))
+ ⇒ (1 2 6 24)
+ (--reductions (format "(FN %s %d)" acc it) '(1 2 3))
+ ⇒ (1 "(FN 1 2)" "(FN (FN 1 2) 3)")
+
+ -- Function: -reductions-r (fn list)
+ Return a list of FN’s intermediate reductions across reversed LIST.
+ That is, a list of the intermediate values of the accumulator when
+ ‘-reduce-r’ (*note -reduce-r::) (which see) is called with the same
+ arguments.
+
+ This function’s anaphoric counterpart is ‘--reductions-r’.
+
+ For other folds, see also ‘-reductions-r-from’ (*note
+ -reductions-r-from::) and ‘-reductions’ (*note -reductions::).
+
+ (-reductions-r #'+ '(1 2 3 4))
+ ⇒ (10 9 7 4)
+ (-reductions-r #'* '(1 2 3 4))
+ ⇒ (24 24 12 4)
+ (--reductions-r (format "(FN %d %s)" it acc) '(1 2 3))
+ ⇒ ("(FN 1 (FN 2 3))" "(FN 2 3)" 3)
+
+ -- Function: -count (pred list)
+ Counts the number of items in LIST where (PRED item) is non-‘nil’.
+
+ (-count 'even? '(1 2 3 4 5))
+ ⇒ 2
+ (--count (< it 4) '(1 2 3 4))
+ ⇒ 3
+
+ -- Function: -sum (list)
+ Return the sum of LIST.
+
+ (-sum ())
+ ⇒ 0
+ (-sum '(1))
+ ⇒ 1
+ (-sum '(1 2 3 4))
+ ⇒ 10
+
+ -- Function: -running-sum (list)
+ Return a list with running sums of items in LIST. LIST must be
+ non-empty.
+
+ (-running-sum '(1 2 3 4))
+ ⇒ (1 3 6 10)
+ (-running-sum '(1))
+ ⇒ (1)
+ (-running-sum ())
+ error→ Wrong type argument: consp, nil
+
+ -- Function: -product (list)
+ Return the product of LIST.
+
+ (-product ())
+ ⇒ 1
+ (-product '(1))
+ ⇒ 1
+ (-product '(1 2 3 4))
+ ⇒ 24
+
+ -- Function: -running-product (list)
+ Return a list with running products of items in LIST. LIST must be
+ non-empty.
+
+ (-running-product '(1 2 3 4))
+ ⇒ (1 2 6 24)
+ (-running-product '(1))
+ ⇒ (1)
+ (-running-product ())
+ error→ Wrong type argument: consp, nil
+
+ -- Function: -inits (list)
+ Return all prefixes of LIST.
+
+ (-inits '(1 2 3 4))
+ ⇒ (nil (1) (1 2) (1 2 3) (1 2 3 4))
+ (-inits nil)
+ ⇒ (nil)
+ (-inits '(1))
+ ⇒ (nil (1))
+
+ -- Function: -tails (list)
+ Return all suffixes of LIST
+
+ (-tails '(1 2 3 4))
+ ⇒ ((1 2 3 4) (2 3 4) (3 4) (4) nil)
+ (-tails nil)
+ ⇒ (nil)
+ (-tails '(1))
+ ⇒ ((1) nil)
+
+ -- Function: -common-prefix (&rest lists)
+ Return the longest common prefix of LISTS.
+
+ (-common-prefix '(1))
+ ⇒ (1)
+ (-common-prefix '(1 2) '(3 4) '(1 2))
+ ⇒ ()
+ (-common-prefix '(1 2) '(1 2 3) '(1 2 3 4))
+ ⇒ (1 2)
+
+ -- Function: -common-suffix (&rest lists)
+ Return the longest common suffix of LISTS.
+
+ (-common-suffix '(1))
+ ⇒ (1)
+ (-common-suffix '(1 2) '(3 4) '(1 2))
+ ⇒ ()
+ (-common-suffix '(1 2 3 4) '(2 3 4) '(3 4))
+ ⇒ (3 4)
+
+ -- Function: -min (list)
+ Return the smallest value from LIST of numbers or markers.
+
+ (-min '(0))
+ ⇒ 0
+ (-min '(3 2 1))
+ ⇒ 1
+ (-min '(1 2 3))
+ ⇒ 1
+
+ -- Function: -min-by (comparator list)
+ Take a comparison function COMPARATOR and a LIST and return the
+ least element of the list by the comparison function.
+
+ See also combinator ‘-on’ (*note -on::) which can transform the
+ values before comparing them.
+
+ (-min-by '> '(4 3 6 1))
+ ⇒ 1
+ (--min-by (> (car it) (car other)) '((1 2 3) (2) (3 2)))
+ ⇒ (1 2 3)
+ (--min-by (> (length it) (length other)) '((1 2 3) (2) (3 2)))
+ ⇒ (2)
+
+ -- Function: -max (list)
+ Return the largest value from LIST of numbers or markers.
+
+ (-max '(0))
+ ⇒ 0
+ (-max '(3 2 1))
+ ⇒ 3
+ (-max '(1 2 3))
+ ⇒ 3
+
+ -- Function: -max-by (comparator list)
+ Take a comparison function COMPARATOR and a LIST and return the
+ greatest element of the list by the comparison function.
+
+ See also combinator ‘-on’ (*note -on::) which can transform the
+ values before comparing them.
+
+ (-max-by '> '(4 3 6 1))
+ ⇒ 6
+ (--max-by (> (car it) (car other)) '((1 2 3) (2) (3 2)))
+ ⇒ (3 2)
+ (--max-by (> (length it) (length other)) '((1 2 3) (2) (3 2)))
+ ⇒ (1 2 3)
+
+
+File: dash.info, Node: Unfolding, Next: Predicates, Prev: Reductions, Up: Functions
+
+2.5 Unfolding
+=============
+
+Operations dual to reductions, building lists from a seed value rather
+than consuming a list to produce a single value.
+
+ -- Function: -iterate (fun init n)
+ Return a list of iterated applications of FUN to INIT.
+
+ This means a list of the form:
+
+ (INIT (FUN INIT) (FUN (FUN INIT)) ...)
+
+ N is the length of the returned list.
+
+ (-iterate #'1+ 1 10)
+ ⇒ (1 2 3 4 5 6 7 8 9 10)
+ (-iterate (lambda (x) (+ x x)) 2 5)
+ ⇒ (2 4 8 16 32)
+ (--iterate (* it it) 2 5)
+ ⇒ (2 4 16 256 65536)
+
+ -- Function: -unfold (fun seed)
+ Build a list from SEED using FUN.
+
+ This is "dual" operation to ‘-reduce-r’ (*note -reduce-r::): while
+ -reduce-r consumes a list to produce a single value, ‘-unfold’
+ (*note -unfold::) takes a seed value and builds a (potentially
+ infinite!) list.
+
+ FUN should return ‘nil’ to stop the generating process, or a cons
+ (A . B), where A will be prepended to the result and B is the new
+ seed.
+
+ (-unfold (lambda (x) (unless (= x 0) (cons x (1- x)))) 10)
+ ⇒ (10 9 8 7 6 5 4 3 2 1)
+ (--unfold (when it (cons it (cdr it))) '(1 2 3 4))
+ ⇒ ((1 2 3 4) (2 3 4) (3 4) (4))
+ (--unfold (when it (cons it (butlast it))) '(1 2 3 4))
+ ⇒ ((1 2 3 4) (1 2 3) (1 2) (1))
+
+
+File: dash.info, Node: Predicates, Next: Partitioning, Prev: Unfolding, Up: Functions
+
+2.6 Predicates
+==============
+
+Reductions of one or more lists to a boolean value.
+
+ -- Function: -some (pred list)
+ Return (PRED x) for the first LIST item where (PRED x) is
+ non-‘nil’, else ‘nil’.
+
+ Alias: ‘-any’.
+
+ This function’s anaphoric counterpart is ‘--some’.
+
+ (-some #'stringp '(1 "2" 3))
+ ⇒ t
+ (--some (string-match-p "x" it) '("foo" "axe" "xor"))
+ ⇒ 1
+ (--some (= it-index 3) '(0 1 2))
+ ⇒ nil
+
+ -- Function: -every (pred list)
+ Return non-‘nil’ if PRED returns non-‘nil’ for all items in LIST.
+ If so, return the last such result of PRED. Otherwise, once an
+ item is reached for which PRED returns ‘nil’, return ‘nil’ without
+ calling PRED on any further LIST elements.
+
+ This function is like ‘-every-p’, but on success returns the last
+ non-‘nil’ result of PRED instead of just ‘t’.
+
+ This function’s anaphoric counterpart is ‘--every’.
+
+ (-every #'numberp '(1 2 3))
+ ⇒ t
+ (--every (string-match-p "x" it) '("axe" "xor"))
+ ⇒ 0
+ (--every (= it it-index) '(0 1 3))
+ ⇒ nil
+
+ -- Function: -any? (pred list)
+ Return ‘t’ if (PRED X) is non-‘nil’ for any X in LIST, else ‘nil’.
+
+ Alias: ‘-any-p’, ‘-some?’, ‘-some-p’
+
+ (-any? #'numberp '(nil 0 t))
+ ⇒ t
+ (-any? #'numberp '(nil t t))
+ ⇒ nil
+ (-any? #'null '(1 3 5))
+ ⇒ nil
+
+ -- Function: -all? (pred list)
+ Return ‘t’ if (PRED X) is non-‘nil’ for all X in LIST, else ‘nil’.
+ In the latter case, stop after the first X for which (PRED X) is
+ ‘nil’, without calling PRED on any subsequent elements of LIST.
+
+ The similar function ‘-every’ (*note -every::) is more widely
+ useful, since it returns the last non-‘nil’ result of PRED instead
+ of just ‘t’ on success.
+
+ Alias: ‘-all-p’, ‘-every-p’, ‘-every?’.
+
+ This function’s anaphoric counterpart is ‘--all?’.
+
+ (-all? #'numberp '(1 2 3))
+ ⇒ t
+ (-all? #'numberp '(2 t 6))
+ ⇒ nil
+ (--all? (= 0 (% it 2)) '(2 4 6))
+ ⇒ t
+
+ -- Function: -none? (pred list)
+ Return ‘t’ if (PRED X) is ‘nil’ for all X in LIST, else ‘nil’.
+
+ Alias: ‘-none-p’
+
+ (-none? 'even? '(1 2 3))
+ ⇒ nil
+ (-none? 'even? '(1 3 5))
+ ⇒ t
+ (--none? (= 0 (% it 2)) '(1 2 3))
+ ⇒ nil
+
+ -- Function: -only-some? (pred list)
+ Return ‘t’ if different LIST items both satisfy and do not satisfy
+ PRED. That is, if PRED returns both ‘nil’ for at least one item,
+ and non-‘nil’ for at least one other item in LIST. Return ‘nil’ if
+ all items satisfy the predicate or none of them do.
+
+ Alias: ‘-only-some-p’
+
+ (-only-some? 'even? '(1 2 3))
+ ⇒ t
+ (-only-some? 'even? '(1 3 5))
+ ⇒ nil
+ (-only-some? 'even? '(2 4 6))
+ ⇒ nil
+
+ -- Function: -contains? (list element)
+ Return non-‘nil’ if LIST contains ELEMENT.
+
+ The test for equality is done with ‘equal’, or with ‘-compare-fn’
+ if that’s non-‘nil’.
+
+ Alias: ‘-contains-p’
+
+ (-contains? '(1 2 3) 1)
+ ⇒ t
+ (-contains? '(1 2 3) 2)
+ ⇒ t
+ (-contains? '(1 2 3) 4)
+ ⇒ nil
+
+ -- Function: -same-items? (list list2)
+ Return true if LIST and LIST2 has the same items.
+
+ The order of the elements in the lists does not matter.
+
+ Alias: ‘-same-items-p’
+
+ (-same-items? '(1 2 3) '(1 2 3))
+ ⇒ t
+ (-same-items? '(1 2 3) '(3 2 1))
+ ⇒ t
+ (-same-items? '(1 2 3) '(1 2 3 4))
+ ⇒ nil
+
+ -- Function: -is-prefix? (prefix list)
+ Return non-‘nil’ if PREFIX is a prefix of LIST.
+
+ Alias: ‘-is-prefix-p’.
+
+ (-is-prefix? '(1 2 3) '(1 2 3 4 5))
+ ⇒ t
+ (-is-prefix? '(1 2 3 4 5) '(1 2 3))
+ ⇒ nil
+ (-is-prefix? '(1 3) '(1 2 3 4 5))
+ ⇒ nil
+
+ -- Function: -is-suffix? (suffix list)
+ Return non-‘nil’ if SUFFIX is a suffix of LIST.
+
+ Alias: ‘-is-suffix-p’.
+
+ (-is-suffix? '(3 4 5) '(1 2 3 4 5))
+ ⇒ t
+ (-is-suffix? '(1 2 3 4 5) '(3 4 5))
+ ⇒ nil
+ (-is-suffix? '(3 5) '(1 2 3 4 5))
+ ⇒ nil
+
+ -- Function: -is-infix? (infix list)
+ Return non-‘nil’ if INFIX is infix of LIST.
+
+ This operation runs in O(n^2) time
+
+ Alias: ‘-is-infix-p’
+
+ (-is-infix? '(1 2 3) '(1 2 3 4 5))
+ ⇒ t
+ (-is-infix? '(2 3 4) '(1 2 3 4 5))
+ ⇒ t
+ (-is-infix? '(3 4 5) '(1 2 3 4 5))
+ ⇒ t
+
+ -- Function: -cons-pair? (obj)
+ Return non-‘nil’ if OBJ is a true cons pair. That is, a cons (A .
+ B) where B is not a list.
+
+ Alias: ‘-cons-pair-p’.
+
+ (-cons-pair? '(1 . 2))
+ ⇒ t
+ (-cons-pair? '(1 2))
+ ⇒ nil
+ (-cons-pair? '(1))
+ ⇒ nil
+
+
+File: dash.info, Node: Partitioning, Next: Indexing, Prev: Predicates, Up: Functions
+
+2.7 Partitioning
+================
+
+Functions partitioning the input list into a list of lists.
+
+ -- Function: -split-at (n list)
+ Split LIST into two sublists after the Nth element. The result is
+ a list of two elements (TAKE DROP) where TAKE is a new list of the
+ first N elements of LIST, and DROP is the remaining elements of
+ LIST (not a copy). TAKE and DROP are like the results of ‘-take’
+ (*note -take::) and ‘-drop’ (*note -drop::), respectively, but the
+ split is done in a single list traversal.
+
+ (-split-at 3 '(1 2 3 4 5))
+ ⇒ ((1 2 3) (4 5))
+ (-split-at 17 '(1 2 3 4 5))
+ ⇒ ((1 2 3 4 5) nil)
+ (-split-at 0 '(1 2 3 4 5))
+ ⇒ (nil (1 2 3 4 5))
+
+ -- Function: -split-with (pred list)
+ Split LIST into a prefix satisfying PRED, and the rest. The first
+ sublist is the prefix of LIST with successive elements satisfying
+ PRED, and the second sublist is the remaining elements that do not.
+ The result is like performing
+
+ ((-take-while PRED LIST) (-drop-while PRED LIST))
+
+ but in no more than a single pass through LIST.
+
+ (-split-with 'even? '(1 2 3 4))
+ ⇒ (nil (1 2 3 4))
+ (-split-with 'even? '(2 4 5 6))
+ ⇒ ((2 4) (5 6))
+ (--split-with (< it 4) '(1 2 3 4 3 2 1))
+ ⇒ ((1 2 3) (4 3 2 1))
+
+ -- Macro: -split-on (item list)
+ Split the LIST each time ITEM is found.
+
+ Unlike ‘-partition-by’ (*note -partition-by::), the ITEM is
+ discarded from the results. Empty lists are also removed from the
+ result.
+
+ Comparison is done by ‘equal’.
+
+ See also ‘-split-when’ (*note -split-when::)
+
+ (-split-on '| '(Nil | Leaf a | Node [Tree a]))
+ ⇒ ((Nil) (Leaf a) (Node [Tree a]))
+ (-split-on :endgroup '("a" "b" :endgroup "c" :endgroup "d" "e"))
+ ⇒ (("a" "b") ("c") ("d" "e"))
+ (-split-on :endgroup '("a" "b" :endgroup :endgroup "d" "e"))
+ ⇒ (("a" "b") ("d" "e"))
+
+ -- Function: -split-when (fn list)
+ Split the LIST on each element where FN returns non-‘nil’.
+
+ Unlike ‘-partition-by’ (*note -partition-by::), the "matched"
+ element is discarded from the results. Empty lists are also
+ removed from the result.
+
+ This function can be thought of as a generalization of
+ ‘split-string’.
+
+ (-split-when 'even? '(1 2 3 4 5 6))
+ ⇒ ((1) (3) (5))
+ (-split-when 'even? '(1 2 3 4 6 8 9))
+ ⇒ ((1) (3) (9))
+ (--split-when (memq it '(&optional &rest)) '(a b &optional c d &rest args))
+ ⇒ ((a b) (c d) (args))
+
+ -- Function: -separate (pred list)
+ Split LIST into two sublists based on whether items satisfy PRED.
+ The result is like performing
+
+ ((-filter PRED LIST) (-remove PRED LIST))
+
+ but in a single pass through LIST.
+
+ (-separate (lambda (num) (= 0 (% num 2))) '(1 2 3 4 5 6 7))
+ ⇒ ((2 4 6) (1 3 5 7))
+ (--separate (< it 5) '(3 7 5 9 3 2 1 4 6))
+ ⇒ ((3 3 2 1 4) (7 5 9 6))
+ (-separate 'cdr '((1 2) (1) (1 2 3) (4)))
+ ⇒ (((1 2) (1 2 3)) ((1) (4)))
+
+ -- Function: -partition (n list)
+ Return a new list with the items in LIST grouped into N-sized
+ sublists. If there are not enough items to make the last group
+ N-sized, those items are discarded.
+
+ (-partition 2 '(1 2 3 4 5 6))
+ ⇒ ((1 2) (3 4) (5 6))
+ (-partition 2 '(1 2 3 4 5 6 7))
+ ⇒ ((1 2) (3 4) (5 6))
+ (-partition 3 '(1 2 3 4 5 6 7))
+ ⇒ ((1 2 3) (4 5 6))
+
+ -- Function: -partition-all (n list)
+ Return a new list with the items in LIST grouped into N-sized
+ sublists. The last group may contain less than N items.
+
+ (-partition-all 2 '(1 2 3 4 5 6))
+ ⇒ ((1 2) (3 4) (5 6))
+ (-partition-all 2 '(1 2 3 4 5 6 7))
+ ⇒ ((1 2) (3 4) (5 6) (7))
+ (-partition-all 3 '(1 2 3 4 5 6 7))
+ ⇒ ((1 2 3) (4 5 6) (7))
+
+ -- Function: -partition-in-steps (n step list)
+ Partition LIST into sublists of length N that are STEP items apart.
+ Like ‘-partition-all-in-steps’ (*note -partition-all-in-steps::),
+ but if there are not enough items to make the last group N-sized,
+ those items are discarded.
+
+ (-partition-in-steps 2 1 '(1 2 3 4))
+ ⇒ ((1 2) (2 3) (3 4))
+ (-partition-in-steps 3 2 '(1 2 3 4))
+ ⇒ ((1 2 3))
+ (-partition-in-steps 3 2 '(1 2 3 4 5))
+ ⇒ ((1 2 3) (3 4 5))
+
+ -- Function: -partition-all-in-steps (n step list)
+ Partition LIST into sublists of length N that are STEP items apart.
+ Adjacent groups may overlap if N exceeds the STEP stride. Trailing
+ groups may contain less than N items.
+
+ (-partition-all-in-steps 2 1 '(1 2 3 4))
+ ⇒ ((1 2) (2 3) (3 4) (4))
+ (-partition-all-in-steps 3 2 '(1 2 3 4))
+ ⇒ ((1 2 3) (3 4))
+ (-partition-all-in-steps 3 2 '(1 2 3 4 5))
+ ⇒ ((1 2 3) (3 4 5) (5))
+
+ -- Function: -partition-by (fn list)
+ Apply FN to each item in LIST, splitting it each time FN returns a
+ new value.
+
+ (-partition-by 'even? ())
+ ⇒ ()
+ (-partition-by 'even? '(1 1 2 2 2 3 4 6 8))
+ ⇒ ((1 1) (2 2 2) (3) (4 6 8))
+ (--partition-by (< it 3) '(1 2 3 4 3 2 1))
+ ⇒ ((1 2) (3 4 3) (2 1))
+
+ -- Function: -partition-by-header (fn list)
+ Apply FN to the first item in LIST. That is the header value.
+ Apply FN to each item in LIST, splitting it each time FN returns
+ the header value, but only after seeing at least one other value
+ (the body).
+
+ (--partition-by-header (= it 1) '(1 2 3 1 2 1 2 3 4))
+ ⇒ ((1 2 3) (1 2) (1 2 3 4))
+ (--partition-by-header (> it 0) '(1 2 0 1 0 1 2 3 0))
+ ⇒ ((1 2 0) (1 0) (1 2 3 0))
+ (-partition-by-header 'even? '(2 1 1 1 4 1 3 5 6 6 1))
+ ⇒ ((2 1 1 1) (4 1 3 5) (6 6 1))
+
+ -- Function: -partition-after-pred (pred list)
+ Partition LIST after each element for which PRED returns non-‘nil’.
+
+ This function’s anaphoric counterpart is ‘--partition-after-pred’.
+
+ (-partition-after-pred #'booleanp ())
+ ⇒ ()
+ (-partition-after-pred #'booleanp '(t t))
+ ⇒ ((t) (t))
+ (-partition-after-pred #'booleanp '(0 0 t t 0 t))
+ ⇒ ((0 0 t) (t) (0 t))
+
+ -- Function: -partition-before-pred (pred list)
+ Partition directly before each time PRED is true on an element of
+ LIST.
+
+ (-partition-before-pred #'booleanp ())
+ ⇒ ()
+ (-partition-before-pred #'booleanp '(0 t))
+ ⇒ ((0) (t))
+ (-partition-before-pred #'booleanp '(0 0 t 0 t t))
+ ⇒ ((0 0) (t 0) (t) (t))
+
+ -- Function: -partition-before-item (item list)
+ Partition directly before each time ITEM appears in LIST.
+
+ (-partition-before-item 3 ())
+ ⇒ ()
+ (-partition-before-item 3 '(1))
+ ⇒ ((1))
+ (-partition-before-item 3 '(3))
+ ⇒ ((3))
+
+ -- Function: -partition-after-item (item list)
+ Partition directly after each time ITEM appears in LIST.
+
+ (-partition-after-item 3 ())
+ ⇒ ()
+ (-partition-after-item 3 '(1))
+ ⇒ ((1))
+ (-partition-after-item 3 '(3))
+ ⇒ ((3))
+
+ -- Function: -group-by (fn list)
+ Separate LIST into an alist whose keys are FN applied to the
+ elements of LIST. Keys are compared by ‘equal’.
+
+ (-group-by 'even? ())
+ ⇒ ()
+ (-group-by 'even? '(1 1 2 2 2 3 4 6 8))
+ ⇒ ((nil 1 1 3) (t 2 2 2 4 6 8))
+ (--group-by (car (split-string it "/")) '("a/b" "c/d" "a/e"))
+ ⇒ (("a" "a/b" "a/e") ("c" "c/d"))
+
+
+File: dash.info, Node: Indexing, Next: Set operations, Prev: Partitioning, Up: Functions
+
+2.8 Indexing
+============
+
+Functions retrieving or sorting based on list indices and related
+predicates.
+
+ -- Function: -elem-index (elem list)
+ Return the index of the first element in the given LIST which is
+ equal to the query element ELEM, or ‘nil’ if there is no such
+ element.
+
+ (-elem-index 2 '(6 7 8 2 3 4))
+ ⇒ 3
+ (-elem-index "bar" '("foo" "bar" "baz"))
+ ⇒ 1
+ (-elem-index '(1 2) '((3) (5 6) (1 2) nil))
+ ⇒ 2
+
+ -- Function: -elem-indices (elem list)
+ Return the indices of all elements in LIST equal to the query
+ element ELEM, in ascending order.
+
+ (-elem-indices 2 '(6 7 8 2 3 4 2 1))
+ ⇒ (3 6)
+ (-elem-indices "bar" '("foo" "bar" "baz"))
+ ⇒ (1)
+ (-elem-indices '(1 2) '((3) (1 2) (5 6) (1 2) nil))
+ ⇒ (1 3)
+
+ -- Function: -find-index (pred list)
+ Take a predicate PRED and a LIST and return the index of the first
+ element in the list satisfying the predicate, or ‘nil’ if there is
+ no such element.
+
+ See also ‘-first’ (*note -first::).
+
+ (-find-index 'even? '(2 4 1 6 3 3 5 8))
+ ⇒ 0
+ (--find-index (< 5 it) '(2 4 1 6 3 3 5 8))
+ ⇒ 3
+ (-find-index (-partial 'string-lessp "baz") '("bar" "foo" "baz"))
+ ⇒ 1
+
+ -- Function: -find-last-index (pred list)
+ Take a predicate PRED and a LIST and return the index of the last
+ element in the list satisfying the predicate, or ‘nil’ if there is
+ no such element.
+
+ See also ‘-last’ (*note -last::).
+
+ (-find-last-index 'even? '(2 4 1 6 3 3 5 8))
+ ⇒ 7
+ (--find-last-index (< 5 it) '(2 7 1 6 3 8 5 2))
+ ⇒ 5
+ (-find-last-index (-partial 'string-lessp "baz") '("q" "foo" "baz"))
+ ⇒ 1
+
+ -- Function: -find-indices (pred list)
+ Return the indices of all elements in LIST satisfying the predicate
+ PRED, in ascending order.
+
+ (-find-indices 'even? '(2 4 1 6 3 3 5 8))
+ ⇒ (0 1 3 7)
+ (--find-indices (< 5 it) '(2 4 1 6 3 3 5 8))
+ ⇒ (3 7)
+ (-find-indices (-partial 'string-lessp "baz") '("bar" "foo" "baz"))
+ ⇒ (1)
+
+ -- Function: -grade-up (comparator list)
+ Grade elements of LIST using COMPARATOR relation. This yields a
+ permutation vector such that applying this permutation to LIST
+ sorts it in ascending order.
+
+ (-grade-up #'< '(3 1 4 2 1 3 3))
+ ⇒ (1 4 3 0 5 6 2)
+ (let ((l '(3 1 4 2 1 3 3))) (-select-by-indices (-grade-up #'< l) l))
+ ⇒ (1 1 2 3 3 3 4)
+
+ -- Function: -grade-down (comparator list)
+ Grade elements of LIST using COMPARATOR relation. This yields a
+ permutation vector such that applying this permutation to LIST
+ sorts it in descending order.
+
+ (-grade-down #'< '(3 1 4 2 1 3 3))
+ ⇒ (2 0 5 6 3 1 4)
+ (let ((l '(3 1 4 2 1 3 3))) (-select-by-indices (-grade-down #'< l) l))
+ ⇒ (4 3 3 3 2 1 1)
+
+
+File: dash.info, Node: Set operations, Next: Other list operations, Prev: Indexing, Up: Functions
+
+2.9 Set operations
+==================
+
+Operations pretending lists are sets.
+
+ -- Function: -union (list list2)
+ Return a new list of all elements appearing in either LIST1 or
+ LIST2. Equality is defined by the value of ‘-compare-fn’ if
+ non-‘nil’; otherwise ‘equal’.
+
+ (-union '(1 2 3) '(3 4 5))
+ ⇒ (1 2 3 4 5)
+ (-union '(1 2 3 4) ())
+ ⇒ (1 2 3 4)
+ (-union '(1 1 2 2) '(3 2 1))
+ ⇒ (1 1 2 2 3)
+
+ -- Function: -difference (list list2)
+ Return a new list with only the members of LIST that are not in
+ LIST2. The test for equality is done with ‘equal’, or with
+ ‘-compare-fn’ if that’s non-‘nil’.
+
+ (-difference () ())
+ ⇒ ()
+ (-difference '(1 2 3) '(4 5 6))
+ ⇒ (1 2 3)
+ (-difference '(1 2 3 4) '(3 4 5 6))
+ ⇒ (1 2)
+
+ -- Function: -intersection (list list2)
+ Return a new list of the elements appearing in both LIST1 and
+ LIST2. Equality is defined by the value of ‘-compare-fn’ if
+ non-‘nil’; otherwise ‘equal’.
+
+ (-intersection () ())
+ ⇒ ()
+ (-intersection '(1 2 3) '(4 5 6))
+ ⇒ ()
+ (-intersection '(1 2 3 4) '(3 4 5 6))
+ ⇒ (3 4)
+
+ -- Function: -powerset (list)
+ Return the power set of LIST.
+
+ (-powerset ())
+ ⇒ (nil)
+ (-powerset '(x y z))
+ ⇒ ((x y z) (x y) (x z) (x) (y z) (y) (z) nil)
+
+ -- Function: -permutations (list)
+ Return the permutations of LIST.
+
+ (-permutations ())
+ ⇒ (nil)
+ (-permutations '(1 2))
+ ⇒ ((1 2) (2 1))
+ (-permutations '(a b c))
+ ⇒ ((a b c) (a c b) (b a c) (b c a) (c a b) (c b a))
+
+ -- Function: -distinct (list)
+ Return a new list with all duplicates removed. The test for
+ equality is done with ‘equal’, or with ‘-compare-fn’ if that’s
+ non-‘nil’.
+
+ Alias: ‘-uniq’
+
+ (-distinct ())
+ ⇒ ()
+ (-distinct '(1 2 2 4))
+ ⇒ (1 2 4)
+ (-distinct '(t t t))
+ ⇒ (t)
+
+
+File: dash.info, Node: Other list operations, Next: Tree operations, Prev: Set operations, Up: Functions
+
+2.10 Other list operations
+==========================
+
+Other list functions not fit to be classified elsewhere.
+
+ -- Function: -rotate (n list)
+ Rotate LIST N places to the right (left if N is negative). The
+ time complexity is O(n).
+
+ (-rotate 3 '(1 2 3 4 5 6 7))
+ ⇒ (5 6 7 1 2 3 4)
+ (-rotate -3 '(1 2 3 4 5 6 7))
+ ⇒ (4 5 6 7 1 2 3)
+ (-rotate 16 '(1 2 3 4 5 6 7))
+ ⇒ (6 7 1 2 3 4 5)
+
+ -- Function: -repeat (n x)
+ Return a new list of length N with each element being X. Return
+ ‘nil’ if N is less than 1.
+
+ (-repeat 3 :a)
+ ⇒ (:a :a :a)
+ (-repeat 1 :a)
+ ⇒ (:a)
+ (-repeat 0 :a)
+ ⇒ nil
+
+ -- Function: -cons* (&rest args)
+ Make a new list from the elements of ARGS. The last 2 elements of
+ ARGS are used as the final cons of the result, so if the final
+ element of ARGS is not a list, the result is a dotted list. With
+ no ARGS, return ‘nil’.
+
+ (-cons* 1 2)
+ ⇒ (1 . 2)
+ (-cons* 1 2 3)
+ ⇒ (1 2 . 3)
+ (-cons* 1)
+ ⇒ 1
+
+ -- Function: -snoc (list elem &rest elements)
+ Append ELEM to the end of the list.
+
+ This is like ‘cons’, but operates on the end of list.
+
+ If any ELEMENTS are given, append them to the list as well.
+
+ (-snoc '(1 2 3) 4)
+ ⇒ (1 2 3 4)
+ (-snoc '(1 2 3) 4 5 6)
+ ⇒ (1 2 3 4 5 6)
+ (-snoc '(1 2 3) '(4 5 6))
+ ⇒ (1 2 3 (4 5 6))
+
+ -- Function: -interpose (sep list)
+ Return a new list of all elements in LIST separated by SEP.
+
+ (-interpose "-" ())
+ ⇒ ()
+ (-interpose "-" '("a"))
+ ⇒ ("a")
+ (-interpose "-" '("a" "b" "c"))
+ ⇒ ("a" "-" "b" "-" "c")
+
+ -- Function: -interleave (&rest lists)
+ Return a new list of the first item in each list, then the second
+ etc.
+
+ (-interleave '(1 2) '("a" "b"))
+ ⇒ (1 "a" 2 "b")
+ (-interleave '(1 2) '("a" "b") '("A" "B"))
+ ⇒ (1 "a" "A" 2 "b" "B")
+ (-interleave '(1 2 3) '("a" "b"))
+ ⇒ (1 "a" 2 "b")
+
+ -- Function: -iota (count &optional start step)
+ Return a list containing COUNT numbers. Starts from START and adds
+ STEP each time. The default START is zero, the default STEP is 1.
+ This function takes its name from the corresponding primitive in
+ the APL language.
+
+ (-iota 6)
+ ⇒ (0 1 2 3 4 5)
+ (-iota 4 2.5 -2)
+ ⇒ (2.5 0.5 -1.5 -3.5)
+ (-iota -1)
+ error→ Wrong type argument: natnump, -1
+
+ -- Function: -zip-with (fn list1 list2)
+ Zip the two lists LIST1 and LIST2 using a function FN. This
+ function is applied pairwise taking as first argument element of
+ LIST1 and as second argument element of LIST2 at corresponding
+ position.
+
+ The anaphoric form ‘--zip-with’ binds the elements from LIST1 as
+ symbol ‘it’, and the elements from LIST2 as symbol ‘other’.
+
+ (-zip-with '+ '(1 2 3) '(4 5 6))
+ ⇒ (5 7 9)
+ (-zip-with 'cons '(1 2 3) '(4 5 6))
+ ⇒ ((1 . 4) (2 . 5) (3 . 6))
+ (--zip-with (concat it " and " other) '("Batman" "Jekyll") '("Robin" "Hyde"))
+ ⇒ ("Batman and Robin" "Jekyll and Hyde")
+
+ -- Function: -zip (&rest lists)
+ Zip LISTS together. Group the head of each list, followed by the
+ second elements of each list, and so on. The lengths of the
+ returned groupings are equal to the length of the shortest input
+ list.
+
+ If two lists are provided as arguments, return the groupings as a
+ list of cons cells. Otherwise, return the groupings as a list of
+ lists.
+
+ Use ‘-zip-lists’ (*note -zip-lists::) if you need the return value
+ to always be a list of lists.
+
+ Alias: ‘-zip-pair’
+
+ See also: ‘-zip-lists’ (*note -zip-lists::)
+
+ (-zip '(1 2 3) '(4 5 6))
+ ⇒ ((1 . 4) (2 . 5) (3 . 6))
+ (-zip '(1 2 3) '(4 5 6 7))
+ ⇒ ((1 . 4) (2 . 5) (3 . 6))
+ (-zip '(1 2) '(3 4 5) '(6))
+ ⇒ ((1 3 6))
+
+ -- Function: -zip-lists (&rest lists)
+ Zip LISTS together. Group the head of each list, followed by the
+ second elements of each list, and so on. The lengths of the
+ returned groupings are equal to the length of the shortest input
+ list.
+
+ The return value is always list of lists, which is a difference
+ from ‘-zip-pair’ which returns a cons-cell in case two input lists
+ are provided.
+
+ See also: ‘-zip’ (*note -zip::)
+
+ (-zip-lists '(1 2 3) '(4 5 6))
+ ⇒ ((1 4) (2 5) (3 6))
+ (-zip-lists '(1 2 3) '(4 5 6 7))
+ ⇒ ((1 4) (2 5) (3 6))
+ (-zip-lists '(1 2) '(3 4 5) '(6))
+ ⇒ ((1 3 6))
+
+ -- Function: -zip-fill (fill-value &rest lists)
+ Zip LISTS, with FILL-VALUE padded onto the shorter lists. The
+ lengths of the returned groupings are equal to the length of the
+ longest input list.
+
+ (-zip-fill 0 '(1 2 3 4 5) '(6 7 8 9))
+ ⇒ ((1 . 6) (2 . 7) (3 . 8) (4 . 9) (5 . 0))
+
+ -- Function: -unzip (lists)
+ Unzip LISTS.
+
+ This works just like ‘-zip’ (*note -zip::) but takes a list of
+ lists instead of a variable number of arguments, such that
+
+ (-unzip (-zip L1 L2 L3 ...))
+
+ is identity (given that the lists are the same length).
+
+ Note in particular that calling this on a list of two lists will
+ return a list of cons-cells such that the above identity works.
+
+ See also: ‘-zip’ (*note -zip::)
+
+ (-unzip (-zip '(1 2 3) '(a b c) '("e" "f" "g")))
+ ⇒ ((1 2 3) (a b c) ("e" "f" "g"))
+ (-unzip '((1 2) (3 4) (5 6) (7 8) (9 10)))
+ ⇒ ((1 3 5 7 9) (2 4 6 8 10))
+ (-unzip '((1 2) (3 4)))
+ ⇒ ((1 . 3) (2 . 4))
+
+ -- Function: -cycle (list)
+ Return an infinite circular copy of LIST. The returned list cycles
+ through the elements of LIST and repeats from the beginning.
+
+ (-take 5 (-cycle '(1 2 3)))
+ ⇒ (1 2 3 1 2)
+ (-take 7 (-cycle '(1 "and" 3)))
+ ⇒ (1 "and" 3 1 "and" 3 1)
+ (-zip (-cycle '(1 2 3)) '(1 2))
+ ⇒ ((1 . 1) (2 . 2))
+
+ -- Function: -pad (fill-value &rest lists)
+ Appends FILL-VALUE to the end of each list in LISTS such that they
+ will all have the same length.
+
+ (-pad 0 ())
+ ⇒ (nil)
+ (-pad 0 '(1))
+ ⇒ ((1))
+ (-pad 0 '(1 2 3) '(4 5))
+ ⇒ ((1 2 3) (4 5 0))
+
+ -- Function: -table (fn &rest lists)
+ Compute outer product of LISTS using function FN.
+
+ The function FN should have the same arity as the number of
+ supplied lists.
+
+ The outer product is computed by applying fn to all possible
+ combinations created by taking one element from each list in order.
+ The dimension of the result is (length lists).
+
+ See also: ‘-table-flat’ (*note -table-flat::)
+
+ (-table '* '(1 2 3) '(1 2 3))
+ ⇒ ((1 2 3) (2 4 6) (3 6 9))
+ (-table (lambda (a b) (-sum (-zip-with '* a b))) '((1 2) (3 4)) '((1 3) (2 4)))
+ ⇒ ((7 15) (10 22))
+ (apply '-table 'list (-repeat 3 '(1 2)))
+ ⇒ ((((1 1 1) (2 1 1)) ((1 2 1) (2 2 1))) (((1 1 2) (2 1 2)) ((1 2 2) (2 2 2))))
+
+ -- Function: -table-flat (fn &rest lists)
+ Compute flat outer product of LISTS using function FN.
+
+ The function FN should have the same arity as the number of
+ supplied lists.
+
+ The outer product is computed by applying fn to all possible
+ combinations created by taking one element from each list in order.
+ The results are flattened, ignoring the tensor structure of the
+ result. This is equivalent to calling:
+
+ (-flatten-n (1- (length lists)) (apply ’-table fn lists))
+
+ but the implementation here is much more efficient.
+
+ See also: ‘-flatten-n’ (*note -flatten-n::), ‘-table’ (*note
+ -table::)
+
+ (-table-flat 'list '(1 2 3) '(a b c))
+ ⇒ ((1 a) (2 a) (3 a) (1 b) (2 b) (3 b) (1 c) (2 c) (3 c))
+ (-table-flat '* '(1 2 3) '(1 2 3))
+ ⇒ (1 2 3 2 4 6 3 6 9)
+ (apply '-table-flat 'list (-repeat 3 '(1 2)))
+ ⇒ ((1 1 1) (2 1 1) (1 2 1) (2 2 1) (1 1 2) (2 1 2) (1 2 2) (2 2 2))
+
+ -- Function: -first (pred list)
+ Return the first item in LIST for which PRED returns non-‘nil’.
+ Return ‘nil’ if no such element is found. To get the first item in
+ the list no questions asked, use ‘car’.
+
+ Alias: ‘-find’.
+
+ This function’s anaphoric counterpart is ‘--first’.
+
+ (-first #'natnump '(-1 0 1))
+ ⇒ 0
+ (-first #'null '(1 2 3))
+ ⇒ nil
+ (--first (> it 2) '(1 2 3))
+ ⇒ 3
+
+ -- Function: -last (pred list)
+ Return the last x in LIST where (PRED x) is non-‘nil’, else ‘nil’.
+
+ (-last 'even? '(1 2 3 4 5 6 3 3 3))
+ ⇒ 6
+ (-last 'even? '(1 3 7 5 9))
+ ⇒ nil
+ (--last (> (length it) 3) '("a" "looong" "word" "and" "short" "one"))
+ ⇒ "short"
+
+ -- Function: -first-item (list)
+ Return the first item of LIST, or ‘nil’ on an empty list.
+
+ See also: ‘-second-item’ (*note -second-item::), ‘-last-item’
+ (*note -last-item::).
+
+ (-first-item '(1 2 3))
+ ⇒ 1
+ (-first-item nil)
+ ⇒ nil
+ (let ((list (list 1 2 3))) (setf (-first-item list) 5) list)
+ ⇒ (5 2 3)
+
+ -- Function: -second-item (list)
+ Return the second item of LIST, or ‘nil’ if LIST is too short.
+
+ See also: ‘-third-item’ (*note -third-item::).
+
+ (-second-item '(1 2 3))
+ ⇒ 2
+ (-second-item nil)
+ ⇒ nil
+
+ -- Function: -third-item (list)
+ Return the third item of LIST, or ‘nil’ if LIST is too short.
+
+ See also: ‘-fourth-item’ (*note -fourth-item::).
+
+ (-third-item '(1 2 3))
+ ⇒ 3
+ (-third-item nil)
+ ⇒ nil
+
+ -- Function: -fourth-item (list)
+ Return the fourth item of LIST, or ‘nil’ if LIST is too short.
+
+ See also: ‘-fifth-item’ (*note -fifth-item::).
+
+ (-fourth-item '(1 2 3 4))
+ ⇒ 4
+ (-fourth-item nil)
+ ⇒ nil
+
+ -- Function: -fifth-item (list)
+ Return the fifth item of LIST, or ‘nil’ if LIST is too short.
+
+ See also: ‘-last-item’ (*note -last-item::).
+
+ (-fifth-item '(1 2 3 4 5))
+ ⇒ 5
+ (-fifth-item nil)
+ ⇒ nil
+
+ -- Function: -last-item (list)
+ Return the last item of LIST, or ‘nil’ on an empty list.
+
+ (-last-item '(1 2 3))
+ ⇒ 3
+ (-last-item nil)
+ ⇒ nil
+ (let ((list (list 1 2 3))) (setf (-last-item list) 5) list)
+ ⇒ (1 2 5)
+
+ -- Function: -butlast (list)
+ Return a list of all items in list except for the last.
+
+ (-butlast '(1 2 3))
+ ⇒ (1 2)
+ (-butlast '(1 2))
+ ⇒ (1)
+ (-butlast '(1))
+ ⇒ nil
+
+ -- Function: -sort (comparator list)
+ Sort LIST, stably, comparing elements using COMPARATOR. Return the
+ sorted list. LIST is NOT modified by side effects. COMPARATOR is
+ called with two elements of LIST, and should return non-‘nil’ if
+ the first element should sort before the second.
+
+ (-sort '< '(3 1 2))
+ ⇒ (1 2 3)
+ (-sort '> '(3 1 2))
+ ⇒ (3 2 1)
+ (--sort (< it other) '(3 1 2))
+ ⇒ (1 2 3)
+
+ -- Function: -list (arg)
+ Ensure ARG is a list. If ARG is already a list, return it as is
+ (not a copy). Otherwise, return a new list with ARG as its only
+ element.
+
+ Another supported calling convention is (-list &rest ARGS). In
+ this case, if ARG is not a list, a new list with all of ARGS as
+ elements is returned. This use is supported for backward
+ compatibility and is otherwise deprecated.
+
+ (-list 1)
+ ⇒ (1)
+ (-list ())
+ ⇒ ()
+ (-list '(1 2 3))
+ ⇒ (1 2 3)
+
+ -- Function: -fix (fn list)
+ Compute the (least) fixpoint of FN with initial input LIST.
+
+ FN is called at least once, results are compared with ‘equal’.
+
+ (-fix (lambda (l) (-non-nil (--mapcat (-split-at (/ (length it) 2) it) l))) '((1 2 3)))
+ ⇒ ((1) (2) (3))
+ (let ((l '((starwars scifi) (jedi starwars warrior)))) (--fix (-uniq (--mapcat (cons it (cdr (assq it l))) it)) '(jedi book)))
+ ⇒ (jedi starwars warrior scifi book)
+
+
+File: dash.info, Node: Tree operations, Next: Threading macros, Prev: Other list operations, Up: Functions
+
+2.11 Tree operations
+====================
+
+Functions pretending lists are trees.
+
+ -- Function: -tree-seq (branch children tree)
+ Return a sequence of the nodes in TREE, in depth-first search
+ order.
+
+ BRANCH is a predicate of one argument that returns non-‘nil’ if the
+ passed argument is a branch, that is, a node that can have
+ children.
+
+ CHILDREN is a function of one argument that returns the children of
+ the passed branch node.
+
+ Non-branch nodes are simply copied.
+
+ (-tree-seq 'listp 'identity '(1 (2 3) 4 (5 (6 7))))
+ ⇒ ((1 (2 3) 4 (5 (6 7))) 1 (2 3) 2 3 4 (5 (6 7)) 5 (6 7) 6 7)
+ (-tree-seq 'listp 'reverse '(1 (2 3) 4 (5 (6 7))))
+ ⇒ ((1 (2 3) 4 (5 (6 7))) (5 (6 7)) (6 7) 7 6 5 4 (2 3) 3 2 1)
+ (--tree-seq (vectorp it) (append it nil) [1 [2 3] 4 [5 [6 7]]])
+ ⇒ ([1 [2 3] 4 [5 [6 7]]] 1 [2 3] 2 3 4 [5 [6 7]] 5 [6 7] 6 7)
+
+ -- Function: -tree-map (fn tree)
+ Apply FN to each element of TREE while preserving the tree
+ structure.
+
+ (-tree-map '1+ '(1 (2 3) (4 (5 6) 7)))
+ ⇒ (2 (3 4) (5 (6 7) 8))
+ (-tree-map '(lambda (x) (cons x (expt 2 x))) '(1 (2 3) 4))
+ ⇒ ((1 . 2) ((2 . 4) (3 . 8)) (4 . 16))
+ (--tree-map (length it) '("<body>" ("<p>" "text" "</p>") "</body>"))
+ ⇒ (6 (3 4 4) 7)
+
+ -- Function: -tree-map-nodes (pred fun tree)
+ Call FUN on each node of TREE that satisfies PRED.
+
+ If PRED returns ‘nil’, continue descending down this node. If PRED
+ returns non-‘nil’, apply FUN to this node and do not descend
+ further.
+
+ (-tree-map-nodes 'vectorp (lambda (x) (-sum (append x nil))) '(1 [2 3] 4 (5 [6 7] 8)))
+ ⇒ (1 5 4 (5 13 8))
+ (-tree-map-nodes 'keywordp (lambda (x) (symbol-name x)) '(1 :foo 4 ((5 6 :bar) :baz 8)))
+ ⇒ (1 ":foo" 4 ((5 6 ":bar") ":baz" 8))
+ (--tree-map-nodes (eq (car-safe it) 'add-mode) (-concat it (list :mode 'emacs-lisp-mode)) '(with-mode emacs-lisp-mode (foo bar) (add-mode a b) (baz (add-mode c d))))
+ ⇒ (with-mode emacs-lisp-mode (foo bar) (add-mode a b :mode emacs-lisp-mode) (baz (add-mode c d :mode emacs-lisp-mode)))
+
+ -- Function: -tree-reduce (fn tree)
+ Use FN to reduce elements of list TREE. If elements of TREE are
+ lists themselves, apply the reduction recursively.
+
+ FN is first applied to first element of the list and second
+ element, then on this result and third element from the list etc.
+
+ See ‘-reduce-r’ (*note -reduce-r::) for how exactly are lists of
+ zero or one element handled.
+
+ (-tree-reduce '+ '(1 (2 3) (4 5)))
+ ⇒ 15
+ (-tree-reduce 'concat '("strings" (" on" " various") ((" levels"))))
+ ⇒ "strings on various levels"
+ (--tree-reduce (cond ((stringp it) (concat it " " acc)) (t (let ((sn (symbol-name it))) (concat "<" sn ">" acc "</" sn ">")))) '(body (p "some words") (div "more" (b "bold") "words")))
+ ⇒ "<body><p>some words</p> <div>more <b>bold</b> words</div></body>"
+
+ -- Function: -tree-reduce-from (fn init-value tree)
+ Use FN to reduce elements of list TREE. If elements of TREE are
+ lists themselves, apply the reduction recursively.
+
+ FN is first applied to INIT-VALUE and first element of the list,
+ then on this result and second element from the list etc.
+
+ The initial value is ignored on cons pairs as they always contain
+ two elements.
+
+ (-tree-reduce-from '+ 1 '(1 (1 1) ((1))))
+ ⇒ 8
+ (--tree-reduce-from (-concat acc (list it)) nil '(1 (2 3 (4 5)) (6 7)))
+ ⇒ ((7 6) ((5 4) 3 2) 1)
+
+ -- Function: -tree-mapreduce (fn folder tree)
+ Apply FN to each element of TREE, and make a list of the results.
+ If elements of TREE are lists themselves, apply FN recursively to
+ elements of these nested lists.
+
+ Then reduce the resulting lists using FOLDER and initial value
+ INIT-VALUE. See ‘-reduce-r-from’ (*note -reduce-r-from::).
+
+ This is the same as calling ‘-tree-reduce’ (*note -tree-reduce::)
+ after ‘-tree-map’ (*note -tree-map::) but is twice as fast as it
+ only traverse the structure once.
+
+ (-tree-mapreduce 'list 'append '(1 (2 (3 4) (5 6)) (7 (8 9))))
+ ⇒ (1 2 3 4 5 6 7 8 9)
+ (--tree-mapreduce 1 (+ it acc) '(1 (2 (4 9) (2 1)) (7 (4 3))))
+ ⇒ 9
+ (--tree-mapreduce 0 (max acc (1+ it)) '(1 (2 (4 9) (2 1)) (7 (4 3))))
+ ⇒ 3
+
+ -- Function: -tree-mapreduce-from (fn folder init-value tree)
+ Apply FN to each element of TREE, and make a list of the results.
+ If elements of TREE are lists themselves, apply FN recursively to
+ elements of these nested lists.
+
+ Then reduce the resulting lists using FOLDER and initial value
+ INIT-VALUE. See ‘-reduce-r-from’ (*note -reduce-r-from::).
+
+ This is the same as calling ‘-tree-reduce-from’ (*note
+ -tree-reduce-from::) after ‘-tree-map’ (*note -tree-map::) but is
+ twice as fast as it only traverse the structure once.
+
+ (-tree-mapreduce-from 'identity '* 1 '(1 (2 (3 4) (5 6)) (7 (8 9))))
+ ⇒ 362880
+ (--tree-mapreduce-from (+ it it) (cons it acc) nil '(1 (2 (4 9) (2 1)) (7 (4 3))))
+ ⇒ (2 (4 (8 18) (4 2)) (14 (8 6)))
+ (concat "{" (--tree-mapreduce-from (cond ((-cons-pair? it) (concat (symbol-name (car it)) " -> " (symbol-name (cdr it)))) (t (concat (symbol-name it) " : {"))) (concat it (unless (or (equal acc "}") (equal (substring it (1- (length it))) "{")) ", ") acc) "}" '((elisp-mode (foo (bar . booze)) (baz . qux)) (c-mode (foo . bla) (bum . bam)))))
+ ⇒ "{elisp-mode : {foo : {bar -> booze}, baz -> qux}, c-mode : {foo -> bla, bum -> bam}}"
+
+ -- Function: -clone (list)
+ Create a deep copy of LIST. The new list has the same elements and
+ structure but all cons are replaced with new ones. This is useful
+ when you need to clone a structure such as plist or alist.
+
+ (let* ((a '(1 2 3)) (b (-clone a))) (nreverse a) b)
+ ⇒ (1 2 3)
+
+
+File: dash.info, Node: Threading macros, Next: Binding, Prev: Tree operations, Up: Functions
+
+2.12 Threading macros
+=====================
+
+Macros that conditionally combine sequential forms for brevity or
+readability.
+
+ -- Macro: -> (x &optional form &rest more)
+ Thread the expr through the forms. Insert X as the second item in
+ the first form, making a list of it if it is not a list already.
+ If there are more forms, insert the first form as the second item
+ in second form, etc.
+
+ (-> '(2 3 5))
+ ⇒ (2 3 5)
+ (-> '(2 3 5) (append '(8 13)))
+ ⇒ (2 3 5 8 13)
+ (-> '(2 3 5) (append '(8 13)) (-slice 1 -1))
+ ⇒ (3 5 8)
+
+ -- Macro: ->> (x &optional form &rest more)
+ Thread the expr through the forms. Insert X as the last item in
+ the first form, making a list of it if it is not a list already.
+ If there are more forms, insert the first form as the last item in
+ second form, etc.
+
+ (->> '(1 2 3) (-map 'square))
+ ⇒ (1 4 9)
+ (->> '(1 2 3) (-map 'square) (-remove 'even?))
+ ⇒ (1 9)
+ (->> '(1 2 3) (-map 'square) (-reduce '+))
+ ⇒ 14
+
+ -- Macro: --> (x &rest forms)
+ Starting with the value of X, thread each expression through FORMS.
+
+ Insert X at the position signified by the symbol ‘it’ in the first
+ form. If there are more forms, insert the first form at the
+ position signified by ‘it’ in in second form, etc.
+
+ (--> "def" (concat "abc" it "ghi"))
+ ⇒ "abcdefghi"
+ (--> "def" (concat "abc" it "ghi") (upcase it))
+ ⇒ "ABCDEFGHI"
+ (--> "def" (concat "abc" it "ghi") upcase)
+ ⇒ "ABCDEFGHI"
+
+ -- Macro: -as-> (value variable &rest forms)
+ Starting with VALUE, thread VARIABLE through FORMS.
+
+ In the first form, bind VARIABLE to VALUE. In the second form,
+ bind VARIABLE to the result of the first form, and so forth.
+
+ (-as-> 3 my-var (1+ my-var) (list my-var) (mapcar (lambda (ele) (* 2 ele)) my-var))
+ ⇒ (8)
+ (-as-> 3 my-var 1+)
+ ⇒ 4
+ (-as-> 3 my-var)
+ ⇒ 3
+
+ -- Macro: -some-> (x &optional form &rest more)
+ When expr is non-‘nil’, thread it through the first form (via ‘->’
+ (*note ->::)), and when that result is non-‘nil’, through the next
+ form, etc.
+
+ (-some-> '(2 3 5))
+ ⇒ (2 3 5)
+ (-some-> 5 square)
+ ⇒ 25
+ (-some-> 5 even? square)
+ ⇒ nil
+
+ -- Macro: -some->> (x &optional form &rest more)
+ When expr is non-‘nil’, thread it through the first form (via ‘->>’
+ (*note ->>::)), and when that result is non-‘nil’, through the next
+ form, etc.
+
+ (-some->> '(1 2 3) (-map 'square))
+ ⇒ (1 4 9)
+ (-some->> '(1 3 5) (-last 'even?) (+ 100))
+ ⇒ nil
+ (-some->> '(2 4 6) (-last 'even?) (+ 100))
+ ⇒ 106
+
+ -- Macro: -some--> (expr &rest forms)
+ Thread EXPR through FORMS via ‘-->’ (*note -->::), while the result
+ is non-‘nil’. When EXPR evaluates to non-‘nil’, thread the result
+ through the first of FORMS, and when that result is non-‘nil’,
+ thread it through the next form, etc.
+
+ (-some--> "def" (concat "abc" it "ghi"))
+ ⇒ "abcdefghi"
+ (-some--> nil (concat "abc" it "ghi"))
+ ⇒ nil
+ (-some--> '(0 1) (-remove #'natnump it) (append it it) (-map #'1+ it))
+ ⇒ ()
+
+ -- Macro: -doto (init &rest forms)
+ Evaluate INIT and pass it as argument to FORMS with ‘->’ (*note
+ ->::). The RESULT of evaluating INIT is threaded through each of
+ FORMS individually using ‘->’ (*note ->::), which see. The return
+ value is RESULT, which FORMS may have modified by side effect.
+
+ (-doto (list 1 2 3) pop pop)
+ ⇒ (3)
+ (-doto (cons 1 2) (setcar 3) (setcdr 4))
+ ⇒ (3 . 4)
+ (gethash 'k (--doto (make-hash-table) (puthash 'k 'v it)))
+ ⇒ v
+
+
+File: dash.info, Node: Binding, Next: Side effects, Prev: Threading macros, Up: Functions
+
+2.13 Binding
+============
+
+Macros that combine ‘let’ and ‘let*’ with destructuring and flow
+control.
+
+ -- Macro: -when-let ((var val) &rest body)
+ If VAL evaluates to non-‘nil’, bind it to VAR and execute body.
+
+ Note: binding is done according to ‘-let’ (*note -let::).
+
+ (-when-let (match-index (string-match "d" "abcd")) (+ match-index 2))
+ ⇒ 5
+ (-when-let ((&plist :foo foo) (list :foo "foo")) foo)
+ ⇒ "foo"
+ (-when-let ((&plist :foo foo) (list :bar "bar")) foo)
+ ⇒ nil
+
+ -- Macro: -when-let* (vars-vals &rest body)
+ If all VALS evaluate to true, bind them to their corresponding VARS
+ and execute body. VARS-VALS should be a list of (VAR VAL) pairs.
+
+ Note: binding is done according to ‘-let*’ (*note -let*::). VALS
+ are evaluated sequentially, and evaluation stops after the first
+ ‘nil’ VAL is encountered.
+
+ (-when-let* ((x 5) (y 3) (z (+ y 4))) (+ x y z))
+ ⇒ 15
+ (-when-let* ((x 5) (y nil) (z 7)) (+ x y z))
+ ⇒ nil
+
+ -- Macro: -if-let ((var val) then &rest else)
+ If VAL evaluates to non-‘nil’, bind it to VAR and do THEN,
+ otherwise do ELSE.
+
+ Note: binding is done according to ‘-let’ (*note -let::).
+
+ (-if-let (match-index (string-match "d" "abc")) (+ match-index 3) 7)
+ ⇒ 7
+ (--if-let (even? 4) it nil)
+ ⇒ t
+
+ -- Macro: -if-let* (vars-vals then &rest else)
+ If all VALS evaluate to true, bind them to their corresponding VARS
+ and do THEN, otherwise do ELSE. VARS-VALS should be a list of (VAR
+ VAL) pairs.
+
+ Note: binding is done according to ‘-let*’ (*note -let*::). VALS
+ are evaluated sequentially, and evaluation stops after the first
+ ‘nil’ VAL is encountered.
+
+ (-if-let* ((x 5) (y 3) (z 7)) (+ x y z) "foo")
+ ⇒ 15
+ (-if-let* ((x 5) (y nil) (z 7)) (+ x y z) "foo")
+ ⇒ "foo"
+ (-if-let* (((_ _ x) '(nil nil 7))) x)
+ ⇒ 7
+
+ -- Macro: -let (varlist &rest body)
+ Bind variables according to VARLIST then eval BODY.
+
+ VARLIST is a list of lists of the form (PATTERN SOURCE). Each
+ PATTERN is matched against the SOURCE "structurally". SOURCE is
+ only evaluated once for each PATTERN. Each PATTERN is matched
+ recursively, and can therefore contain sub-patterns which are
+ matched against corresponding sub-expressions of SOURCE.
+
+ All the SOURCEs are evalled before any symbols are bound (i.e. "in
+ parallel").
+
+ If VARLIST only contains one (PATTERN SOURCE) element, you can
+ optionally specify it using a vector and discarding the outer-most
+ parens. Thus
+
+ (-let ((PATTERN SOURCE)) ...)
+
+ becomes
+
+ (-let [PATTERN SOURCE] ...).
+
+ ‘-let’ (*note -let::) uses a convention of not binding places
+ (symbols) starting with _ whenever it’s possible. You can use this
+ to skip over entries you don’t care about. However, this is not
+ *always* possible (as a result of implementation) and these symbols
+ might get bound to undefined values.
+
+ Following is the overview of supported patterns. Remember that
+ patterns can be matched recursively, so every a, b, aK in the
+ following can be a matching construct and not necessarily a
+ symbol/variable.
+
+ Symbol:
+
+ a - bind the SOURCE to A. This is just like regular ‘let’.
+
+ Conses and lists:
+
+ (a) - bind ‘car’ of cons/list to A
+
+ (a . b) - bind car of cons to A and ‘cdr’ to B
+
+ (a b) - bind car of list to A and ‘cadr’ to B
+
+ (a1 a2 a3 ...) - bind 0th car of list to A1, 1st to A2, 2nd to
+ A3...
+
+ (a1 a2 a3 ... aN . rest) - as above, but bind the Nth cdr to REST.
+
+ Vectors:
+
+ [a] - bind 0th element of a non-list sequence to A (works with
+ vectors, strings, bit arrays...)
+
+ [a1 a2 a3 ...] - bind 0th element of non-list sequence to A0, 1st
+ to A1, 2nd to A2, ... If the PATTERN is shorter than SOURCE, the
+ values at places not in PATTERN are ignored. If the PATTERN is
+ longer than SOURCE, an ‘error’ is thrown.
+
+ [a1 a2 a3 ... &rest rest] - as above, but bind the rest of the
+ sequence to REST. This is conceptually the same as improper list
+ matching (a1 a2 ... aN . rest)
+
+ Key/value stores:
+
+ (&plist key0 a0 ... keyN aN) - bind value mapped by keyK in the
+ SOURCE plist to aK. If the value is not found, aK is ‘nil’. Uses
+ ‘plist-get’ to fetch values.
+
+ (&alist key0 a0 ... keyN aN) - bind value mapped by keyK in the
+ SOURCE alist to aK. If the value is not found, aK is ‘nil’. Uses
+ ‘assoc’ to fetch values.
+
+ (&hash key0 a0 ... keyN aN) - bind value mapped by keyK in the
+ SOURCE hash table to aK. If the value is not found, aK is ‘nil’.
+ Uses ‘gethash’ to fetch values.
+
+ Further, special keyword &keys supports "inline" matching of
+ plist-like key-value pairs, similarly to &keys keyword of
+ ‘cl-defun’.
+
+ (a1 a2 ... aN &keys key1 b1 ... keyN bK)
+
+ This binds N values from the list to a1 ... aN, then interprets the
+ cdr as a plist (see key/value matching above).
+
+ A shorthand notation for kv-destructuring exists which allows the
+ patterns be optionally left out and derived from the key name in
+ the following fashion:
+
+ - a key :foo is converted into ‘foo’ pattern, - a key ’bar is
+ converted into ‘bar’ pattern, - a key "baz" is converted into ‘baz’
+ pattern.
+
+ That is, the entire value under the key is bound to the derived
+ variable without any further destructuring.
+
+ This is possible only when the form following the key is not a
+ valid pattern (i.e. not a symbol, a cons cell or a vector).
+ Otherwise the matching proceeds as usual and in case of an invalid
+ spec fails with an error.
+
+ Thus the patterns are normalized as follows:
+
+ ;; derive all the missing patterns (&plist :foo ’bar "baz") =>
+ (&plist :foo foo ’bar bar "baz" baz)
+
+ ;; we can specify some but not others (&plist :foo ’bar
+ explicit-bar) => (&plist :foo foo ’bar explicit-bar)
+
+ ;; nothing happens, we store :foo in x (&plist :foo x) => (&plist
+ :foo x)
+
+ ;; nothing happens, we match recursively (&plist :foo (a b c)) =>
+ (&plist :foo (a b c))
+
+ You can name the source using the syntax SYMBOL &as PATTERN. This
+ syntax works with lists (proper or improper), vectors and all types
+ of maps.
+
+ (list &as a b c) (list 1 2 3)
+
+ binds A to 1, B to 2, C to 3 and LIST to (1 2 3).
+
+ Similarly:
+
+ (bounds &as beg . end) (cons 1 2)
+
+ binds BEG to 1, END to 2 and BOUNDS to (1 . 2).
+
+ (items &as first . rest) (list 1 2 3)
+
+ binds FIRST to 1, REST to (2 3) and ITEMS to (1 2 3)
+
+ [vect &as _ b c] [1 2 3]
+
+ binds B to 2, C to 3 and VECT to [1 2 3] (_ avoids binding as
+ usual).
+
+ (plist &as &plist :b b) (list :a 1 :b 2 :c 3)
+
+ binds B to 2 and PLIST to (:a 1 :b 2 :c 3). Same for &alist and
+ &hash.
+
+ This is especially useful when we want to capture the result of a
+ computation and destructure at the same time. Consider the form
+ (function-returning-complex-structure) returning a list of two
+ vectors with two items each. We want to capture this entire result
+ and pass it to another computation, but at the same time we want to
+ get the second item from each vector. We can achieve it with
+ pattern
+
+ (result &as [_ a] [_ b]) (function-returning-complex-structure)
+
+ Note: Clojure programmers may know this feature as the ":as
+ binding". The difference is that we put the &as at the front
+ because we need to support improper list binding.
+
+ (-let (([a (b c) d] [1 (2 3) 4])) (list a b c d))
+ ⇒ (1 2 3 4)
+ (-let [(a b c . d) (list 1 2 3 4 5 6)] (list a b c d))
+ ⇒ (1 2 3 (4 5 6))
+ (-let [(&plist :foo foo :bar bar) (list :baz 3 :foo 1 :qux 4 :bar 2)] (list foo bar))
+ ⇒ (1 2)
+
+ -- Macro: -let* (varlist &rest body)
+ Bind variables according to VARLIST then eval BODY.
+
+ VARLIST is a list of lists of the form (PATTERN SOURCE). Each
+ PATTERN is matched against the SOURCE structurally. SOURCE is only
+ evaluated once for each PATTERN.
+
+ Each SOURCE can refer to the symbols already bound by this VARLIST.
+ This is useful if you want to destructure SOURCE recursively but
+ also want to name the intermediate structures.
+
+ See ‘-let’ (*note -let::) for the list of all possible patterns.
+
+ (-let* (((a . b) (cons 1 2)) ((c . d) (cons 3 4))) (list a b c d))
+ ⇒ (1 2 3 4)
+ (-let* (((a . b) (cons 1 (cons 2 3))) ((c . d) b)) (list a b c d))
+ ⇒ (1 (2 . 3) 2 3)
+ (-let* (((&alist "foo" foo "bar" bar) (list (cons "foo" 1) (cons "bar" (list 'a 'b 'c)))) ((a b c) bar)) (list foo a b c bar))
+ ⇒ (1 a b c (a b c))
+
+ -- Macro: -lambda (match-form &rest body)
+ Return a lambda which destructures its input as MATCH-FORM and
+ executes BODY.
+
+ Note that you have to enclose the MATCH-FORM in a pair of parens,
+ such that:
+
+ (-lambda (x) body) (-lambda (x y ...) body)
+
+ has the usual semantics of ‘lambda’. Furthermore, these get
+ translated into normal ‘lambda’, so there is no performance
+ penalty.
+
+ See ‘-let’ (*note -let::) for a description of the destructuring
+ mechanism.
+
+ (-map (-lambda ((x y)) (+ x y)) '((1 2) (3 4) (5 6)))
+ ⇒ (3 7 11)
+ (-map (-lambda ([x y]) (+ x y)) '([1 2] [3 4] [5 6]))
+ ⇒ (3 7 11)
+ (funcall (-lambda ((_ . a) (_ . b)) (-concat a b)) '(1 2 3) '(4 5 6))
+ ⇒ (2 3 5 6)
+
+ -- Macro: -setq ([match-form val] ...)
+ Bind each MATCH-FORM to the value of its VAL.
+
+ MATCH-FORM destructuring is done according to the rules of ‘-let’
+ (*note -let::).
+
+ This macro allows you to bind multiple variables by destructuring
+ the value, so for example:
+
+ (-setq (a b) x (&plist :c c) plist)
+
+ expands roughly speaking to the following code
+
+ (setq a (car x) b (cadr x) c (plist-get plist :c))
+
+ Care is taken to only evaluate each VAL once so that in case of
+ multiple assignments it does not cause unexpected side effects.
+
+ (let (a) (-setq a 1) a)
+ ⇒ 1
+ (let (a b) (-setq (a b) (list 1 2)) (list a b))
+ ⇒ (1 2)
+ (let (c) (-setq (&plist :c c) (list :c "c")) c)
+ ⇒ "c"
+
+
+File: dash.info, Node: Side effects, Next: Destructive operations, Prev: Binding, Up: Functions
+
+2.14 Side effects
+=================
+
+Functions iterating over lists for side effect only.
+
+ -- Function: -each (list fn)
+ Call FN on each element of LIST. Return ‘nil’; this function is
+ intended for side effects.
+
+ Its anaphoric counterpart is ‘--each’.
+
+ For access to the current element’s index in LIST, see
+ ‘-each-indexed’ (*note -each-indexed::).
+
+ (let (l) (-each '(1 2 3) (lambda (x) (push x l))) l)
+ ⇒ (3 2 1)
+ (let (l) (--each '(1 2 3) (push it l)) l)
+ ⇒ (3 2 1)
+ (-each '(1 2 3) #'identity)
+ ⇒ nil
+
+ -- Function: -each-while (list pred fn)
+ Call FN on each ITEM in LIST, while (PRED ITEM) is non-‘nil’. Once
+ an ITEM is reached for which PRED returns ‘nil’, FN is no longer
+ called. Return ‘nil’; this function is intended for side effects.
+
+ Its anaphoric counterpart is ‘--each-while’.
+
+ (let (l) (-each-while '(2 4 5 6) #'even? (lambda (x) (push x l))) l)
+ ⇒ (4 2)
+ (let (l) (--each-while '(1 2 3 4) (< it 3) (push it l)) l)
+ ⇒ (2 1)
+ (let ((s 0)) (--each-while '(1 3 4 5) (< it 5) (setq s (+ s it))) s)
+ ⇒ 8
+
+ -- Function: -each-indexed (list fn)
+ Call FN on each index and element of LIST. For each ITEM at INDEX
+ in LIST, call (funcall FN INDEX ITEM). Return ‘nil’; this function
+ is intended for side effects.
+
+ See also: ‘-map-indexed’ (*note -map-indexed::).
+
+ (let (l) (-each-indexed '(a b c) (lambda (i x) (push (list x i) l))) l)
+ ⇒ ((c 2) (b 1) (a 0))
+ (let (l) (--each-indexed '(a b c) (push (list it it-index) l)) l)
+ ⇒ ((c 2) (b 1) (a 0))
+ (let (l) (--each-indexed () (push it l)) l)
+ ⇒ ()
+
+ -- Function: -each-r (list fn)
+ Call FN on each element of LIST in reversed order. Return ‘nil’;
+ this function is intended for side effects.
+
+ Its anaphoric counterpart is ‘--each-r’.
+
+ (let (l) (-each-r '(1 2 3) (lambda (x) (push x l))) l)
+ ⇒ (1 2 3)
+ (let (l) (--each-r '(1 2 3) (push it l)) l)
+ ⇒ (1 2 3)
+ (-each-r '(1 2 3) #'identity)
+ ⇒ nil
+
+ -- Function: -each-r-while (list pred fn)
+ Call FN on each ITEM in reversed LIST, while (PRED ITEM) is
+ non-‘nil’. Once an ITEM is reached for which PRED returns ‘nil’,
+ FN is no longer called. Return ‘nil’; this function is intended
+ for side effects.
+
+ Its anaphoric counterpart is ‘--each-r-while’.
+
+ (let (l) (-each-r-while '(2 4 5 6) #'even? (lambda (x) (push x l))) l)
+ ⇒ (6)
+ (let (l) (--each-r-while '(1 2 3 4) (>= it 3) (push it l)) l)
+ ⇒ (3 4)
+ (let ((s 0)) (--each-r-while '(1 2 3 5) (> it 1) (setq s (+ s it))) s)
+ ⇒ 10
+
+ -- Function: -dotimes (num fn)
+ Call FN NUM times, presumably for side effects. FN is called with
+ a single argument on successive integers running from 0, inclusive,
+ to NUM, exclusive. FN is not called if NUM is less than 1.
+
+ This function’s anaphoric counterpart is ‘--dotimes’.
+
+ (let (s) (-dotimes 3 (lambda (n) (push n s))) s)
+ ⇒ (2 1 0)
+ (let (s) (-dotimes 0 (lambda (n) (push n s))) s)
+ ⇒ ()
+ (let (s) (--dotimes 5 (push it s)) s)
+ ⇒ (4 3 2 1 0)
+
+
+File: dash.info, Node: Destructive operations, Next: Function combinators, Prev: Side effects, Up: Functions
+
+2.15 Destructive operations
+===========================
+
+Macros that modify variables holding lists.
+
+ -- Macro: !cons (car cdr)
+ Destructive: Set CDR to the cons of CAR and CDR.
+
+ (let (l) (!cons 5 l) l)
+ ⇒ (5)
+ (let ((l '(3))) (!cons 5 l) l)
+ ⇒ (5 3)
+
+ -- Macro: !cdr (list)
+ Destructive: Set LIST to the cdr of LIST.
+
+ (let ((l '(3))) (!cdr l) l)
+ ⇒ ()
+ (let ((l '(3 5))) (!cdr l) l)
+ ⇒ (5)
+
+
+File: dash.info, Node: Function combinators, Prev: Destructive operations, Up: Functions
+
+2.16 Function combinators
+=========================
+
+Functions that manipulate and compose other functions.
+
+ -- Function: -partial (fun &rest args)
+ Return a function that is a partial application of FUN to ARGS.
+ ARGS is a list of the first N arguments to pass to FUN. The result
+ is a new function which does the same as FUN, except that the first
+ N arguments are fixed at the values with which this function was
+ called.
+
+ (funcall (-partial #'+ 5))
+ ⇒ 5
+ (funcall (-partial #'- 5) 3)
+ ⇒ 2
+ (funcall (-partial #'+ 5 2) 3)
+ ⇒ 10
+
+ -- Function: -rpartial (fn &rest args)
+ Return a function that is a partial application of FN to ARGS.
+ ARGS is a list of the last N arguments to pass to FN. The result
+ is a new function which does the same as FN, except that the last N
+ arguments are fixed at the values with which this function was
+ called. This is like ‘-partial’ (*note -partial::), except the
+ arguments are fixed starting from the right rather than the left.
+
+ (funcall (-rpartial #'- 5))
+ ⇒ -5
+ (funcall (-rpartial #'- 5) 8)
+ ⇒ 3
+ (funcall (-rpartial #'- 5 2) 10)
+ ⇒ 3
+
+ -- Function: -juxt (&rest fns)
+ Return a function that is the juxtaposition of FNS. The returned
+ function takes a variable number of ARGS, applies each of FNS in
+ turn to ARGS, and returns the list of results.
+
+ (funcall (-juxt) 1 2)
+ ⇒ ()
+ (funcall (-juxt #'+ #'- #'* #'/) 7 5)
+ ⇒ (12 2 35 1)
+ (mapcar (-juxt #'number-to-string #'1+) '(1 2))
+ ⇒ (("1" 2) ("2" 3))
+
+ -- Function: -compose (&rest fns)
+ Compose FNS into a single composite function. Return a function
+ that takes a variable number of ARGS, applies the last function in
+ FNS to ARGS, and returns the result of calling each remaining
+ function on the result of the previous function, right-to-left. If
+ no FNS are given, return a variadic ‘identity’ function.
+
+ (funcall (-compose #'- #'1+ #'+) 1 2 3)
+ ⇒ -7
+ (funcall (-compose #'identity #'1+) 3)
+ ⇒ 4
+ (mapcar (-compose #'not #'stringp) '(nil ""))
+ ⇒ (t nil)
+
+ -- Function: -applify (fn)
+ Return a function that applies FN to a single list of args. This
+ changes the arity of FN from taking N distinct arguments to taking
+ 1 argument which is a list of N arguments.
+
+ (funcall (-applify #'+) nil)
+ ⇒ 0
+ (mapcar (-applify #'+) '((1 1 1) (1 2 3) (5 5 5)))
+ ⇒ (3 6 15)
+ (funcall (-applify #'<) '(3 6))
+ ⇒ t
+
+ -- Function: -on (op trans)
+ Return a function that calls TRANS on each arg and OP on the
+ results. The returned function takes a variable number of
+ arguments, calls the function TRANS on each one in turn, and then
+ passes those results as the list of arguments to OP, in the same
+ order.
+
+ For example, the following pairs of expressions are morally
+ equivalent:
+
+ (funcall (-on #’+ #’1+) 1 2 3) = (+ (1+ 1) (1+ 2) (1+ 3)) (funcall
+ (-on #’+ #’1+)) = (+)
+
+ (-sort (-on #'< #'length) '((1 2 3) (1) (1 2)))
+ ⇒ ((1) (1 2) (1 2 3))
+ (funcall (-on #'min #'string-to-number) "22" "2" "1" "12")
+ ⇒ 1
+ (-min-by (-on #'> #'length) '((1 2 3) (4) (1 2)))
+ ⇒ (4)
+
+ -- Function: -flip (fn)
+ Return a function that calls FN with its arguments reversed. The
+ returned function takes the same number of arguments as FN.
+
+ For example, the following two expressions are morally equivalent:
+
+ (funcall (-flip #’-) 1 2) = (- 2 1)
+
+ See also: ‘-rotate-args’ (*note -rotate-args::).
+
+ (-sort (-flip #'<) '(4 3 6 1))
+ ⇒ (6 4 3 1)
+ (funcall (-flip #'-) 3 2 1 10)
+ ⇒ 4
+ (funcall (-flip #'1+) 1)
+ ⇒ 2
+
+ -- Function: -rotate-args (n fn)
+ Return a function that calls FN with args rotated N places to the
+ right. The returned function takes the same number of arguments as
+ FN, rotates the list of arguments N places to the right (left if N
+ is negative) just like ‘-rotate’ (*note -rotate::), and applies FN
+ to the result.
+
+ See also: ‘-flip’ (*note -flip::).
+
+ (funcall (-rotate-args -1 #'list) 1 2 3 4)
+ ⇒ (2 3 4 1)
+ (funcall (-rotate-args 1 #'-) 1 10 100)
+ ⇒ 89
+ (funcall (-rotate-args 2 #'list) 3 4 5 1 2)
+ ⇒ (1 2 3 4 5)
+
+ -- Function: -const (c)
+ Return a function that returns C ignoring any additional arguments.
+
+ In types: a -> b -> a
+
+ (funcall (-const 2) 1 3 "foo")
+ ⇒ 2
+ (mapcar (-const 1) '("a" "b" "c" "d"))
+ ⇒ (1 1 1 1)
+ (-sum (mapcar (-const 1) '("a" "b" "c" "d")))
+ ⇒ 4
+
+ -- Macro: -cut (&rest params)
+ Take n-ary function and n arguments and specialize some of them.
+ Arguments denoted by <> will be left unspecialized.
+
+ See SRFI-26 for detailed description.
+
+ (funcall (-cut list 1 <> 3 <> 5) 2 4)
+ ⇒ (1 2 3 4 5)
+ (-map (-cut funcall <> 5) `(1+ 1- ,(lambda (x) (/ 1.0 x))))
+ ⇒ (6 4 0.2)
+ (-map (-cut <> 1 2 3) '(list vector string))
+ ⇒ ((1 2 3) [1 2 3] "\1\2\3")
+
+ -- Function: -not (pred)
+ Return a predicate that negates the result of PRED. The returned
+ predicate passes its arguments to PRED. If PRED returns ‘nil’, the
+ result is non-‘nil’; otherwise the result is ‘nil’.
+
+ See also: ‘-andfn’ (*note -andfn::) and ‘-orfn’ (*note -orfn::).
+
+ (funcall (-not #'numberp) "5")
+ ⇒ t
+ (-sort (-not #'<) '(5 2 1 0 6))
+ ⇒ (6 5 2 1 0)
+ (-filter (-not (-partial #'< 4)) '(1 2 3 4 5 6 7 8))
+ ⇒ (1 2 3 4)
+
+ -- Function: -orfn (&rest preds)
+ Return a predicate that returns the first non-‘nil’ result of
+ PREDS. The returned predicate takes a variable number of
+ arguments, passes them to each predicate in PREDS in turn until one
+ of them returns non-‘nil’, and returns that non-‘nil’ result
+ without calling the remaining PREDS. If all PREDS return ‘nil’, or
+ if no PREDS are given, the returned predicate returns ‘nil’.
+
+ See also: ‘-andfn’ (*note -andfn::) and ‘-not’ (*note -not::).
+
+ (-filter (-orfn #'natnump #'booleanp) '(1 nil "a" -4 b c t))
+ ⇒ (1 nil t)
+ (funcall (-orfn #'symbolp (-cut string-match-p "x" <>)) "axe")
+ ⇒ 1
+ (funcall (-orfn #'= #'+) 1 1)
+ ⇒ t
+
+ -- Function: -andfn (&rest preds)
+ Return a predicate that returns non-‘nil’ if all PREDS do so. The
+ returned predicate P takes a variable number of arguments and
+ passes them to each predicate in PREDS in turn. If any one of
+ PREDS returns ‘nil’, P also returns ‘nil’ without calling the
+ remaining PREDS. If all PREDS return non-‘nil’, P returns the last
+ such value. If no PREDS are given, P always returns non-‘nil’.
+
+ See also: ‘-orfn’ (*note -orfn::) and ‘-not’ (*note -not::).
+
+ (-filter (-andfn #'numberp (-cut < <> 5)) '(a 1 b 6 c 2))
+ ⇒ (1 2)
+ (mapcar (-andfn #'numberp #'1+) '(a 1 b 6))
+ ⇒ (nil 2 nil 7)
+ (funcall (-andfn #'= #'+) 1 1)
+ ⇒ 2
+
+ -- Function: -iteratefn (fn n)
+ Return a function FN composed N times with itself.
+
+ FN is a unary function. If you need to use a function of higher
+ arity, use ‘-applify’ (*note -applify::) first to turn it into a
+ unary function.
+
+ With n = 0, this acts as identity function.
+
+ In types: (a -> a) -> Int -> a -> a.
+
+ This function satisfies the following law:
+
+ (funcall (-iteratefn fn n) init) = (-last-item (-iterate fn init
+ (1+ n))).
+
+ (funcall (-iteratefn (lambda (x) (* x x)) 3) 2)
+ ⇒ 256
+ (funcall (-iteratefn '1+ 3) 1)
+ ⇒ 4
+ (funcall (-iteratefn 'cdr 3) '(1 2 3 4 5))
+ ⇒ (4 5)
+
+ -- Function: -fixfn (fn &optional equal-test halt-test)
+ Return a function that computes the (least) fixpoint of FN.
+
+ FN must be a unary function. The returned lambda takes a single
+ argument, X, the initial value for the fixpoint iteration. The
+ iteration halts when either of the following conditions is
+ satisfied:
+
+ 1. Iteration converges to the fixpoint, with equality being tested
+ using EQUAL-TEST. If EQUAL-TEST is not specified, ‘equal’ is used.
+ For functions over the floating point numbers, it may be necessary
+ to provide an appropriate approximate comparison test.
+
+ 2. HALT-TEST returns a non-‘nil’ value. HALT-TEST defaults to a
+ simple counter that returns ‘t’ after ‘-fixfn-max-iterations’, to
+ guard against infinite iteration. Otherwise, HALT-TEST must be a
+ function that accepts a single argument, the current value of X,
+ and returns non-‘nil’ as long as iteration should continue. In
+ this way, a more sophisticated convergence test may be supplied by
+ the caller.
+
+ The return value of the lambda is either the fixpoint or, if
+ iteration halted before converging, a cons with car ‘halted’ and
+ cdr the final output from HALT-TEST.
+
+ In types: (a -> a) -> a -> a.
+
+ (funcall (-fixfn #'cos #'approx=) 0.7)
+ ⇒ 0.7390851332151607
+ (funcall (-fixfn (lambda (x) (expt (+ x 10) 0.25))) 2.0)
+ ⇒ 1.8555845286409378
+ (funcall (-fixfn #'sin #'approx=) 0.1)
+ ⇒ (halted . t)
+
+ -- Function: -prodfn (&rest fns)
+ Return a function that applies each of FNS to each of a list of
+ arguments.
+
+ Takes a list of N functions and returns a function that takes a
+ list of length N, applying Ith function to Ith element of the input
+ list. Returns a list of length N.
+
+ In types (for N=2): ((a -> b), (c -> d)) -> (a, c) -> (b, d)
+
+ This function satisfies the following laws:
+
+ (-compose (-prodfn f g ...) (-prodfn f’ g’ ...)) = (-prodfn
+ (-compose f f’) (-compose g g’) ...)
+
+ (-prodfn f g ...) = (-juxt (-compose f (-partial #’nth 0))
+ (-compose g (-partial #’nth 1)) ...)
+
+ (-compose (-prodfn f g ...) (-juxt f’ g’ ...)) = (-juxt (-compose f
+ f’) (-compose g g’) ...)
+
+ (-compose (-partial #’nth n) (-prod f1 f2 ...)) = (-compose fn
+ (-partial #’nth n))
+
+ (funcall (-prodfn '1+ '1- 'number-to-string) '(1 2 3))
+ ⇒ (2 1 "3")
+ (-map (-prodfn '1+ '1-) '((1 2) (3 4) (5 6) (7 8)))
+ ⇒ ((2 1) (4 3) (6 5) (8 7))
+ (apply '+ (funcall (-prodfn 'length 'string-to-number) '((1 2 3) "15")))
+ ⇒ 18
+
+
+File: dash.info, Node: Development, Next: FDL, Prev: Functions, Up: Top
+
+3 Development
+*************
+
+The Dash repository is hosted on GitHub at
+<https://github.com/magnars/dash.el>.
+
+* Menu:
+
+* Contribute:: How to contribute.
+* Contributors:: List of contributors.
+
+
+File: dash.info, Node: Contribute, Next: Contributors, Up: Development
+
+3.1 Contribute
+==============
+
+Yes, please do. Pure functions in the list manipulation realm only,
+please. There’s a suite of examples/tests in ‘dev/examples.el’, so
+remember to add tests for your additions, or they may get broken later.
+
+ Run the tests with ‘make check’. Regenerate the docs with ‘make
+docs’. Contributors are encouraged to install these commands as a Git
+pre-commit hook, so that the tests are always running and the docs are
+always in sync:
+
+ $ cp dev/pre-commit.sh .git/hooks/pre-commit
+
+ Oh, and don’t edit ‘README.md’ or ‘dash.texi’ directly, as they are
+auto-generated. Instead, change their respective templates
+‘readme-template.md’ or ‘dash-template.texi’.
+
+ To ensure that Dash can be distributed with GNU ELPA or Emacs, we
+require that all contributors assign copyright to the Free Software
+Foundation. For more on this, *note (emacs)Copyright Assignment::.
+
+
+File: dash.info, Node: Contributors, Prev: Contribute, Up: Development
+
+3.2 Contributors
+================
+
+ • Matus Goljer (https://github.com/Fuco1) contributed lots of
+ features and functions.
+ • Takafumi Arakaki (https://github.com/tkf) contributed ‘-group-by’.
+ • tali713 (https://github.com/tali713) is the author of ‘-applify’.
+ • Víctor M. Valenzuela (https://github.com/vemv) contributed
+ ‘-repeat’.
+ • Nic Ferrier (https://github.com/nicferrier) contributed ‘-cons*’.
+ • Wilfred Hughes (https://github.com/Wilfred) contributed ‘-slice’,
+ ‘-first-item’, and ‘-last-item’.
+ • Emanuel Evans (https://github.com/shosti) contributed ‘-if-let’,
+ ‘-when-let’, and ‘-insert-at’.
+ • Johan Andersson (https://github.com/rejeep) contributed ‘-sum’,
+ ‘-product’, and ‘-same-items?’.
+ • Christina Whyte (https://github.com/kurisuwhyte) contributed
+ ‘-compose’.
+ • Steve Lamb (https://github.com/steventlamb) contributed ‘-cycle’,
+ ‘-pad’, ‘-annotate’, ‘-zip-fill’, and a variadic version of ‘-zip’.
+ • Fredrik Bergroth (https://github.com/fbergroth) made the ‘-if-let’
+ family use ‘-let’ destructuring and improved the script for
+ generating documentation.
+ • Mark Oteiza (https://github.com/holomorph) contributed ‘-iota’ and
+ the script to create an Info manual.
+ • Vasilij Schneidermann (https://github.com/wasamasa) contributed
+ ‘-some’.
+ • William West (https://github.com/occidens) made ‘-fixfn’ more
+ robust at handling floats.
+ • Cam Saul (https://github.com/camsaul) contributed ‘-some->’,
+ ‘-some->>’, and ‘-some-->’.
+ • Basil L. Contovounesios (https://github.com/basil-conto)
+ contributed ‘-common-prefix’, ‘-common-suffix’, and various other
+ improvements.
+ • Paul Pogonyshev (https://github.com/doublep) contributed ‘-each-r’
+ and ‘-each-r-while’.
+
+ Thanks!
+
+ New contributors are very welcome. *Note Contribute::.
+
+
+File: dash.info, Node: FDL, Next: GPL, Prev: Development, Up: Top
+
+Appendix A GNU Free Documentation License
+*****************************************
+
+ Version 1.3, 3 November 2008
+
+ Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
+ <https://fsf.org/>
+
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ 0. PREAMBLE
+
+ The purpose of this License is to make a manual, textbook, or other
+ functional and useful document “free” in the sense of freedom: to
+ assure everyone the effective freedom to copy and redistribute it,
+ with or without modifying it, either commercially or
+ noncommercially. Secondarily, this License preserves for the
+ author and publisher a way to get credit for their work, while not
+ being considered responsible for modifications made by others.
+
+ This License is a kind of “copyleft”, which means that derivative
+ works of the document must themselves be free in the same sense.
+ It complements the GNU General Public License, which is a copyleft
+ license designed for free software.
+
+ We have designed this License in order to use it for manuals for
+ free software, because free software needs free documentation: a
+ free program should come with manuals providing the same freedoms
+ that the software does. But this License is not limited to
+ software manuals; it can be used for any textual work, regardless
+ of subject matter or whether it is published as a printed book. We
+ recommend this License principally for works whose purpose is
+ instruction or reference.
+
+ 1. APPLICABILITY AND DEFINITIONS
+
+ This License applies to any manual or other work, in any medium,
+ that contains a notice placed by the copyright holder saying it can
+ be distributed under the terms of this License. Such a notice
+ grants a world-wide, royalty-free license, unlimited in duration,
+ to use that work under the conditions stated herein. The
+ “Document”, below, refers to any such manual or work. Any member
+ of the public is a licensee, and is addressed as “you”. You accept
+ the license if you copy, modify or distribute the work in a way
+ requiring permission under copyright law.
+
+ A “Modified Version” of the Document means any work containing the
+ Document or a portion of it, either copied verbatim, or with
+ modifications and/or translated into another language.
+
+ A “Secondary Section” is a named appendix or a front-matter section
+ of the Document that deals exclusively with the relationship of the
+ publishers or authors of the Document to the Document’s overall
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+ is in part a textbook of mathematics, a Secondary Section may not
+ explain any mathematics.) The relationship could be a matter of
+ historical connection with the subject or with related matters, or
+ of legal, commercial, philosophical, ethical or political position
+ regarding them.
+
+ The “Invariant Sections” are certain Secondary Sections whose
+ titles are designated, as being those of Invariant Sections, in the
+ notice that says that the Document is released under this License.
+ If a section does not fit the above definition of Secondary then it
+ is not allowed to be designated as Invariant. The Document may
+ contain zero Invariant Sections. If the Document does not identify
+ any Invariant Sections then there are none.
+
+ The “Cover Texts” are certain short passages of text that are
+ listed, as Front-Cover Texts or Back-Cover Texts, in the notice
+ that says that the Document is released under this License. A
+ Front-Cover Text may be at most 5 words, and a Back-Cover Text may
+ be at most 25 words.
+
+ A “Transparent” copy of the Document means a machine-readable copy,
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+ suitable for input to text formatters. A copy made in an otherwise
+ Transparent file format whose markup, or absence of markup, has
+ been arranged to thwart or discourage subsequent modification by
+ readers is not Transparent. An image format is not Transparent if
+ used for any substantial amount of text. A copy that is not
+ “Transparent” is called “Opaque”.
+
+ Examples of suitable formats for Transparent copies include plain
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+ Opaque formats include proprietary formats that can be read and
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+ the DTD and/or processing tools are not generally available, and
+ the machine-generated HTML, PostScript or PDF produced by some word
+ processors for output purposes only.
+
+ The “Title Page” means, for a printed book, the title page itself,
+ plus such following pages as are needed to hold, legibly, the
+ material this License requires to appear in the title page. For
+ works in formats which do not have any title page as such, “Title
+ Page” means the text near the most prominent appearance of the
+ work’s title, preceding the beginning of the body of the text.
+
+ The “publisher” means any person or entity that distributes copies
+ of the Document to the public.
+
+ A section “Entitled XYZ” means a named subunit of the Document
+ whose title either is precisely XYZ or contains XYZ in parentheses
+ following text that translates XYZ in another language. (Here XYZ
+ stands for a specific section name mentioned below, such as
+ “Acknowledgements”, “Dedications”, “Endorsements”, or “History”.)
+ To “Preserve the Title” of such a section when you modify the
+ Document means that it remains a section “Entitled XYZ” according
+ to this definition.
+
+ The Document may include Warranty Disclaimers next to the notice
+ which states that this License applies to the Document. These
+ Warranty Disclaimers are considered to be included by reference in
+ this License, but only as regards disclaiming warranties: any other
+ implication that these Warranty Disclaimers may have is void and
+ has no effect on the meaning of this License.
+
+ 2. VERBATIM COPYING
+
+ You may copy and distribute the Document in any medium, either
+ commercially or noncommercially, provided that this License, the
+ copyright notices, and the license notice saying this License
+ applies to the Document are reproduced in all copies, and that you
+ add no other conditions whatsoever to those of this License. You
+ may not use technical measures to obstruct or control the reading
+ or further copying of the copies you make or distribute. However,
+ you may accept compensation in exchange for copies. If you
+ distribute a large enough number of copies you must also follow the
+ conditions in section 3.
+
+ You may also lend copies, under the same conditions stated above,
+ and you may publicly display copies.
+
+ 3. COPYING IN QUANTITY
+
+ If you publish printed copies (or copies in media that commonly
+ have printed covers) of the Document, numbering more than 100, and
+ the Document’s license notice requires Cover Texts, you must
+ enclose the copies in covers that carry, clearly and legibly, all
+ these Cover Texts: Front-Cover Texts on the front cover, and
+ Back-Cover Texts on the back cover. Both covers must also clearly
+ and legibly identify you as the publisher of these copies. The
+ front cover must present the full title with all words of the title
+ equally prominent and visible. You may add other material on the
+ covers in addition. Copying with changes limited to the covers, as
+ long as they preserve the title of the Document and satisfy these
+ conditions, can be treated as verbatim copying in other respects.
+
+ If the required texts for either cover are too voluminous to fit
+ legibly, you should put the first ones listed (as many as fit
+ reasonably) on the actual cover, and continue the rest onto
+ adjacent pages.
+
+ If you publish or distribute Opaque copies of the Document
+ numbering more than 100, you must either include a machine-readable
+ Transparent copy along with each Opaque copy, or state in or with
+ each Opaque copy a computer-network location from which the general
+ network-using public has access to download using public-standard
+ network protocols a complete Transparent copy of the Document, free
+ of added material. If you use the latter option, you must take
+ reasonably prudent steps, when you begin distribution of Opaque
+ copies in quantity, to ensure that this Transparent copy will
+ remain thus accessible at the stated location until at least one
+ year after the last time you distribute an Opaque copy (directly or
+ through your agents or retailers) of that edition to the public.
+
+ It is requested, but not required, that you contact the authors of
+ the Document well before redistributing any large number of copies,
+ to give them a chance to provide you with an updated version of the
+ Document.
+
+ 4. MODIFICATIONS
+
+ You may copy and distribute a Modified Version of the Document
+ under the conditions of sections 2 and 3 above, provided that you
+ release the Modified Version under precisely this License, with the
+ Modified Version filling the role of the Document, thus licensing
+ distribution and modification of the Modified Version to whoever
+ possesses a copy of it. In addition, you must do these things in
+ the Modified Version:
+
+ A. Use in the Title Page (and on the covers, if any) a title
+ distinct from that of the Document, and from those of previous
+ versions (which should, if there were any, be listed in the
+ History section of the Document). You may use the same title
+ as a previous version if the original publisher of that
+ version gives permission.
+
+ B. List on the Title Page, as authors, one or more persons or
+ entities responsible for authorship of the modifications in
+ the Modified Version, together with at least five of the
+ principal authors of the Document (all of its principal
+ authors, if it has fewer than five), unless they release you
+ from this requirement.
+
+ C. State on the Title page the name of the publisher of the
+ Modified Version, as the publisher.
+
+ D. Preserve all the copyright notices of the Document.
+
+ E. Add an appropriate copyright notice for your modifications
+ adjacent to the other copyright notices.
+
+ F. Include, immediately after the copyright notices, a license
+ notice giving the public permission to use the Modified
+ Version under the terms of this License, in the form shown in
+ the Addendum below.
+
+ G. Preserve in that license notice the full lists of Invariant
+ Sections and required Cover Texts given in the Document’s
+ license notice.
+
+ H. Include an unaltered copy of this License.
+
+ I. Preserve the section Entitled “History”, Preserve its Title,
+ and add to it an item stating at least the title, year, new
+ authors, and publisher of the Modified Version as given on the
+ Title Page. If there is no section Entitled “History” in the
+ Document, create one stating the title, year, authors, and
+ publisher of the Document as given on its Title Page, then add
+ an item describing the Modified Version as stated in the
+ previous sentence.
+
+ J. Preserve the network location, if any, given in the Document
+ for public access to a Transparent copy of the Document, and
+ likewise the network locations given in the Document for
+ previous versions it was based on. These may be placed in the
+ “History” section. You may omit a network location for a work
+ that was published at least four years before the Document
+ itself, or if the original publisher of the version it refers
+ to gives permission.
+
+ K. For any section Entitled “Acknowledgements” or “Dedications”,
+ Preserve the Title of the section, and preserve in the section
+ all the substance and tone of each of the contributor
+ acknowledgements and/or dedications given therein.
+
+ L. Preserve all the Invariant Sections of the Document, unaltered
+ in their text and in their titles. Section numbers or the
+ equivalent are not considered part of the section titles.
+
+ M. Delete any section Entitled “Endorsements”. Such a section
+ may not be included in the Modified Version.
+
+ N. Do not retitle any existing section to be Entitled
+ “Endorsements” or to conflict in title with any Invariant
+ Section.
+
+ O. Preserve any Warranty Disclaimers.
+
+ If the Modified Version includes new front-matter sections or
+ appendices that qualify as Secondary Sections and contain no
+ material copied from the Document, you may at your option designate
+ some or all of these sections as invariant. To do this, add their
+ titles to the list of Invariant Sections in the Modified Version’s
+ license notice. These titles must be distinct from any other
+ section titles.
+
+ You may add a section Entitled “Endorsements”, provided it contains
+ nothing but endorsements of your Modified Version by various
+ parties—for example, statements of peer review or that the text has
+ been approved by an organization as the authoritative definition of
+ a standard.
+
+ You may add a passage of up to five words as a Front-Cover Text,
+ and a passage of up to 25 words as a Back-Cover Text, to the end of
+ the list of Cover Texts in the Modified Version. Only one passage
+ of Front-Cover Text and one of Back-Cover Text may be added by (or
+ through arrangements made by) any one entity. If the Document
+ already includes a cover text for the same cover, previously added
+ by you or by arrangement made by the same entity you are acting on
+ behalf of, you may not add another; but you may replace the old
+ one, on explicit permission from the previous publisher that added
+ the old one.
+
+ The author(s) and publisher(s) of the Document do not by this
+ License give permission to use their names for publicity for or to
+ assert or imply endorsement of any Modified Version.
+
+ 5. COMBINING DOCUMENTS
+
+ You may combine the Document with other documents released under
+ this License, under the terms defined in section 4 above for
+ modified versions, provided that you include in the combination all
+ of the Invariant Sections of all of the original documents,
+ unmodified, and list them all as Invariant Sections of your
+ combined work in its license notice, and that you preserve all
+ their Warranty Disclaimers.
+
+ The combined work need only contain one copy of this License, and
+ multiple identical Invariant Sections may be replaced with a single
+ copy. If there are multiple Invariant Sections with the same name
+ but different contents, make the title of each such section unique
+ by adding at the end of it, in parentheses, the name of the
+ original author or publisher of that section if known, or else a
+ unique number. Make the same adjustment to the section titles in
+ the list of Invariant Sections in the license notice of the
+ combined work.
+
+ In the combination, you must combine any sections Entitled
+ “History” in the various original documents, forming one section
+ Entitled “History”; likewise combine any sections Entitled
+ “Acknowledgements”, and any sections Entitled “Dedications”. You
+ must delete all sections Entitled “Endorsements.”
+
+ 6. COLLECTIONS OF DOCUMENTS
+
+ You may make a collection consisting of the Document and other
+ documents released under this License, and replace the individual
+ copies of this License in the various documents with a single copy
+ that is included in the collection, provided that you follow the
+ rules of this License for verbatim copying of each of the documents
+ in all other respects.
+
+ You may extract a single document from such a collection, and
+ distribute it individually under this License, provided you insert
+ a copy of this License into the extracted document, and follow this
+ License in all other respects regarding verbatim copying of that
+ document.
+
+ 7. AGGREGATION WITH INDEPENDENT WORKS
+
+ A compilation of the Document or its derivatives with other
+ separate and independent documents or works, in or on a volume of a
+ storage or distribution medium, is called an “aggregate” if the
+ copyright resulting from the compilation is not used to limit the
+ legal rights of the compilation’s users beyond what the individual
+ works permit. When the Document is included in an aggregate, this
+ License does not apply to the other works in the aggregate which
+ are not themselves derivative works of the Document.
+
+ If the Cover Text requirement of section 3 is applicable to these
+ copies of the Document, then if the Document is less than one half
+ of the entire aggregate, the Document’s Cover Texts may be placed
+ on covers that bracket the Document within the aggregate, or the
+ electronic equivalent of covers if the Document is in electronic
+ form. Otherwise they must appear on printed covers that bracket
+ the whole aggregate.
+
+ 8. TRANSLATION
+
+ Translation is considered a kind of modification, so you may
+ distribute translations of the Document under the terms of section
+ 4. Replacing Invariant Sections with translations requires special
+ permission from their copyright holders, but you may include
+ translations of some or all Invariant Sections in addition to the
+ original versions of these Invariant Sections. You may include a
+ translation of this License, and all the license notices in the
+ Document, and any Warranty Disclaimers, provided that you also
+ include the original English version of this License and the
+ original versions of those notices and disclaimers. In case of a
+ disagreement between the translation and the original version of
+ this License or a notice or disclaimer, the original version will
+ prevail.
+
+ If a section in the Document is Entitled “Acknowledgements”,
+ “Dedications”, or “History”, the requirement (section 4) to
+ Preserve its Title (section 1) will typically require changing the
+ actual title.
+
+ 9. TERMINATION
+
+ You may not copy, modify, sublicense, or distribute the Document
+ except as expressly provided under this License. Any attempt
+ otherwise to copy, modify, sublicense, or distribute it is void,
+ and will automatically terminate your rights under this License.
+
+ However, if you cease all violation of this License, then your
+ license from a particular copyright holder is reinstated (a)
+ provisionally, unless and until the copyright holder explicitly and
+ finally terminates your license, and (b) permanently, if the
+ copyright holder fails to notify you of the violation by some
+ reasonable means prior to 60 days after the cessation.
+
+ Moreover, your license from a particular copyright holder is
+ reinstated permanently if the copyright holder notifies you of the
+ violation by some reasonable means, this is the first time you have
+ received notice of violation of this License (for any work) from
+ that copyright holder, and you cure the violation prior to 30 days
+ after your receipt of the notice.
+
+ Termination of your rights under this section does not terminate
+ the licenses of parties who have received copies or rights from you
+ under this License. If your rights have been terminated and not
+ permanently reinstated, receipt of a copy of some or all of the
+ same material does not give you any rights to use it.
+
+ 10. FUTURE REVISIONS OF THIS LICENSE
+
+ The Free Software Foundation may publish new, revised versions of
+ the GNU Free Documentation License from time to time. Such new
+ versions will be similar in spirit to the present version, but may
+ differ in detail to address new problems or concerns. See
+ <https://www.gnu.org/licenses/>.
+
+ Each version of the License is given a distinguishing version
+ number. If the Document specifies that a particular numbered
+ version of this License “or any later version” applies to it, you
+ have the option of following the terms and conditions either of
+ that specified version or of any later version that has been
+ published (not as a draft) by the Free Software Foundation. If the
+ Document does not specify a version number of this License, you may
+ choose any version ever published (not as a draft) by the Free
+ Software Foundation. If the Document specifies that a proxy can
+ decide which future versions of this License can be used, that
+ proxy’s public statement of acceptance of a version permanently
+ authorizes you to choose that version for the Document.
+
+ 11. RELICENSING
+
+ “Massive Multiauthor Collaboration Site” (or “MMC Site”) means any
+ World Wide Web server that publishes copyrightable works and also
+ provides prominent facilities for anybody to edit those works. A
+ public wiki that anybody can edit is an example of such a server.
+ A “Massive Multiauthor Collaboration” (or “MMC”) contained in the
+ site means any set of copyrightable works thus published on the MMC
+ site.
+
+ “CC-BY-SA” means the Creative Commons Attribution-Share Alike 3.0
+ license published by Creative Commons Corporation, a not-for-profit
+ corporation with a principal place of business in San Francisco,
+ California, as well as future copyleft versions of that license
+ published by that same organization.
+
+ “Incorporate” means to publish or republish a Document, in whole or
+ in part, as part of another Document.
+
+ An MMC is “eligible for relicensing” if it is licensed under this
+ License, and if all works that were first published under this
+ License somewhere other than this MMC, and subsequently
+ incorporated in whole or in part into the MMC, (1) had no cover
+ texts or invariant sections, and (2) were thus incorporated prior
+ to November 1, 2008.
+
+ The operator of an MMC Site may republish an MMC contained in the
+ site under CC-BY-SA on the same site at any time before August 1,
+ 2009, provided the MMC is eligible for relicensing.
+
+ADDENDUM: How to use this License for your documents
+====================================================
+
+To use this License in a document you have written, include a copy of
+the License in the document and put the following copyright and license
+notices just after the title page:
+
+ Copyright (C) YEAR YOUR NAME.
+ Permission is granted to copy, distribute and/or modify this document
+ under the terms of the GNU Free Documentation License, Version 1.3
+ or any later version published by the Free Software Foundation;
+ with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
+ Texts. A copy of the license is included in the section entitled ``GNU
+ Free Documentation License''.
+
+ If you have Invariant Sections, Front-Cover Texts and Back-Cover
+Texts, replace the “with...Texts.” line with this:
+
+ with the Invariant Sections being LIST THEIR TITLES, with
+ the Front-Cover Texts being LIST, and with the Back-Cover Texts
+ being LIST.
+
+ If you have Invariant Sections without Cover Texts, or some other
+combination of the three, merge those two alternatives to suit the
+situation.
+
+ If your document contains nontrivial examples of program code, we
+recommend releasing these examples in parallel under your choice of free
+software license, such as the GNU General Public License, to permit
+their use in free software.
+
+
+File: dash.info, Node: GPL, Next: Index, Prev: FDL, Up: Top
+
+Appendix B GNU General Public License
+*************************************
+
+ Version 3, 29 June 2007
+
+ Copyright © 2007 Free Software Foundation, Inc. <https://fsf.org/>
+
+ Everyone is permitted to copy and distribute verbatim copies of this
+ license document, but changing it is not allowed.
+
+Preamble
+========
+
+The GNU General Public License is a free, copyleft license for software
+and other kinds of works.
+
+ The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works. By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program—to make sure it remains free
+software for all its users. We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors. You can apply it to
+your programs, too.
+
+ When we speak of free software, we are referring to freedom, not
+price. Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+
+ To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights. Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
+
+ For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received. You must make sure that they, too, receive
+or can get the source code. And you must show them these terms so they
+know their rights.
+
+ Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
+
+ For the developers’ and authors’ protection, the GPL clearly explains
+that there is no warranty for this free software. For both users’ and
+authors’ sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+
+ Some devices are designed to deny users access to install or run
+modified versions of the software inside them, although the manufacturer
+can do so. This is fundamentally incompatible with the aim of
+protecting users’ freedom to change the software. The systematic
+pattern of such abuse occurs in the area of products for individuals to
+use, which is precisely where it is most unacceptable. Therefore, we
+have designed this version of the GPL to prohibit the practice for those
+products. If such problems arise substantially in other domains, we
+stand ready to extend this provision to those domains in future versions
+of the GPL, as needed to protect the freedom of users.
+
+ Finally, every program is threatened constantly by software patents.
+States should not allow patents to restrict development and use of
+software on general-purpose computers, but in those that do, we wish to
+avoid the special danger that patents applied to a free program could
+make it effectively proprietary. To prevent this, the GPL assures that
+patents cannot be used to render the program non-free.
+
+ The precise terms and conditions for copying, distribution and
+modification follow.
+
+TERMS AND CONDITIONS
+====================
+
+ 0. Definitions.
+
+ “This License” refers to version 3 of the GNU General Public
+ License.
+
+ “Copyright” also means copyright-like laws that apply to other
+ kinds of works, such as semiconductor masks.
+
+ “The Program” refers to any copyrightable work licensed under this
+ License. Each licensee is addressed as “you”. “Licensees” and
+ “recipients” may be individuals or organizations.
+
+ To “modify” a work means to copy from or adapt all or part of the
+ work in a fashion requiring copyright permission, other than the
+ making of an exact copy. The resulting work is called a “modified
+ version” of the earlier work or a work “based on” the earlier work.
+
+ A “covered work” means either the unmodified Program or a work
+ based on the Program.
+
+ To “propagate” a work means to do anything with it that, without
+ permission, would make you directly or secondarily liable for
+ infringement under applicable copyright law, except executing it on
+ a computer or modifying a private copy. Propagation includes
+ copying, distribution (with or without modification), making
+ available to the public, and in some countries other activities as
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+ To “convey” a work means any kind of propagation that enables other
+ parties to make or receive copies. Mere interaction with a user
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+
+ An interactive user interface displays “Appropriate Legal Notices”
+ to the extent that it includes a convenient and prominently visible
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+ the extent that warranties are provided), that licensees may convey
+ the work under this License, and how to view a copy of this
+ License. If the interface presents a list of user commands or
+ options, such as a menu, a prominent item in the list meets this
+ criterion.
+
+ 1. Source Code.
+
+ The “source code” for a work means the preferred form of the work
+ for making modifications to it. “Object code” means any non-source
+ form of a work.
+
+ A “Standard Interface” means an interface that either is an
+ official standard defined by a recognized standards body, or, in
+ the case of interfaces specified for a particular programming
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+
+ The “System Libraries” of an executable work include anything,
+ other than the work as a whole, that (a) is included in the normal
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+ essential component (kernel, window system, and so on) of the
+ specific operating system (if any) on which the executable work
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+ The “Corresponding Source” for a work in object code form means all
+ the source code needed to generate, install, and (for an executable
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+
+ The Corresponding Source need not include anything that users can
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+ Source.
+
+ The Corresponding Source for a work in source code form is that
+ same work.
+
+ 2. Basic Permissions.
+
+ All rights granted under this License are granted for the term of
+ copyright on the Program, and are irrevocable provided the stated
+ conditions are met. This License explicitly affirms your unlimited
+ permission to run the unmodified Program. The output from running
+ a covered work is covered by this License only if the output, given
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+ your rights of fair use or other equivalent, as provided by
+ copyright law.
+
+ You may make, run and propagate covered works that you do not
+ convey, without conditions so long as your license otherwise
+ remains in force. You may convey covered works to others for the
+ sole purpose of having them make modifications exclusively for you,
+ or provide you with facilities for running those works, provided
+ that you comply with the terms of this License in conveying all
+ material for which you do not control copyright. Those thus making
+ or running the covered works for you must do so exclusively on your
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+ them from making any copies of your copyrighted material outside
+ their relationship with you.
+
+ Conveying under any other circumstances is permitted solely under
+ the conditions stated below. Sublicensing is not allowed; section
+ 10 makes it unnecessary.
+
+ 3. Protecting Users’ Legal Rights From Anti-Circumvention Law.
+
+ No covered work shall be deemed part of an effective technological
+ measure under any applicable law fulfilling obligations under
+ article 11 of the WIPO copyright treaty adopted on 20 December
+ 1996, or similar laws prohibiting or restricting circumvention of
+ such measures.
+
+ When you convey a covered work, you waive any legal power to forbid
+ circumvention of technological measures to the extent such
+ circumvention is effected by exercising rights under this License
+ with respect to the covered work, and you disclaim any intention to
+ limit operation or modification of the work as a means of
+ enforcing, against the work’s users, your or third parties’ legal
+ rights to forbid circumvention of technological measures.
+
+ 4. Conveying Verbatim Copies.
+
+ You may convey verbatim copies of the Program’s source code as you
+ receive it, in any medium, provided that you conspicuously and
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+ give all recipients a copy of this License along with the Program.
+
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+ modified it, and giving a relevant date.
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+ section 4 to “keep intact all notices”.
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+ public in source code form), and must require no special password
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+
+ 7. Additional Terms.
+
+ “Additional permissions” are terms that supplement the terms of
+ this License by making exceptions from one or more of its
+ conditions. Additional permissions that are applicable to the
+ entire Program shall be treated as though they were included in
+ this License, to the extent that they are valid under applicable
+ law. If additional permissions apply only to part of the Program,
+ that part may be used separately under those permissions, but the
+ entire Program remains governed by this License without regard to
+ the additional permissions.
+
+ When you convey a copy of a covered work, you may at your option
+ remove any additional permissions from that copy, or from any part
+ of it. (Additional permissions may be written to require their own
+ removal in certain cases when you modify the work.) You may place
+ additional permissions on material, added by you to a covered work,
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+ Notwithstanding any other provision of this License, for material
+ you add to a covered work, you may (if authorized by the copyright
+ holders of that material) supplement the terms of this License with
+ terms:
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+ a. Disclaiming warranty or limiting liability differently from
+ the terms of sections 15 and 16 of this License; or
+
+ b. Requiring preservation of specified reasonable legal notices
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+ Legal Notices displayed by works containing it; or
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+ c. Prohibiting misrepresentation of the origin of that material,
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+ material by anyone who conveys the material (or modified
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+ All other non-permissive additional terms are considered “further
+ restrictions” within the meaning of section 10. If the Program as
+ you received it, or any part of it, contains a notice stating that
+ it is governed by this License along with a term that is a further
+ restriction, you may remove that term. If a license document
+ contains a further restriction but permits relicensing or conveying
+ under this License, you may add to a covered work material governed
+ by the terms of that license document, provided that the further
+ restriction does not survive such relicensing or conveying.
+
+ If you add terms to a covered work in accord with this section, you
+ must place, in the relevant source files, a statement of the
+ additional terms that apply to those files, or a notice indicating
+ where to find the applicable terms.
+
+ Additional terms, permissive or non-permissive, may be stated in
+ the form of a separately written license, or stated as exceptions;
+ the above requirements apply either way.
+
+ 8. Termination.
+
+ You may not propagate or modify a covered work except as expressly
+ provided under this License. Any attempt otherwise to propagate or
+ modify it is void, and will automatically terminate your rights
+ under this License (including any patent licenses granted under the
+ third paragraph of section 11).
+
+ However, if you cease all violation of this License, then your
+ license from a particular copyright holder is reinstated (a)
+ provisionally, unless and until the copyright holder explicitly and
+ finally terminates your license, and (b) permanently, if the
+ copyright holder fails to notify you of the violation by some
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+ Moreover, your license from a particular copyright holder is
+ reinstated permanently if the copyright holder notifies you of the
+ violation by some reasonable means, this is the first time you have
+ received notice of violation of this License (for any work) from
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+ after your receipt of the notice.
+
+ Termination of your rights under this section does not terminate
+ the licenses of parties who have received copies or rights from you
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+ permanently reinstated, you do not qualify to receive new licenses
+ for the same material under section 10.
+
+ 9. Acceptance Not Required for Having Copies.
+
+ You are not required to accept this License in order to receive or
+ run a copy of the Program. Ancillary propagation of a covered work
+ occurring solely as a consequence of using peer-to-peer
+ transmission to receive a copy likewise does not require
+ acceptance. However, nothing other than this License grants you
+ permission to propagate or modify any covered work. These actions
+ infringe copyright if you do not accept this License. Therefore,
+ by modifying or propagating a covered work, you indicate your
+ acceptance of this License to do so.
+
+ 10. Automatic Licensing of Downstream Recipients.
+
+ Each time you convey a covered work, the recipient automatically
+ receives a license from the original licensors, to run, modify and
+ propagate that work, subject to this License. You are not
+ responsible for enforcing compliance by third parties with this
+ License.
+
+ An “entity transaction” is a transaction transferring control of an
+ organization, or substantially all assets of one, or subdividing an
+ organization, or merging organizations. If propagation of a
+ covered work results from an entity transaction, each party to that
+ transaction who receives a copy of the work also receives whatever
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+ of the Corresponding Source of the work from the predecessor in
+ interest, if the predecessor has it or can get it with reasonable
+ efforts.
+
+ You may not impose any further restrictions on the exercise of the
+ rights granted or affirmed under this License. For example, you
+ may not impose a license fee, royalty, or other charge for exercise
+ of rights granted under this License, and you may not initiate
+ litigation (including a cross-claim or counterclaim in a lawsuit)
+ alleging that any patent claim is infringed by making, using,
+ selling, offering for sale, or importing the Program or any portion
+ of it.
+
+ 11. Patents.
+
+ A “contributor” is a copyright holder who authorizes use under this
+ License of the Program or a work on which the Program is based.
+ The work thus licensed is called the contributor’s “contributor
+ version”.
+
+ A contributor’s “essential patent claims” are all patent claims
+ owned or controlled by the contributor, whether already acquired or
+ hereafter acquired, that would be infringed by some manner,
+ permitted by this License, of making, using, or selling its
+ contributor version, but do not include claims that would be
+ infringed only as a consequence of further modification of the
+ contributor version. For purposes of this definition, “control”
+ includes the right to grant patent sublicenses in a manner
+ consistent with the requirements of this License.
+
+ Each contributor grants you a non-exclusive, worldwide,
+ royalty-free patent license under the contributor’s essential
+ patent claims, to make, use, sell, offer for sale, import and
+ otherwise run, modify and propagate the contents of its contributor
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+ In the following three paragraphs, a “patent license” is any
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+ enforce a patent (such as an express permission to practice a
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+ such a patent license to a party means to make such an agreement or
+ commitment not to enforce a patent against the party.
+
+ If you convey a covered work, knowingly relying on a patent
+ license, and the Corresponding Source of the work is not available
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+ License, through a publicly available network server or other
+ readily accessible means, then you must either (1) cause the
+ Corresponding Source to be so available, or (2) arrange to deprive
+ yourself of the benefit of the patent license for this particular
+ work, or (3) arrange, in a manner consistent with the requirements
+ of this License, to extend the patent license to downstream
+ recipients. “Knowingly relying” means you have actual knowledge
+ that, but for the patent license, your conveying the covered work
+ in a country, or your recipient’s use of the covered work in a
+ country, would infringe one or more identifiable patents in that
+ country that you have reason to believe are valid.
+
+ If, pursuant to or in connection with a single transaction or
+ arrangement, you convey, or propagate by procuring conveyance of, a
+ covered work, and grant a patent license to some of the parties
+ receiving the covered work authorizing them to use, propagate,
+ modify or convey a specific copy of the covered work, then the
+ patent license you grant is automatically extended to all
+ recipients of the covered work and works based on it.
+
+ A patent license is “discriminatory” if it does not include within
+ the scope of its coverage, prohibits the exercise of, or is
+ conditioned on the non-exercise of one or more of the rights that
+ are specifically granted under this License. You may not convey a
+ covered work if you are a party to an arrangement with a third
+ party that is in the business of distributing software, under which
+ you make payment to the third party based on the extent of your
+ activity of conveying the work, and under which the third party
+ grants, to any of the parties who would receive the covered work
+ from you, a discriminatory patent license (a) in connection with
+ copies of the covered work conveyed by you (or copies made from
+ those copies), or (b) primarily for and in connection with specific
+ products or compilations that contain the covered work, unless you
+ entered into that arrangement, or that patent license was granted,
+ prior to 28 March 2007.
+
+ Nothing in this License shall be construed as excluding or limiting
+ any implied license or other defenses to infringement that may
+ otherwise be available to you under applicable patent law.
+
+ 12. No Surrender of Others’ Freedom.
+
+ If conditions are imposed on you (whether by court order, agreement
+ or otherwise) that contradict the conditions of this License, they
+ do not excuse you from the conditions of this License. If you
+ cannot convey a covered work so as to satisfy simultaneously your
+ obligations under this License and any other pertinent obligations,
+ then as a consequence you may not convey it at all. For example,
+ if you agree to terms that obligate you to collect a royalty for
+ further conveying from those to whom you convey the Program, the
+ only way you could satisfy both those terms and this License would
+ be to refrain entirely from conveying the Program.
+
+ 13. Use with the GNU Affero General Public License.
+
+ Notwithstanding any other provision of this License, you have
+ permission to link or combine any covered work with a work licensed
+ under version 3 of the GNU Affero General Public License into a
+ single combined work, and to convey the resulting work. The terms
+ of this License will continue to apply to the part which is the
+ covered work, but the special requirements of the GNU Affero
+ General Public License, section 13, concerning interaction through
+ a network will apply to the combination as such.
+
+ 14. Revised Versions of this License.
+
+ The Free Software Foundation may publish revised and/or new
+ versions of the GNU General Public License from time to time. Such
+ new versions will be similar in spirit to the present version, but
+ may differ in detail to address new problems or concerns.
+
+ Each version is given a distinguishing version number. If the
+ Program specifies that a certain numbered version of the GNU
+ General Public License “or any later version” applies to it, you
+ have the option of following the terms and conditions either of
+ that numbered version or of any later version published by the Free
+ Software Foundation. If the Program does not specify a version
+ number of the GNU General Public License, you may choose any
+ version ever published by the Free Software Foundation.
+
+ If the Program specifies that a proxy can decide which future
+ versions of the GNU General Public License can be used, that
+ proxy’s public statement of acceptance of a version permanently
+ authorizes you to choose that version for the Program.
+
+ Later license versions may give you additional or different
+ permissions. However, no additional obligations are imposed on any
+ author or copyright holder as a result of your choosing to follow a
+ later version.
+
+ 15. Disclaimer of Warranty.
+
+ THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+ APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE
+ COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM “AS IS”
+ WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED,
+ INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE
+ RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.
+ SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
+ NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+ 16. Limitation of Liability.
+
+ IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
+ WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES
+ AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR
+ DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR
+ CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
+ THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA
+ BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+ PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+ PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF
+ THE POSSIBILITY OF SUCH DAMAGES.
+
+ 17. Interpretation of Sections 15 and 16.
+
+ If the disclaimer of warranty and limitation of liability provided
+ above cannot be given local legal effect according to their terms,
+ reviewing courts shall apply local law that most closely
+ approximates an absolute waiver of all civil liability in
+ connection with the Program, unless a warranty or assumption of
+ liability accompanies a copy of the Program in return for a fee.
+
+END OF TERMS AND CONDITIONS
+===========================
+
+How to Apply These Terms to Your New Programs
+=============================================
+
+If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these
+terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least the
+“copyright” line and a pointer to where the full notice is found.
+
+ ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES.
+ Copyright (C) YEAR NAME OF AUTHOR
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or (at
+ your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+ Also add information on how to contact you by electronic and paper
+mail.
+
+ If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+ PROGRAM Copyright (C) YEAR NAME OF AUTHOR
+ This program comes with ABSOLUTELY NO WARRANTY; for details type ‘show w’.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type ‘show c’ for details.
+
+ The hypothetical commands ‘show w’ and ‘show c’ should show the
+appropriate parts of the General Public License. Of course, your
+program’s commands might be different; for a GUI interface, you would
+use an “about box”.
+
+ You should also get your employer (if you work as a programmer) or
+school, if any, to sign a “copyright disclaimer” for the program, if
+necessary. For more information on this, and how to apply and follow
+the GNU GPL, see <https://www.gnu.org/licenses/>.
+
+ The GNU General Public License does not permit incorporating your
+program into proprietary programs. If your program is a subroutine
+library, you may consider it more useful to permit linking proprietary
+applications with the library. If this is what you want to do, use the
+GNU Lesser General Public License instead of this License. But first,
+please read <https://www.gnu.org/licenses/why-not-lgpl.html>.
+
+
+File: dash.info, Node: Index, Prev: GPL, Up: Top
+
+Index
+*****
+
+
+* Menu:
+
+* !cdr: Destructive operations.
+ (line 16)
+* !cons: Destructive operations.
+ (line 8)
+* -->: Threading macros. (line 35)
+* ->: Threading macros. (line 9)
+* ->>: Threading macros. (line 22)
+* -all?: Predicates. (line 53)
+* -andfn: Function combinators.
+ (line 184)
+* -annotate: Maps. (line 86)
+* -any?: Predicates. (line 41)
+* -applify: Function combinators.
+ (line 63)
+* -as->: Threading macros. (line 49)
+* -butlast: Other list operations.
+ (line 335)
+* -clone: Tree operations. (line 123)
+* -common-prefix: Reductions. (line 242)
+* -common-suffix: Reductions. (line 252)
+* -compose: Function combinators.
+ (line 49)
+* -concat: List to list. (line 23)
+* -cons*: Other list operations.
+ (line 30)
+* -cons-pair?: Predicates. (line 167)
+* -const: Function combinators.
+ (line 128)
+* -contains?: Predicates. (line 100)
+* -copy: Maps. (line 141)
+* -count: Reductions. (line 172)
+* -cut: Function combinators.
+ (line 140)
+* -cycle: Other list operations.
+ (line 180)
+* -difference: Set operations. (line 20)
+* -distinct: Set operations. (line 62)
+* -dotimes: Side effects. (line 80)
+* -doto: Threading macros. (line 99)
+* -drop: Sublist selection. (line 149)
+* -drop-last: Sublist selection. (line 163)
+* -drop-while: Sublist selection. (line 194)
+* -each: Side effects. (line 8)
+* -each-indexed: Side effects. (line 38)
+* -each-r: Side effects. (line 52)
+* -each-r-while: Side effects. (line 65)
+* -each-while: Side effects. (line 24)
+* -elem-index: Indexing. (line 9)
+* -elem-indices: Indexing. (line 21)
+* -every: Predicates. (line 23)
+* -fifth-item: Other list operations.
+ (line 315)
+* -filter: Sublist selection. (line 8)
+* -find-index: Indexing. (line 32)
+* -find-indices: Indexing. (line 60)
+* -find-last-index: Indexing. (line 46)
+* -first: Other list operations.
+ (line 246)
+* -first-item: Other list operations.
+ (line 272)
+* -fix: Other list operations.
+ (line 375)
+* -fixfn: Function combinators.
+ (line 224)
+* -flatten: List to list. (line 36)
+* -flatten-n: List to list. (line 58)
+* -flip: Function combinators.
+ (line 95)
+* -fourth-item: Other list operations.
+ (line 305)
+* -grade-down: Indexing. (line 81)
+* -grade-up: Indexing. (line 71)
+* -group-by: Partitioning. (line 205)
+* -if-let: Binding. (line 34)
+* -if-let*: Binding. (line 45)
+* -inits: Reductions. (line 222)
+* -insert-at: List to list. (line 112)
+* -interleave: Other list operations.
+ (line 67)
+* -interpose: Other list operations.
+ (line 57)
+* -intersection: Set operations. (line 32)
+* -iota: Other list operations.
+ (line 78)
+* -is-infix?: Predicates. (line 153)
+* -is-prefix?: Predicates. (line 129)
+* -is-suffix?: Predicates. (line 141)
+* -iterate: Unfolding. (line 9)
+* -iteratefn: Function combinators.
+ (line 201)
+* -juxt: Function combinators.
+ (line 37)
+* -keep: List to list. (line 8)
+* -lambda: Binding. (line 247)
+* -last: Other list operations.
+ (line 262)
+* -last-item: Other list operations.
+ (line 325)
+* -let: Binding. (line 61)
+* -let*: Binding. (line 227)
+* -list: Other list operations.
+ (line 358)
+* -map: Maps. (line 10)
+* -map-first: Maps. (line 38)
+* -map-indexed: Maps. (line 68)
+* -map-last: Maps. (line 53)
+* -map-when: Maps. (line 22)
+* -mapcat: Maps. (line 130)
+* -max: Reductions. (line 286)
+* -max-by: Reductions. (line 296)
+* -min: Reductions. (line 262)
+* -min-by: Reductions. (line 272)
+* -non-nil: Sublist selection. (line 95)
+* -none?: Predicates. (line 73)
+* -not: Function combinators.
+ (line 153)
+* -on: Function combinators.
+ (line 75)
+* -only-some?: Predicates. (line 85)
+* -orfn: Function combinators.
+ (line 167)
+* -pad: Other list operations.
+ (line 191)
+* -partial: Function combinators.
+ (line 8)
+* -partition: Partitioning. (line 90)
+* -partition-after-item: Partitioning. (line 195)
+* -partition-after-pred: Partitioning. (line 162)
+* -partition-all: Partitioning. (line 102)
+* -partition-all-in-steps: Partitioning. (line 126)
+* -partition-before-item: Partitioning. (line 185)
+* -partition-before-pred: Partitioning. (line 174)
+* -partition-by: Partitioning. (line 138)
+* -partition-by-header: Partitioning. (line 149)
+* -partition-in-steps: Partitioning. (line 113)
+* -permutations: Set operations. (line 52)
+* -powerset: Set operations. (line 44)
+* -prodfn: Function combinators.
+ (line 258)
+* -product: Reductions. (line 201)
+* -reduce: Reductions. (line 53)
+* -reduce-from: Reductions. (line 8)
+* -reduce-r: Reductions. (line 72)
+* -reduce-r-from: Reductions. (line 26)
+* -reductions: Reductions. (line 136)
+* -reductions-from: Reductions. (line 100)
+* -reductions-r: Reductions. (line 154)
+* -reductions-r-from: Reductions. (line 118)
+* -remove: Sublist selection. (line 26)
+* -remove-at: List to list. (line 149)
+* -remove-at-indices: List to list. (line 162)
+* -remove-first: Sublist selection. (line 44)
+* -remove-item: Sublist selection. (line 84)
+* -remove-last: Sublist selection. (line 65)
+* -repeat: Other list operations.
+ (line 19)
+* -replace: List to list. (line 70)
+* -replace-at: List to list. (line 123)
+* -replace-first: List to list. (line 84)
+* -replace-last: List to list. (line 98)
+* -rotate: Other list operations.
+ (line 8)
+* -rotate-args: Function combinators.
+ (line 112)
+* -rpartial: Function combinators.
+ (line 22)
+* -running-product: Reductions. (line 211)
+* -running-sum: Reductions. (line 190)
+* -same-items?: Predicates. (line 115)
+* -second-item: Other list operations.
+ (line 285)
+* -select-by-indices: Sublist selection. (line 211)
+* -select-column: Sublist selection. (line 241)
+* -select-columns: Sublist selection. (line 222)
+* -separate: Partitioning. (line 75)
+* -setq: Binding. (line 270)
+* -slice: Sublist selection. (line 105)
+* -snoc: Other list operations.
+ (line 43)
+* -some: Predicates. (line 8)
+* -some-->: Threading macros. (line 86)
+* -some->: Threading macros. (line 62)
+* -some->>: Threading macros. (line 74)
+* -sort: Other list operations.
+ (line 345)
+* -splice: Maps. (line 97)
+* -splice-list: Maps. (line 117)
+* -split-at: Partitioning. (line 8)
+* -split-on: Partitioning. (line 40)
+* -split-when: Partitioning. (line 58)
+* -split-with: Partitioning. (line 23)
+* -sum: Reductions. (line 180)
+* -table: Other list operations.
+ (line 202)
+* -table-flat: Other list operations.
+ (line 221)
+* -tails: Reductions. (line 232)
+* -take: Sublist selection. (line 121)
+* -take-last: Sublist selection. (line 135)
+* -take-while: Sublist selection. (line 177)
+* -third-item: Other list operations.
+ (line 295)
+* -tree-map: Tree operations. (line 28)
+* -tree-map-nodes: Tree operations. (line 39)
+* -tree-mapreduce: Tree operations. (line 85)
+* -tree-mapreduce-from: Tree operations. (line 104)
+* -tree-reduce: Tree operations. (line 53)
+* -tree-reduce-from: Tree operations. (line 70)
+* -tree-seq: Tree operations. (line 8)
+* -unfold: Unfolding. (line 25)
+* -union: Set operations. (line 8)
+* -unzip: Other list operations.
+ (line 158)
+* -update-at: List to list. (line 135)
+* -when-let: Binding. (line 9)
+* -when-let*: Binding. (line 21)
+* -zip: Other list operations.
+ (line 107)
+* -zip-fill: Other list operations.
+ (line 150)
+* -zip-lists: Other list operations.
+ (line 131)
+* -zip-with: Other list operations.
+ (line 91)
+* dash-fontify-mode: Fontification of special variables.
+ (line 6)
+* dash-register-info-lookup: Info symbol lookup. (line 6)
+* global-dash-fontify-mode: Fontification of special variables.
+ (line 12)
+
+
+
+Tag Table:
+Node: Top742
+Node: Installation2397
+Node: Using in a package3159
+Node: Fontification of special variables3504
+Node: Info symbol lookup4294
+Node: Functions4877
+Node: Maps6361
+Ref: -map6658
+Ref: -map-when7031
+Ref: -map-first7605
+Ref: -map-last8200
+Ref: -map-indexed8790
+Ref: -annotate9476
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+Ref: -splice-list10741
+Ref: -mapcat11200
+Ref: -copy11573
+Node: Sublist selection11761
+Ref: -filter11954
+Ref: -remove12507
+Ref: -remove-first13056
+Ref: -remove-last13904
+Ref: -remove-item14634
+Ref: -non-nil15034
+Ref: -slice15316
+Ref: -take15845
+Ref: -take-last16263
+Ref: -drop16700
+Ref: -drop-last17147
+Ref: -take-while17579
+Ref: -drop-while18206
+Ref: -select-by-indices18839
+Ref: -select-columns19350
+Ref: -select-column20053
+Node: List to list20516
+Ref: -keep20708
+Ref: -concat21284
+Ref: -flatten21767
+Ref: -flatten-n22529
+Ref: -replace22913
+Ref: -replace-first23374
+Ref: -replace-last23869
+Ref: -insert-at24357
+Ref: -replace-at24682
+Ref: -update-at25069
+Ref: -remove-at25610
+Ref: -remove-at-indices26095
+Node: Reductions26674
+Ref: -reduce-from26870
+Ref: -reduce-r-from27594
+Ref: -reduce28857
+Ref: -reduce-r29608
+Ref: -reductions-from30886
+Ref: -reductions-r-from31692
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+Ref: -common-prefix35755
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+Ref: -min-by36569
+Ref: -max37090
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+Node: Unfolding37841
+Ref: -iterate38082
+Ref: -unfold38529
+Node: Predicates39334
+Ref: -some39511
+Ref: -every39940
+Ref: -any?40654
+Ref: -all?41003
+Ref: -none?41745
+Ref: -only-some?42065
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+Ref: -is-prefix?43396
+Ref: -is-suffix?43728
+Ref: -is-infix?44060
+Ref: -cons-pair?44420
+Node: Partitioning44751
+Ref: -split-at44939
+Ref: -split-with45603
+Ref: -split-on46243
+Ref: -split-when46914
+Ref: -separate47557
+Ref: -partition48091
+Ref: -partition-all48540
+Ref: -partition-in-steps48965
+Ref: -partition-all-in-steps49511
+Ref: -partition-by50025
+Ref: -partition-by-header50403
+Ref: -partition-after-pred51004
+Ref: -partition-before-pred51457
+Ref: -partition-before-item51842
+Ref: -partition-after-item52149
+Ref: -group-by52451
+Node: Indexing52884
+Ref: -elem-index53086
+Ref: -elem-indices53487
+Ref: -find-index53867
+Ref: -find-last-index54362
+Ref: -find-indices54872
+Ref: -grade-up55277
+Ref: -grade-down55684
+Node: Set operations56098
+Ref: -union56281
+Ref: -difference56695
+Ref: -intersection57113
+Ref: -powerset57526
+Ref: -permutations57736
+Ref: -distinct58032
+Node: Other list operations58412
+Ref: -rotate58637
+Ref: -repeat58990
+Ref: -cons*59275
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+Ref: -interpose60109
+Ref: -interleave60403
+Ref: -iota60769
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+Ref: -unzip63815
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+Ref: -fifth-item69125
+Ref: -last-item69393
+Ref: -butlast69690
+Ref: -sort69935
+Ref: -list70427
+Ref: -fix70996
+Node: Tree operations71485
+Ref: -tree-seq71681
+Ref: -tree-map72542
+Ref: -tree-map-nodes72982
+Ref: -tree-reduce73846
+Ref: -tree-reduce-from74728
+Ref: -tree-mapreduce75328
+Ref: -tree-mapreduce-from76187
+Ref: -clone77472
+Node: Threading macros77799
+Ref: ->78024
+Ref: ->>78512
+Ref: -->79015
+Ref: -as->79571
+Ref: -some->80025
+Ref: -some->>80410
+Ref: -some-->80857
+Ref: -doto81424
+Node: Binding81977
+Ref: -when-let82184
+Ref: -when-let*82645
+Ref: -if-let83174
+Ref: -if-let*83540
+Ref: -let84163
+Ref: -let*90253
+Ref: -lambda91190
+Ref: -setq91996
+Node: Side effects92797
+Ref: -each92991
+Ref: -each-while93518
+Ref: -each-indexed94138
+Ref: -each-r94730
+Ref: -each-r-while95172
+Ref: -dotimes95816
+Node: Destructive operations96369
+Ref: !cons96587
+Ref: !cdr96791
+Node: Function combinators96984
+Ref: -partial97188
+Ref: -rpartial97706
+Ref: -juxt98354
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+Ref: -on99843
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+Node: Development108151
+Node: Contribute108440
+Node: Contributors109452
+Node: FDL111545
+Node: GPL136865
+Node: Index174614
+
+End Tag Table
+
+
+Local Variables:
+coding: utf-8
+End: