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diff --git a/configs/shared/emacs/.emacs.d/elpa/dash-20180413.30/dash.el b/configs/shared/emacs/.emacs.d/elpa/dash-20180413.30/dash.el new file mode 100644 index 000000000000..c0553497bac5 --- /dev/null +++ b/configs/shared/emacs/.emacs.d/elpa/dash-20180413.30/dash.el @@ -0,0 +1,2800 @@ +;;; dash.el --- A modern list library for Emacs -*- lexical-binding: t -*- + +;; Copyright (C) 2012-2016 Free Software Foundation, Inc. + +;; Author: Magnar Sveen <magnars@gmail.com> +;; Version: 2.14.1 +;; Package-Version: 20180413.30 +;; Keywords: lists + +;; 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 <http://www.gnu.org/licenses/>. + +;;; Commentary: + +;; A modern list api for Emacs. +;; +;; See documentation on https://github.com/magnars/dash.el#functions +;; +;; **Please note** The lexical binding in this file is not utilised at the +;; moment. We will take full advantage of lexical binding in an upcoming 3.0 +;; release of Dash. In the meantime, we've added the pragma to avoid a bug that +;; you can read more about in https://github.com/magnars/dash.el/issues/130. +;; + +;;; Code: + +(defgroup dash () + "Customize group for dash.el" + :group 'lisp + :prefix "dash-") + +(defun dash--enable-fontlock (symbol value) + (when value + (dash-enable-font-lock)) + (set-default symbol value)) + +(defcustom dash-enable-fontlock nil + "If non-nil, enable fontification of dash functions, macros and +special values." + :type 'boolean + :set 'dash--enable-fontlock + :group 'dash) + +(defmacro !cons (car cdr) + "Destructive: Set CDR to the cons of CAR and CDR." + `(setq ,cdr (cons ,car ,cdr))) + +(defmacro !cdr (list) + "Destructive: Set LIST to the cdr of LIST." + `(setq ,list (cdr ,list))) + +(defmacro --each (list &rest body) + "Anaphoric form of `-each'." + (declare (debug (form body)) + (indent 1)) + (let ((l (make-symbol "list"))) + `(let ((,l ,list) + (it-index 0)) + (while ,l + (let ((it (car ,l))) + ,@body) + (setq it-index (1+ it-index)) + (!cdr ,l))))) + +(defmacro -doto (eval-initial-value &rest forms) + "Eval a form, then insert that form as the 2nd argument to other forms. +The EVAL-INITIAL-VALUE form is evaluated once. Its result is +passed to FORMS, which are then evaluated sequentially. Returns +the target form." + (declare (indent 1)) + (let ((retval (make-symbol "value"))) + `(let ((,retval ,eval-initial-value)) + ,@(mapcar (lambda (form) + (if (sequencep form) + `(,(-first-item form) ,retval ,@(cdr form)) + `(funcall form ,retval))) + forms) + ,retval))) + +(defun -each (list fn) + "Call FN with every item in LIST. Return nil, used for side-effects only." + (--each list (funcall fn it))) + +(put '-each 'lisp-indent-function 1) + +(defalias '--each-indexed '--each) + +(defun -each-indexed (list fn) + "Call (FN index item) for each item in LIST. + +In the anaphoric form `--each-indexed', the index is exposed as symbol `it-index'. + +See also: `-map-indexed'." + (--each list (funcall fn it-index it))) +(put '-each-indexed 'lisp-indent-function 1) + +(defmacro --each-while (list pred &rest body) + "Anaphoric form of `-each-while'." + (declare (debug (form form body)) + (indent 2)) + (let ((l (make-symbol "list")) + (c (make-symbol "continue"))) + `(let ((,l ,list) + (,c t) + (it-index 0)) + (while (and ,l ,c) + (let ((it (car ,l))) + (if (not ,pred) (setq ,c nil) ,@body)) + (setq it-index (1+ it-index)) + (!cdr ,l))))) + +(defun -each-while (list pred fn) + "Call FN with every item in LIST while (PRED item) is non-nil. +Return nil, used for side-effects only." + (--each-while list (funcall pred it) (funcall fn it))) + +(put '-each-while 'lisp-indent-function 2) + +(defmacro --dotimes (num &rest body) + "Repeatedly executes BODY (presumably for side-effects) with symbol `it' bound to integers from 0 through NUM-1." + (declare (debug (form body)) + (indent 1)) + (let ((n (make-symbol "num"))) + `(let ((,n ,num) + (it 0)) + (while (< it ,n) + ,@body + (setq it (1+ it)))))) + +(defun -dotimes (num fn) + "Repeatedly calls FN (presumably for side-effects) passing in integers from 0 through NUM-1." + (--dotimes num (funcall fn it))) + +(put '-dotimes 'lisp-indent-function 1) + +(defun -map (fn list) + "Return a new list consisting of the result of applying FN to the items in LIST." + (mapcar fn list)) + +(defmacro --map (form list) + "Anaphoric form of `-map'." + (declare (debug (form form))) + `(mapcar (lambda (it) ,form) ,list)) + +(defmacro --reduce-from (form initial-value list) + "Anaphoric form of `-reduce-from'." + (declare (debug (form form form))) + `(let ((acc ,initial-value)) + (--each ,list (setq acc ,form)) + acc)) + +(defun -reduce-from (fn initial-value list) + "Return the result of applying FN to INITIAL-VALUE and the +first item in LIST, then applying FN to that result and the 2nd +item, etc. If LIST contains no items, return INITIAL-VALUE and +FN is not called. + +In the anaphoric form `--reduce-from', the accumulated value is +exposed as symbol `acc'. + +See also: `-reduce', `-reduce-r'" + (--reduce-from (funcall fn acc it) initial-value list)) + +(defmacro --reduce (form list) + "Anaphoric form of `-reduce'." + (declare (debug (form form))) + (let ((lv (make-symbol "list-value"))) + `(let ((,lv ,list)) + (if ,lv + (--reduce-from ,form (car ,lv) (cdr ,lv)) + (let (acc it) ,form))))) + +(defun -reduce (fn list) + "Return the result of applying FN to the first 2 items in LIST, +then applying FN to that result and the 3rd item, etc. If LIST +contains no items, FN must accept no arguments as well, and +reduce return the result of calling FN with no arguments. If +LIST has only 1 item, it is returned and FN is not called. + +In the anaphoric form `--reduce', the accumulated value is +exposed as symbol `acc'. + +See also: `-reduce-from', `-reduce-r'" + (if list + (-reduce-from fn (car list) (cdr list)) + (funcall fn))) + +(defun -reduce-r-from (fn initial-value list) + "Replace conses with FN, nil with INITIAL-VALUE and evaluate +the resulting expression. If LIST is empty, INITIAL-VALUE is +returned and FN is not called. + +Note: this function works the same as `-reduce-from' but the +operation associates from right instead of from left. + +See also: `-reduce-r', `-reduce'" + (if (not list) initial-value + (funcall fn (car list) (-reduce-r-from fn initial-value (cdr list))))) + +(defmacro --reduce-r-from (form initial-value list) + "Anaphoric version of `-reduce-r-from'." + (declare (debug (form form form))) + `(-reduce-r-from (lambda (&optional it acc) ,form) ,initial-value ,list)) + +(defun -reduce-r (fn list) + "Replace conses with FN and evaluate the resulting expression. +The final nil is ignored. If LIST contains no items, FN must +accept no arguments as well, and reduce return the result of +calling FN with no arguments. If LIST has only 1 item, it is +returned and FN is not called. + +The first argument of FN is the new item, the second is the +accumulated value. + +Note: this function works the same as `-reduce' but the operation +associates from right instead of from left. + +See also: `-reduce-r-from', `-reduce'" + (cond + ((not list) (funcall fn)) + ((not (cdr list)) (car list)) + (t (funcall fn (car list) (-reduce-r fn (cdr list)))))) + +(defmacro --reduce-r (form list) + "Anaphoric version of `-reduce-r'." + (declare (debug (form form))) + `(-reduce-r (lambda (&optional it acc) ,form) ,list)) + +(defun -reductions-from (fn init list) + "Return a list of the intermediate values of the reduction. + +See `-reduce-from' for explanation of the arguments. + +See also: `-reductions', `-reductions-r', `-reduce-r'" + (nreverse (--reduce-from (cons (funcall fn (car acc) it) acc) (list init) list))) + +(defun -reductions (fn list) + "Return a list of the intermediate values of the reduction. + +See `-reduce' for explanation of the arguments. + +See also: `-reductions-from', `-reductions-r', `-reduce-r'" + (-reductions-from fn (car list) (cdr list))) + +(defun -reductions-r-from (fn init list) + "Return a list of the intermediate values of the reduction. + +See `-reduce-r-from' for explanation of the arguments. + +See also: `-reductions-r', `-reductions', `-reduce'" + (--reduce-r-from (cons (funcall fn it (car acc)) acc) (list init) list)) + +(defun -reductions-r (fn list) + "Return a list of the intermediate values of the reduction. + +See `-reduce-r' for explanation of the arguments. + +See also: `-reductions-r-from', `-reductions', `-reduce'" + (-reductions-r-from fn (-last-item list) (-butlast list))) + +(defmacro --filter (form list) + "Anaphoric form of `-filter'. + +See also: `--remove'." + (declare (debug (form form))) + (let ((r (make-symbol "result"))) + `(let (,r) + (--each ,list (when ,form (!cons it ,r))) + (nreverse ,r)))) + +(defun -filter (pred list) + "Return a new list of the items in LIST for which PRED returns a non-nil value. + +Alias: `-select' + +See also: `-keep', `-remove'." + (--filter (funcall pred it) list)) + +(defalias '-select '-filter) +(defalias '--select '--filter) + +(defmacro --remove (form list) + "Anaphoric form of `-remove'. + +See also `--filter'." + (declare (debug (form form))) + `(--filter (not ,form) ,list)) + +(defun -remove (pred list) + "Return a new list of the items in LIST for which PRED returns nil. + +Alias: `-reject' + +See also: `-filter'." + (--remove (funcall pred it) list)) + +(defalias '-reject '-remove) +(defalias '--reject '--remove) + +(defun -remove-first (pred list) + "Return a new list with the first item matching PRED removed. + +Alias: `-reject-first' + +See also: `-remove', `-map-first'" + (let (front) + (while (and list (not (funcall pred (car list)))) + (push (car list) front) + (!cdr list)) + (if list + (-concat (nreverse front) (cdr list)) + (nreverse front)))) + +(defmacro --remove-first (form list) + "Anaphoric form of `-remove-first'." + (declare (debug (form form))) + `(-remove-first (lambda (it) ,form) ,list)) + +(defalias '-reject-first '-remove-first) +(defalias '--reject-first '--remove-first) + +(defun -remove-last (pred list) + "Return a new list with the last item matching PRED removed. + +Alias: `-reject-last' + +See also: `-remove', `-map-last'" + (nreverse (-remove-first pred (reverse list)))) + +(defmacro --remove-last (form list) + "Anaphoric form of `-remove-last'." + (declare (debug (form form))) + `(-remove-last (lambda (it) ,form) ,list)) + +(defalias '-reject-last '-remove-last) +(defalias '--reject-last '--remove-last) + +(defun -remove-item (item list) + "Remove all occurences of ITEM from LIST. + +Comparison is done with `equal'." + (declare (pure t) (side-effect-free t)) + (--remove (equal it item) list)) + +(defmacro --keep (form list) + "Anaphoric form of `-keep'." + (declare (debug (form form))) + (let ((r (make-symbol "result")) + (m (make-symbol "mapped"))) + `(let (,r) + (--each ,list (let ((,m ,form)) (when ,m (!cons ,m ,r)))) + (nreverse ,r)))) + +(defun -keep (fn list) + "Return a new list of the non-nil results of applying FN to the items in LIST. + +If you want to select the original items satisfying a predicate use `-filter'." + (--keep (funcall fn it) list)) + +(defun -non-nil (list) + "Return all non-nil elements of LIST." + (declare (pure t) (side-effect-free t)) + (-remove 'null list)) + +(defmacro --map-indexed (form list) + "Anaphoric form of `-map-indexed'." + (declare (debug (form form))) + (let ((r (make-symbol "result"))) + `(let (,r) + (--each ,list + (!cons ,form ,r)) + (nreverse ,r)))) + +(defun -map-indexed (fn list) + "Return a new list consisting of the result of (FN index item) for each item in LIST. + +In the anaphoric form `--map-indexed', the index is exposed as symbol `it-index'. + +See also: `-each-indexed'." + (--map-indexed (funcall fn it-index it) list)) + +(defmacro --map-when (pred rep list) + "Anaphoric form of `-map-when'." + (declare (debug (form form form))) + (let ((r (make-symbol "result"))) + `(let (,r) + (--each ,list (!cons (if ,pred ,rep it) ,r)) + (nreverse ,r)))) + +(defun -map-when (pred rep list) + "Return a new list where the elements in LIST that do not match the PRED function +are unchanged, and where the elements in LIST that do match the PRED function are mapped +through the REP function. + +Alias: `-replace-where' + +See also: `-update-at'" + (--map-when (funcall pred it) (funcall rep it) list)) + +(defalias '-replace-where '-map-when) +(defalias '--replace-where '--map-when) + +(defun -map-first (pred rep list) + "Replace first item in LIST satisfying PRED with result of REP called on this item. + +See also: `-map-when', `-replace-first'" + (let (front) + (while (and list (not (funcall pred (car list)))) + (push (car list) front) + (!cdr list)) + (if list + (-concat (nreverse front) (cons (funcall rep (car list)) (cdr list))) + (nreverse front)))) + +(defmacro --map-first (pred rep list) + "Anaphoric form of `-map-first'." + `(-map-first (lambda (it) ,pred) (lambda (it) (ignore it) ,rep) ,list)) + +(defun -map-last (pred rep list) + "Replace last item in LIST satisfying PRED with result of REP called on this item. + +See also: `-map-when', `-replace-last'" + (nreverse (-map-first pred rep (reverse list)))) + +(defmacro --map-last (pred rep list) + "Anaphoric form of `-map-last'." + `(-map-last (lambda (it) ,pred) (lambda (it) (ignore it) ,rep) ,list)) + +(defun -replace (old new list) + "Replace all OLD items in LIST with NEW. + +Elements are compared using `equal'. + +See also: `-replace-at'" + (declare (pure t) (side-effect-free t)) + (--map-when (equal it old) new list)) + +(defun -replace-first (old new list) + "Replace the first occurence of OLD with NEW in LIST. + +Elements are compared using `equal'. + +See also: `-map-first'" + (declare (pure t) (side-effect-free t)) + (--map-first (equal old it) new list)) + +(defun -replace-last (old new list) + "Replace the last occurence of OLD with NEW in LIST. + +Elements are compared using `equal'. + +See also: `-map-last'" + (declare (pure t) (side-effect-free t)) + (--map-last (equal old it) new list)) + +(defmacro --mapcat (form list) + "Anaphoric form of `-mapcat'." + (declare (debug (form form))) + `(apply 'append (--map ,form ,list))) + +(defun -mapcat (fn list) + "Return the concatenation of the result of mapping FN over LIST. +Thus function FN should return a list." + (--mapcat (funcall fn it) list)) + +(defun -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' +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'" + (declare (pure t) (side-effect-free t)) + (if (and (listp l) (listp (cdr l))) + (-mapcat '-flatten l) + (list l))) + +(defmacro --iterate (form init n) + "Anaphoric version of `-iterate'." + (declare (debug (form form form))) + `(-iterate (lambda (it) ,form) ,init ,n)) + +(defun -flatten-n (num list) + "Flatten NUM levels of a nested LIST. + +See also: `-flatten'" + (declare (pure t) (side-effect-free t)) + (-last-item (--iterate (--mapcat (-list it) it) list (1+ num)))) + +(defun -concat (&rest lists) + "Return a new list with the concatenation of the elements in the supplied LISTS." + (declare (pure t) (side-effect-free t)) + (apply 'append lists)) + +(defalias '-copy 'copy-sequence + "Create a shallow copy of LIST. + +\(fn LIST)") + +(defun -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', `-insert-at'" + (let (r) + (--each list + (if (funcall pred it) + (let ((new (funcall fun it))) + (--each new (!cons it r))) + (!cons it r))) + (nreverse r))) + +(defmacro --splice (pred form list) + "Anaphoric form of `-splice'." + `(-splice (lambda (it) ,pred) (lambda (it) ,form) ,list)) + +(defun -splice-list (pred new-list list) + "Splice NEW-LIST in place of elements matching PRED in LIST. + +See also: `-splice', `-insert-at'" + (-splice pred (lambda (_) new-list) list)) + +(defmacro --splice-list (pred new-list list) + "Anaphoric form of `-splice-list'." + `(-splice-list (lambda (it) ,pred) ,new-list ,list)) + +(defun -cons* (&rest args) + "Make a new list from the elements of ARGS. + +The last 2 members of ARGS are used as the final cons of the +result so if the final member of ARGS is not a list the result is +a dotted list." + (declare (pure t) (side-effect-free t)) + (-reduce-r 'cons args)) + +(defun -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 ELEMENTS is non nil, append these to the list as well." + (-concat list (list elem) elements)) + +(defmacro --first (form list) + "Anaphoric form of `-first'." + (declare (debug (form form))) + (let ((n (make-symbol "needle"))) + `(let (,n) + (--each-while ,list (not ,n) + (when ,form (setq ,n it))) + ,n))) + +(defun -first (pred list) + "Return the first x in LIST where (PRED x) is non-nil, else nil. + +To get the first item in the list no questions asked, use `car'. + +Alias: `-find'" + (--first (funcall pred it) list)) + +(defalias '-find '-first) +(defalias '--find '--first) + +(defmacro --some (form list) + "Anaphoric form of `-some'." + (declare (debug (form form))) + (let ((n (make-symbol "needle"))) + `(let (,n) + (--each-while ,list (not ,n) + (setq ,n ,form)) + ,n))) + +(defun -some (pred list) + "Return (PRED x) for the first LIST item where (PRED x) is non-nil, else nil. + +Alias: `-any'" + (--some (funcall pred it) list)) + +(defalias '-any '-some) +(defalias '--any '--some) + +(defmacro --last (form list) + "Anaphoric form of `-last'." + (declare (debug (form form))) + (let ((n (make-symbol "needle"))) + `(let (,n) + (--each ,list + (when ,form (setq ,n it))) + ,n))) + +(defun -last (pred list) + "Return the last x in LIST where (PRED x) is non-nil, else nil." + (--last (funcall pred it) list)) + +(defalias '-first-item 'car + "Return the first item of LIST, or nil on an empty list. + +See also: `-second-item', `-last-item'. + +\(fn LIST)") + +;; Ensure that calls to `-first-item' are compiled to a single opcode, +;; just like `car'. +(put '-first-item 'byte-opcode 'byte-car) +(put '-first-item 'byte-compile 'byte-compile-one-arg) + +(defalias '-second-item 'cadr + "Return the second item of LIST, or nil if LIST is too short. + +See also: `-third-item'. + +\(fn LIST)") + +(defalias '-third-item 'caddr + "Return the third item of LIST, or nil if LIST is too short. + +See also: `-fourth-item'. + +\(fn LIST)") + +(defun -fourth-item (list) + "Return the fourth item of LIST, or nil if LIST is too short. + +See also: `-fifth-item'." + (declare (pure t) (side-effect-free t)) + (car (cdr (cdr (cdr list))))) + +(defun -fifth-item (list) + "Return the fifth item of LIST, or nil if LIST is too short. + +See also: `-last-item'." + (declare (pure t) (side-effect-free t)) + (car (cdr (cdr (cdr (cdr list)))))) + +;; TODO: gv was introduced in 24.3, so we can remove the if statement +;; when support for earlier versions is dropped +(eval-when-compile + (require 'cl) + (if (fboundp 'gv-define-simple-setter) + (gv-define-simple-setter -first-item setcar) + (require 'cl) + (with-no-warnings + (defsetf -first-item (x) (val) `(setcar ,x ,val))))) + +(defun -last-item (list) + "Return the last item of LIST, or nil on an empty list." + (declare (pure t) (side-effect-free t)) + (car (last list))) + +;; TODO: gv was introduced in 24.3, so we can remove the if statement +;; when support for earlier versions is dropped +(eval-when-compile + (if (fboundp 'gv-define-setter) + (gv-define-setter -last-item (val x) `(setcar (last ,x) ,val)) + (with-no-warnings + (defsetf -last-item (x) (val) `(setcar (last ,x) ,val))))) + +(defun -butlast (list) + "Return a list of all items in list except for the last." + ;; no alias as we don't want magic optional argument + (declare (pure t) (side-effect-free t)) + (butlast list)) + +(defmacro --count (pred list) + "Anaphoric form of `-count'." + (declare (debug (form form))) + (let ((r (make-symbol "result"))) + `(let ((,r 0)) + (--each ,list (when ,pred (setq ,r (1+ ,r)))) + ,r))) + +(defun -count (pred list) + "Counts the number of items in LIST where (PRED item) is non-nil." + (--count (funcall pred it) list)) + +(defun ---truthy? (val) + (declare (pure t) (side-effect-free t)) + (not (null val))) + +(defmacro --any? (form list) + "Anaphoric form of `-any?'." + (declare (debug (form form))) + `(---truthy? (--some ,form ,list))) + +(defun -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? (funcall pred it) list)) + +(defalias '-some? '-any?) +(defalias '--some? '--any?) +(defalias '-any-p '-any?) +(defalias '--any-p '--any?) +(defalias '-some-p '-any?) +(defalias '--some-p '--any?) + +(defmacro --all? (form list) + "Anaphoric form of `-all?'." + (declare (debug (form form))) + (let ((a (make-symbol "all"))) + `(let ((,a t)) + (--each-while ,list ,a (setq ,a ,form)) + (---truthy? ,a)))) + +(defun -all? (pred list) + "Return t if (PRED x) is non-nil for all x in LIST, else nil. + +Alias: `-all-p', `-every?', `-every-p'" + (--all? (funcall pred it) list)) + +(defalias '-every? '-all?) +(defalias '--every? '--all?) +(defalias '-all-p '-all?) +(defalias '--all-p '--all?) +(defalias '-every-p '-all?) +(defalias '--every-p '--all?) + +(defmacro --none? (form list) + "Anaphoric form of `-none?'." + (declare (debug (form form))) + `(--all? (not ,form) ,list)) + +(defun -none? (pred list) + "Return t if (PRED x) is nil for all x in LIST, else nil. + +Alias: `-none-p'" + (--none? (funcall pred it) list)) + +(defalias '-none-p '-none?) +(defalias '--none-p '--none?) + +(defmacro --only-some? (form list) + "Anaphoric form of `-only-some?'." + (declare (debug (form form))) + (let ((y (make-symbol "yes")) + (n (make-symbol "no"))) + `(let (,y ,n) + (--each-while ,list (not (and ,y ,n)) + (if ,form (setq ,y t) (setq ,n t))) + (---truthy? (and ,y ,n))))) + +(defun -only-some? (pred list) + "Return `t` if at least one item of LIST matches PRED and at least one item of LIST does not match PRED. +Return `nil` both if all items match the predicate or if none of the items match the predicate. + +Alias: `-only-some-p'" + (--only-some? (funcall pred it) list)) + +(defalias '-only-some-p '-only-some?) +(defalias '--only-some-p '--only-some?) + +(defun -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." + (declare (pure t) (side-effect-free t)) + (let ((length (length list)) + (new-list nil)) + ;; to defaults to the end of the list + (setq to (or to length)) + (setq step (or step 1)) + ;; handle negative indices + (when (< from 0) + (setq from (mod from length))) + (when (< to 0) + (setq to (mod to length))) + + ;; iterate through the list, keeping the elements we want + (--each-while list (< it-index to) + (when (and (>= it-index from) + (= (mod (- from it-index) step) 0)) + (push it new-list))) + (nreverse new-list))) + +(defun -take (n list) + "Return a new list of the first N items in LIST, or all items if there are fewer than N. + +See also: `-take-last'" + (declare (pure t) (side-effect-free t)) + (let (result) + (--dotimes n + (when list + (!cons (car list) result) + (!cdr list))) + (nreverse result))) + +(defun -take-last (n list) + "Return the last N items of LIST in order. + +See also: `-take'" + (declare (pure t) (side-effect-free t)) + (copy-sequence (last list n))) + +(defalias '-drop 'nthcdr + "Return the tail of LIST without the first N items. + +See also: `-drop-last' + +\(fn N LIST)") + +(defun -drop-last (n list) + "Remove the last N items of LIST and return a copy. + +See also: `-drop'" + ;; No alias because we don't want magic optional argument + (declare (pure t) (side-effect-free t)) + (butlast list n)) + +(defmacro --take-while (form list) + "Anaphoric form of `-take-while'." + (declare (debug (form form))) + (let ((r (make-symbol "result"))) + `(let (,r) + (--each-while ,list ,form (!cons it ,r)) + (nreverse ,r)))) + +(defun -take-while (pred list) + "Return a new list of successive items from LIST while (PRED item) returns a non-nil value." + (--take-while (funcall pred it) list)) + +(defmacro --drop-while (form list) + "Anaphoric form of `-drop-while'." + (declare (debug (form form))) + (let ((l (make-symbol "list"))) + `(let ((,l ,list)) + (while (and ,l (let ((it (car ,l))) ,form)) + (!cdr ,l)) + ,l))) + +(defun -drop-while (pred list) + "Return the tail of LIST starting from the first item for which (PRED item) returns nil." + (--drop-while (funcall pred it) list)) + +(defun -split-at (n list) + "Return a list of ((-take N LIST) (-drop N LIST)), in no more than one pass through the list." + (declare (pure t) (side-effect-free t)) + (let (result) + (--dotimes n + (when list + (!cons (car list) result) + (!cdr list))) + (list (nreverse result) list))) + +(defun -rotate (n list) + "Rotate LIST N places to the right. With N negative, rotate to the left. +The time complexity is O(n)." + (declare (pure t) (side-effect-free t)) + (if (> n 0) + (append (last list n) (butlast list n)) + (append (-drop (- n) list) (-take (- n) list)))) + +(defun -insert-at (n x list) + "Return a list with X inserted into LIST at position N. + +See also: `-splice', `-splice-list'" + (declare (pure t) (side-effect-free t)) + (let ((split-list (-split-at n list))) + (nconc (car split-list) (cons x (cadr split-list))))) + +(defun -replace-at (n x list) + "Return a list with element at Nth position in LIST replaced with X. + +See also: `-replace'" + (declare (pure t) (side-effect-free t)) + (let ((split-list (-split-at n list))) + (nconc (car split-list) (cons x (cdr (cadr split-list)))))) + +(defun -update-at (n func list) + "Return a list with element at Nth position in LIST replaced with `(func (nth n list))`. + +See also: `-map-when'" + (let ((split-list (-split-at n list))) + (nconc (car split-list) (cons (funcall func (car (cadr split-list))) (cdr (cadr split-list)))))) + +(defmacro --update-at (n form list) + "Anaphoric version of `-update-at'." + (declare (debug (form form form))) + `(-update-at ,n (lambda (it) ,form) ,list)) + +(defun -remove-at (n list) + "Return a list with element at Nth position in LIST removed. + +See also: `-remove-at-indices', `-remove'" + (declare (pure t) (side-effect-free t)) + (-remove-at-indices (list n) list)) + +(defun -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', `-remove'" + (declare (pure t) (side-effect-free t)) + (let* ((indices (-sort '< indices)) + (diffs (cons (car indices) (-map '1- (-zip-with '- (cdr indices) indices)))) + r) + (--each diffs + (let ((split (-split-at it list))) + (!cons (car split) r) + (setq list (cdr (cadr split))))) + (!cons list r) + (apply '-concat (nreverse r)))) + +(defmacro --split-with (pred list) + "Anaphoric form of `-split-with'." + (declare (debug (form form))) + (let ((l (make-symbol "list")) + (r (make-symbol "result")) + (c (make-symbol "continue"))) + `(let ((,l ,list) + (,r nil) + (,c t)) + (while (and ,l ,c) + (let ((it (car ,l))) + (if (not ,pred) + (setq ,c nil) + (!cons it ,r) + (!cdr ,l)))) + (list (nreverse ,r) ,l)))) + +(defun -split-with (pred list) + "Return a list of ((-take-while PRED LIST) (-drop-while PRED LIST)), in no more than one pass through the list." + (--split-with (funcall pred it) list)) + +(defmacro -split-on (item list) + "Split the LIST each time ITEM is found. + +Unlike `-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'" + (declare (debug (form form))) + `(-split-when (lambda (it) (equal it ,item)) ,list)) + +(defmacro --split-when (form list) + "Anaphoric version of `-split-when'." + (declare (debug (form form))) + `(-split-when (lambda (it) ,form) ,list)) + +(defun -split-when (fn list) + "Split the LIST on each element where FN returns non-nil. + +Unlike `-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'." + (let (r s) + (while list + (if (not (funcall fn (car list))) + (push (car list) s) + (when s (push (nreverse s) r)) + (setq s nil)) + (!cdr list)) + (when s (push (nreverse s) r)) + (nreverse r))) + +(defmacro --separate (form list) + "Anaphoric form of `-separate'." + (declare (debug (form form))) + (let ((y (make-symbol "yes")) + (n (make-symbol "no"))) + `(let (,y ,n) + (--each ,list (if ,form (!cons it ,y) (!cons it ,n))) + (list (nreverse ,y) (nreverse ,n))))) + +(defun -separate (pred list) + "Return a list of ((-filter PRED LIST) (-remove PRED LIST)), in one pass through the list." + (--separate (funcall pred it) list)) + +(defun ---partition-all-in-steps-reversed (n step list) + "Private: Used by -partition-all-in-steps and -partition-in-steps." + (when (< step 1) + (error "Step must be a positive number, or you're looking at some juicy infinite loops.")) + (let ((result nil)) + (while list + (!cons (-take n list) result) + (setq list (-drop step list))) + result)) + +(defun -partition-all-in-steps (n step list) + "Return a new list with the items in LIST grouped into N-sized sublists at offsets STEP apart. +The last groups may contain less than N items." + (declare (pure t) (side-effect-free t)) + (nreverse (---partition-all-in-steps-reversed n step list))) + +(defun -partition-in-steps (n step list) + "Return a new list with the items in LIST grouped into N-sized sublists at offsets STEP apart. +If there are not enough items to make the last group N-sized, +those items are discarded." + (declare (pure t) (side-effect-free t)) + (let ((result (---partition-all-in-steps-reversed n step list))) + (while (and result (< (length (car result)) n)) + (!cdr result)) + (nreverse result))) + +(defun -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." + (declare (pure t) (side-effect-free t)) + (-partition-all-in-steps n n list)) + +(defun -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." + (declare (pure t) (side-effect-free t)) + (-partition-in-steps n n list)) + +(defmacro --partition-by (form list) + "Anaphoric form of `-partition-by'." + (declare (debug (form form))) + (let ((r (make-symbol "result")) + (s (make-symbol "sublist")) + (v (make-symbol "value")) + (n (make-symbol "new-value")) + (l (make-symbol "list"))) + `(let ((,l ,list)) + (when ,l + (let* ((,r nil) + (it (car ,l)) + (,s (list it)) + (,v ,form) + (,l (cdr ,l))) + (while ,l + (let* ((it (car ,l)) + (,n ,form)) + (unless (equal ,v ,n) + (!cons (nreverse ,s) ,r) + (setq ,s nil) + (setq ,v ,n)) + (!cons it ,s) + (!cdr ,l))) + (!cons (nreverse ,s) ,r) + (nreverse ,r)))))) + +(defun -partition-by (fn list) + "Apply FN to each item in LIST, splitting it each time FN returns a new value." + (--partition-by (funcall fn it) list)) + +(defmacro --partition-by-header (form list) + "Anaphoric form of `-partition-by-header'." + (declare (debug (form form))) + (let ((r (make-symbol "result")) + (s (make-symbol "sublist")) + (h (make-symbol "header-value")) + (b (make-symbol "seen-body?")) + (n (make-symbol "new-value")) + (l (make-symbol "list"))) + `(let ((,l ,list)) + (when ,l + (let* ((,r nil) + (it (car ,l)) + (,s (list it)) + (,h ,form) + (,b nil) + (,l (cdr ,l))) + (while ,l + (let* ((it (car ,l)) + (,n ,form)) + (if (equal ,h ,n) + (when ,b + (!cons (nreverse ,s) ,r) + (setq ,s nil) + (setq ,b nil)) + (setq ,b t)) + (!cons it ,s) + (!cdr ,l))) + (!cons (nreverse ,s) ,r) + (nreverse ,r)))))) + +(defun -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 (funcall fn it) list)) + +(defun -partition-after-pred (pred list) + "Partition directly after each time PRED is true on an element of LIST." + (when list + (let ((rest (-partition-after-pred pred + (cdr list)))) + (if (funcall pred (car list)) + ;;split after (car list) + (cons (list (car list)) + rest) + + ;;don't split after (car list) + (cons (cons (car list) + (car rest)) + (cdr rest)))))) + +(defun -partition-before-pred (pred list) + "Partition directly before each time PRED is true on an element of LIST." + (nreverse (-map #'reverse + (-partition-after-pred pred (reverse list))))) + +(defun -partition-after-item (item list) + "Partition directly after each time ITEM appears in LIST." + (-partition-after-pred (lambda (ele) (equal ele item)) + list)) + +(defun -partition-before-item (item list) + "Partition directly before each time ITEM appears in LIST." + (-partition-before-pred (lambda (ele) (equal ele item)) + list)) + +(defmacro --group-by (form list) + "Anaphoric form of `-group-by'." + (declare (debug t)) + (let ((n (make-symbol "n")) + (k (make-symbol "k")) + (grp (make-symbol "grp"))) + `(nreverse + (-map + (lambda (,n) + (cons (car ,n) + (nreverse (cdr ,n)))) + (--reduce-from + (let* ((,k (,@form)) + (,grp (assoc ,k acc))) + (if ,grp + (setcdr ,grp (cons it (cdr ,grp))) + (push + (list ,k it) + acc)) + acc) + nil ,list))))) + +(defun -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 (funcall fn it) list)) + +(defun -interpose (sep list) + "Return a new list of all elements in LIST separated by SEP." + (declare (pure t) (side-effect-free t)) + (let (result) + (when list + (!cons (car list) result) + (!cdr list)) + (while list + (setq result (cons (car list) (cons sep result))) + (!cdr list)) + (nreverse result))) + +(defun -interleave (&rest lists) + "Return a new list of the first item in each list, then the second etc." + (declare (pure t) (side-effect-free t)) + (when lists + (let (result) + (while (-none? 'null lists) + (--each lists (!cons (car it) result)) + (setq lists (-map 'cdr lists))) + (nreverse result)))) + +(defmacro --zip-with (form list1 list2) + "Anaphoric form of `-zip-with'. + +The elements in list1 are bound as symbol `it', the elements in list2 as symbol `other'." + (declare (debug (form form form))) + (let ((r (make-symbol "result")) + (l1 (make-symbol "list1")) + (l2 (make-symbol "list2"))) + `(let ((,r nil) + (,l1 ,list1) + (,l2 ,list2)) + (while (and ,l1 ,l2) + (let ((it (car ,l1)) + (other (car ,l2))) + (!cons ,form ,r) + (!cdr ,l1) + (!cdr ,l2))) + (nreverse ,r)))) + +(defun -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 (funcall fn it other) list1 list2)) + +(defun -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. + +Please note! This distinction is being removed in an upcoming 3.0 +release of Dash. If you rely on this behavior, use -zip-pair instead." + (declare (pure t) (side-effect-free t)) + (when lists + (let (results) + (while (-none? 'null lists) + (setq results (cons (mapcar 'car lists) results)) + (setq lists (mapcar 'cdr lists))) + (setq results (nreverse results)) + (if (= (length lists) 2) + ;; to support backward compatability, return + ;; a cons cell if two lists were provided + (--map (cons (car it) (cadr it)) results) + results)))) + +(defalias '-zip-pair '-zip) + +(defun -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." + (declare (pure t) (side-effect-free t)) + (apply '-zip (apply '-pad (cons fill-value lists)))) + +(defun -unzip (lists) + "Unzip LISTS. + +This works just like `-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). + +See also: `-zip'" + (apply '-zip lists)) + +(defun -cycle (list) + "Return an infinite copy of LIST that will cycle through the +elements and repeat from the beginning." + (declare (pure t) (side-effect-free t)) + (let ((newlist (-map 'identity list))) + (nconc newlist newlist))) + +(defun -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." + (let* ((annotations (-annotate 'length lists)) + (n (-max (-map 'car annotations)))) + (--map (append (cdr it) (-repeat (- n (car it)) fill-value)) annotations))) + +(defun -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." + (-zip (-map fn list) list)) + +(defmacro --annotate (form list) + "Anaphoric version of `-annotate'." + (declare (debug (form form))) + `(-annotate (lambda (it) ,form) ,list)) + +(defun dash--table-carry (lists restore-lists &optional re) + "Helper for `-table' and `-table-flat'. + +If a list overflows, carry to the right and reset the list." + (while (not (or (car lists) + (equal lists '(nil)))) + (setcar lists (car restore-lists)) + (pop (cadr lists)) + (!cdr lists) + (!cdr restore-lists) + (when re + (push (nreverse (car re)) (cadr re)) + (setcar re nil) + (!cdr re)))) + +(defun -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'" + (let ((restore-lists (copy-sequence lists)) + (last-list (last lists)) + (re (make-list (length lists) nil))) + (while (car last-list) + (let ((item (apply fn (-map 'car lists)))) + (push item (car re)) + (setcar lists (cdar lists)) ;; silence byte compiler + (dash--table-carry lists restore-lists re))) + (nreverse (car (last re))))) + +(defun -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', `-table'" + (let ((restore-lists (copy-sequence lists)) + (last-list (last lists)) + re) + (while (car last-list) + (let ((item (apply fn (-map 'car lists)))) + (push item re) + (setcar lists (cdar lists)) ;; silence byte compiler + (dash--table-carry lists restore-lists))) + (nreverse re))) + +(defun -partial (fn &rest args) + "Take a function FN and fewer than the normal arguments to FN, +and return a fn that takes a variable number of additional ARGS. +When called, the returned function calls FN with ARGS first and +then additional args." + (apply 'apply-partially fn args)) + +(defun -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." + (declare (pure t) (side-effect-free t)) + (car (-elem-indices elem list))) + +(defun -elem-indices (elem list) + "Return the indices of all elements in LIST equal to the query +element ELEM, in ascending order." + (declare (pure t) (side-effect-free t)) + (-find-indices (-partial 'equal elem) list)) + +(defun -find-indices (pred list) + "Return the indices of all elements in LIST satisfying the +predicate PRED, in ascending order." + (apply 'append (--map-indexed (when (funcall pred it) (list it-index)) list))) + +(defmacro --find-indices (form list) + "Anaphoric version of `-find-indices'." + (declare (debug (form form))) + `(-find-indices (lambda (it) ,form) ,list)) + +(defun -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'." + (car (-find-indices pred list))) + +(defmacro --find-index (form list) + "Anaphoric version of `-find-index'." + (declare (debug (form form))) + `(-find-index (lambda (it) ,form) ,list)) + +(defun -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'." + (-last-item (-find-indices pred list))) + +(defmacro --find-last-index (form list) + "Anaphoric version of `-find-last-index'." + `(-find-last-index (lambda (it) ,form) ,list)) + +(defun -select-by-indices (indices list) + "Return a list whose elements are elements from LIST selected +as `(nth i list)` for all i from INDICES." + (declare (pure t) (side-effect-free t)) + (let (r) + (--each indices + (!cons (nth it list) r)) + (nreverse r))) + +(defun -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', `-select-by-indices'" + (declare (pure t) (side-effect-free t)) + (--map (-select-by-indices columns it) table)) + +(defun -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', `-select-by-indices'" + (declare (pure t) (side-effect-free t)) + (--mapcat (-select-by-indices (list column) it) table)) + +(defmacro -> (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." + (declare (debug (form &rest [&or symbolp (sexp &rest form)]))) + (cond + ((null form) x) + ((null more) (if (listp form) + `(,(car form) ,x ,@(cdr form)) + (list form x))) + (:else `(-> (-> ,x ,form) ,@more)))) + +(defmacro ->> (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." + (declare (debug ->)) + (cond + ((null form) x) + ((null more) (if (listp form) + `(,@form ,x) + (list form x))) + (:else `(->> (->> ,x ,form) ,@more)))) + +(defmacro --> (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." + (declare (debug (form body))) + `(-as-> ,x it ,@forms)) + +(defmacro -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." + (declare (debug (form symbolp body))) + (if (null forms) + `,value + `(let ((,variable ,value)) + (-as-> ,(if (symbolp (car forms)) + (list (car forms) variable) + (car forms)) + ,variable + ,@(cdr forms))))) + +(defmacro -some-> (x &optional form &rest more) + "When expr is non-nil, thread it through the first form (via `->'), +and when that result is non-nil, through the next form, etc." + (declare (debug ->)) + (if (null form) x + (let ((result (make-symbol "result"))) + `(-some-> (-when-let (,result ,x) + (-> ,result ,form)) + ,@more)))) + +(defmacro -some->> (x &optional form &rest more) + "When expr is non-nil, thread it through the first form (via `->>'), +and when that result is non-nil, through the next form, etc." + (declare (debug ->)) + (if (null form) x + (let ((result (make-symbol "result"))) + `(-some->> (-when-let (,result ,x) + (->> ,result ,form)) + ,@more)))) + +(defmacro -some--> (x &optional form &rest more) + "When expr in non-nil, thread it through the first form (via `-->'), +and when that result is non-nil, through the next form, etc." + (declare (debug ->)) + (if (null form) x + (let ((result (make-symbol "result"))) + `(-some--> (-when-let (,result ,x) + (--> ,result ,form)) + ,@more)))) + +(defun -grade-up (comparator list) + "Grade elements of LIST using COMPARATOR relation, yielding a +permutation vector such that applying this permutation to LIST +sorts it in ascending order." + ;; ugly hack to "fix" lack of lexical scope + (let ((comp `(lambda (it other) (funcall ',comparator (car it) (car other))))) + (->> (--map-indexed (cons it it-index) list) + (-sort comp) + (-map 'cdr)))) + +(defun -grade-down (comparator list) + "Grade elements of LIST using COMPARATOR relation, yielding a +permutation vector such that applying this permutation to LIST +sorts it in descending order." + ;; ugly hack to "fix" lack of lexical scope + (let ((comp `(lambda (it other) (funcall ',comparator (car other) (car it))))) + (->> (--map-indexed (cons it it-index) list) + (-sort comp) + (-map 'cdr)))) + +(defvar dash--source-counter 0 + "Monotonic counter for generated symbols.") + +(defun dash--match-make-source-symbol () + "Generate a new dash-source symbol. + +All returned symbols are guaranteed to be unique." + (prog1 (make-symbol (format "--dash-source-%d--" dash--source-counter)) + (setq dash--source-counter (1+ dash--source-counter)))) + +(defun dash--match-ignore-place-p (symbol) + "Return non-nil if SYMBOL is a symbol and starts with _." + (and (symbolp symbol) + (eq (aref (symbol-name symbol) 0) ?_))) + +(defun dash--match-cons-skip-cdr (skip-cdr source) + "Helper function generating idiomatic shifting code." + (cond + ((= skip-cdr 0) + `(pop ,source)) + (t + `(prog1 ,(dash--match-cons-get-car skip-cdr source) + (setq ,source ,(dash--match-cons-get-cdr (1+ skip-cdr) source)))))) + +(defun dash--match-cons-get-car (skip-cdr source) + "Helper function generating idiomatic code to get nth car." + (cond + ((= skip-cdr 0) + `(car ,source)) + ((= skip-cdr 1) + `(cadr ,source)) + (t + `(nth ,skip-cdr ,source)))) + +(defun dash--match-cons-get-cdr (skip-cdr source) + "Helper function generating idiomatic code to get nth cdr." + (cond + ((= skip-cdr 0) + source) + ((= skip-cdr 1) + `(cdr ,source)) + (t + `(nthcdr ,skip-cdr ,source)))) + +(defun dash--match-cons (match-form source) + "Setup a cons matching environment and call the real matcher." + (let ((s (dash--match-make-source-symbol)) + (n 0) + (m match-form)) + (while (and (consp m) + (dash--match-ignore-place-p (car m))) + (setq n (1+ n)) (!cdr m)) + (cond + ;; when we only have one pattern in the list, we don't have to + ;; create a temporary binding (--dash-source--) for the source + ;; and just use the input directly + ((and (consp m) + (not (cdr m))) + (dash--match (car m) (dash--match-cons-get-car n source))) + ;; handle other special types + ((> n 0) + (dash--match m (dash--match-cons-get-cdr n source))) + ;; this is the only entry-point for dash--match-cons-1, that's + ;; why we can't simply use the above branch, it would produce + ;; infinite recursion + (t + (cons (list s source) (dash--match-cons-1 match-form s)))))) + +(defun dash--match-cons-1 (match-form source &optional props) + "Match MATCH-FORM against SOURCE. + +MATCH-FORM is a proper or improper list. Each element of +MATCH-FORM is either a symbol, which gets bound to the respective +value in source or another match form which gets destructured +recursively. + +If the cdr of last cons cell in the list is `nil', matching stops +there. + +SOURCE is a proper or improper list." + (let ((skip-cdr (or (plist-get props :skip-cdr) 0))) + (cond + ((consp match-form) + (cond + ((cdr match-form) + (cond + ((and (symbolp (car match-form)) + (memq (car match-form) '(&keys &plist &alist &hash))) + (dash--match-kv match-form (dash--match-cons-get-cdr skip-cdr source))) + ((dash--match-ignore-place-p (car match-form)) + (dash--match-cons-1 (cdr match-form) source + (plist-put props :skip-cdr (1+ skip-cdr)))) + (t + (-concat (dash--match (car match-form) (dash--match-cons-skip-cdr skip-cdr source)) + (dash--match-cons-1 (cdr match-form) source))))) + (t ;; Last matching place, no need for shift + (dash--match (car match-form) (dash--match-cons-get-car skip-cdr source))))) + ((eq match-form nil) + nil) + (t ;; Handle improper lists. Last matching place, no need for shift + (dash--match match-form (dash--match-cons-get-cdr skip-cdr source)))))) + +(defun dash--vector-tail (seq start) + "Return the tail of SEQ starting at START." + (cond + ((vectorp seq) + (let* ((re-length (- (length seq) start)) + (re (make-vector re-length 0))) + (--dotimes re-length (aset re it (aref seq (+ it start)))) + re)) + ((stringp seq) + (substring seq start)))) + +(defun dash--match-vector (match-form source) + "Setup a vector matching environment and call the real matcher." + (let ((s (dash--match-make-source-symbol))) + (cond + ;; don't bind `s' if we only have one sub-pattern + ((= (length match-form) 1) + (dash--match (aref match-form 0) `(aref ,source 0))) + ;; if the source is a symbol, we don't need to re-bind it + ((symbolp source) + (dash--match-vector-1 match-form source)) + ;; don't bind `s' if we only have one sub-pattern which is not ignored + ((let* ((ignored-places (mapcar 'dash--match-ignore-place-p match-form)) + (ignored-places-n (length (-remove 'null ignored-places)))) + (when (= ignored-places-n (1- (length match-form))) + (let ((n (-find-index 'null ignored-places))) + (dash--match (aref match-form n) `(aref ,source ,n)))))) + (t + (cons (list s source) (dash--match-vector-1 match-form s)))))) + +(defun dash--match-vector-1 (match-form source) + "Match MATCH-FORM against SOURCE. + +MATCH-FORM is a vector. Each element of MATCH-FORM is either a +symbol, which gets bound to the respective value in source or +another match form which gets destructured recursively. + +If second-from-last place in MATCH-FORM is the symbol &rest, the +next element of the MATCH-FORM is matched against the tail of +SOURCE, starting at index of the &rest symbol. This is +conceptually the same as the (head . tail) match for improper +lists, where dot plays the role of &rest. + +SOURCE is a vector. + +If the MATCH-FORM vector is shorter than SOURCE vector, only +the (length MATCH-FORM) places are bound, the rest of the SOURCE +is discarded." + (let ((i 0) + (l (length match-form)) + (re)) + (while (< i l) + (let ((m (aref match-form i))) + (push (cond + ((and (symbolp m) + (eq m '&rest)) + (prog1 (dash--match + (aref match-form (1+ i)) + `(dash--vector-tail ,source ,i)) + (setq i l))) + ((and (symbolp m) + ;; do not match symbols starting with _ + (not (eq (aref (symbol-name m) 0) ?_))) + (list (list m `(aref ,source ,i)))) + ((not (symbolp m)) + (dash--match m `(aref ,source ,i)))) + re) + (setq i (1+ i)))) + (-flatten-n 1 (nreverse re)))) + +(defun dash--match-kv (match-form source) + "Setup a kv matching environment and call the real matcher. + +kv can be any key-value store, such as plist, alist or hash-table." + (let ((s (dash--match-make-source-symbol))) + (cond + ;; don't bind `s' if we only have one sub-pattern (&type key val) + ((= (length match-form) 3) + (dash--match-kv-1 (cdr match-form) source (car match-form))) + ;; if the source is a symbol, we don't need to re-bind it + ((symbolp source) + (dash--match-kv-1 (cdr match-form) source (car match-form))) + (t + (cons (list s source) (dash--match-kv-1 (cdr match-form) s (car match-form))))))) + +(defun dash--match-kv-1 (match-form source type) + "Match MATCH-FORM against SOURCE of type TYPE. + +MATCH-FORM is a proper list of the form (key1 place1 ... keyN +placeN). Each placeK is either a symbol, which gets bound to the +value of keyK retrieved from the key-value store, or another +match form which gets destructured recursively. + +SOURCE is a key-value store of type TYPE, which can be a plist, +an alist or a hash table. + +TYPE is a token specifying the type of the key-value store. +Valid values are &plist, &alist and &hash." + (-flatten-n 1 (-map + (lambda (kv) + (let* ((k (car kv)) + (v (cadr kv)) + (getter (cond + ((or (eq type '&plist) (eq type '&keys)) + `(plist-get ,source ,k)) + ((eq type '&alist) + `(cdr (assoc ,k ,source))) + ((eq type '&hash) + `(gethash ,k ,source))))) + (cond + ((symbolp v) + (list (list v getter))) + (t (dash--match v getter))))) + (-partition 2 match-form)))) + +(defun dash--match-symbol (match-form source) + "Bind a symbol. + +This works just like `let', there is no destructuring." + (list (list match-form source))) + +(defun dash--match (match-form source) + "Match MATCH-FORM against SOURCE. + +This function tests the MATCH-FORM and dispatches to specific +matchers based on the type of the expression. + +Key-value stores are disambiguated by placing a token &plist, +&alist or &hash as a first item in the MATCH-FORM." + (cond + ((symbolp match-form) + (dash--match-symbol match-form source)) + ((consp match-form) + (cond + ;; Handle the "x &as" bindings first. + ((and (consp (cdr match-form)) + (symbolp (car match-form)) + (eq '&as (cadr match-form))) + (let ((s (car match-form))) + (cons (list s source) + (dash--match (cddr match-form) s)))) + ((memq (car match-form) '(&keys &plist &alist &hash)) + (dash--match-kv match-form source)) + (t (dash--match-cons match-form source)))) + ((vectorp match-form) + ;; We support the &as binding in vectors too + (cond + ((and (> (length match-form) 2) + (symbolp (aref match-form 0)) + (eq '&as (aref match-form 1))) + (let ((s (aref match-form 0))) + (cons (list s source) + (dash--match (dash--vector-tail match-form 2) s)))) + (t (dash--match-vector match-form source)))))) + +(defmacro -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' for the list of all possible patterns." + (declare (debug ((&rest (sexp form)) body)) + (indent 1)) + (let ((bindings (--mapcat (dash--match (car it) (cadr it)) varlist))) + `(let* ,bindings + ,@body))) + +(defmacro -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' 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. + + (&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. + + (&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. + +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). + +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." + (declare (debug ([&or (&rest (sexp form)) + (vector [&rest [sexp form]])] + body)) + (indent 1)) + (if (vectorp varlist) + `(let* ,(dash--match (aref varlist 0) (aref varlist 1)) + ,@body) + (let* ((inputs (--map-indexed (list (make-symbol (format "input%d" it-index)) (cadr it)) varlist)) + (new-varlist (--map (list (caar it) (cadr it)) (-zip varlist inputs)))) + `(let ,inputs + (-let* ,new-varlist ,@body))))) + +(defmacro -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' for the description of destructuring mechanism." + (declare (doc-string 2) (indent defun) + (debug (&define sexp + [&optional stringp] + [&optional ("interactive" interactive)] + def-body))) + (cond + ((not (consp match-form)) + (signal 'wrong-type-argument "match-form must be a list")) + ;; no destructuring, so just return regular lambda to make things faster + ((-all? 'symbolp match-form) + `(lambda ,match-form ,@body)) + (t + (let* ((inputs (--map-indexed (list it (make-symbol (format "input%d" it-index))) match-form))) + ;; TODO: because inputs to the lambda are evaluated only once, + ;; -let* need not to create the extra bindings to ensure that. + ;; We should find a way to optimize that. Not critical however. + `(lambda ,(--map (cadr it) inputs) + (-let* ,inputs ,@body)))))) + +(defmacro -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*'. VALS are evaluated +sequentially, and evaluation stops after the first nil VAL is +encountered." + (declare (debug ((&rest (sexp form)) form body)) + (indent 2)) + (->> vars-vals + (--mapcat (dash--match (car it) (cadr it))) + (--reduce-r-from + (let ((var (car it)) + (val (cadr it))) + `(let ((,var ,val)) + (if ,var ,acc ,@else))) + then))) + +(defmacro -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'. + +\(fn (VAR VAL) THEN &rest ELSE)" + (declare (debug ((sexp form) form body)) + (indent 2)) + `(-if-let* (,var-val) ,then ,@else)) + +(defmacro --if-let (val then &rest else) + "If VAL evaluates to non-nil, bind it to symbol `it' and do THEN, +otherwise do ELSE." + (declare (debug (form form body)) + (indent 2)) + `(-if-let (it ,val) ,then ,@else)) + +(defmacro -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*'. VALS are evaluated +sequentially, and evaluation stops after the first nil VAL is +encountered." + (declare (debug ((&rest (sexp form)) body)) + (indent 1)) + `(-if-let* ,vars-vals (progn ,@body))) + +(defmacro -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'. + +\(fn (VAR VAL) &rest BODY)" + (declare (debug ((sexp form) body)) + (indent 1)) + `(-if-let ,var-val (progn ,@body))) + +(defmacro --when-let (val &rest body) + "If VAL evaluates to non-nil, bind it to symbol `it' and +execute body." + (declare (debug (form body)) + (indent 1)) + `(--if-let ,val (progn ,@body))) + +(defvar -compare-fn nil + "Tests for equality use this function or `equal' if this is nil. +It should only be set using dynamic scope with a let, like: + + (let ((-compare-fn #\\='=)) (-union numbers1 numbers2 numbers3)") + +(defun -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'" + (let (result) + (--each list (unless (-contains? result it) (!cons it result))) + (nreverse result))) + +(defalias '-uniq '-distinct) + +(defun -union (list list2) + "Return a new list containing the elements of LIST and elements of LIST2 that are not in LIST. +The test for equality is done with `equal', +or with `-compare-fn' if that's non-nil." + ;; We fall back to iteration implementation if the comparison + ;; function isn't one of `eq', `eql' or `equal'. + (let* ((result (reverse list)) + ;; TODO: get rid of this dynamic variable, pass it as an + ;; argument instead. + (-compare-fn (if (bound-and-true-p -compare-fn) + -compare-fn + 'equal))) + (if (memq -compare-fn '(eq eql equal)) + (let ((ht (make-hash-table :test -compare-fn))) + (--each list (puthash it t ht)) + (--each list2 (unless (gethash it ht) (!cons it result)))) + (--each list2 (unless (-contains? result it) (!cons it result)))) + (nreverse result))) + +(defun -intersection (list list2) + "Return a new list containing only the elements that are members of both LIST and LIST2. +The test for equality is done with `equal', +or with `-compare-fn' if that's non-nil." + (--filter (-contains? list2 it) list)) + +(defun -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." + (--filter (not (-contains? list2 it)) list)) + +(defun -powerset (list) + "Return the power set of LIST." + (if (null list) '(()) + (let ((last (-powerset (cdr list)))) + (append (mapcar (lambda (x) (cons (car list) x)) last) + last)))) + +(defun -permutations (list) + "Return the permutations of LIST." + (if (null list) '(()) + (apply #'append + (mapcar (lambda (x) + (mapcar (lambda (perm) (cons x perm)) + (-permutations (remove x list)))) + list)))) + +(defun -inits (list) + "Return all prefixes of LIST." + (nreverse (-map 'reverse (-tails (nreverse list))))) + +(defun -tails (list) + "Return all suffixes of LIST" + (-reductions-r-from 'cons nil list)) + +(defun -common-prefix (&rest lists) + "Return the longest common prefix of LISTS." + (declare (pure t) (side-effect-free t)) + (--reduce (--take-while (and acc (equal (pop acc) it)) it) + lists)) + +(defun -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'" + (not + (null + (cond + ((null -compare-fn) (member element list)) + ((eq -compare-fn 'eq) (memq element list)) + ((eq -compare-fn 'eql) (memql element list)) + (t + (let ((lst list)) + (while (and lst + (not (funcall -compare-fn element (car lst)))) + (setq lst (cdr lst))) + lst)))))) + +(defalias '-contains-p '-contains?) + +(defun -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'" + (let ((length-a (length list)) + (length-b (length list2))) + (and + (= length-a length-b) + (= length-a (length (-intersection list list2)))))) + +(defalias '-same-items-p '-same-items?) + +(defun -is-prefix? (prefix list) + "Return non-nil if PREFIX is prefix of LIST. + +Alias: `-is-prefix-p'" + (declare (pure t) (side-effect-free t)) + (--each-while list (equal (car prefix) it) + (!cdr prefix)) + (not prefix)) + +(defun -is-suffix? (suffix list) + "Return non-nil if SUFFIX is suffix of LIST. + +Alias: `-is-suffix-p'" + (declare (pure t) (side-effect-free t)) + (-is-prefix? (reverse suffix) (reverse list))) + +(defun -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'" + (declare (pure t) (side-effect-free t)) + (let (done) + (while (and (not done) list) + (setq done (-is-prefix? infix list)) + (!cdr list)) + done)) + +(defalias '-is-prefix-p '-is-prefix?) +(defalias '-is-suffix-p '-is-suffix?) +(defalias '-is-infix-p '-is-infix?) + +(defun -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 (copy-sequence list) comparator)) + +(defmacro --sort (form list) + "Anaphoric form of `-sort'." + (declare (debug (form form))) + `(-sort (lambda (it other) ,form) ,list)) + +(defun -list (&rest args) + "Return a list with ARGS. + +If first item of ARGS is already a list, simply return ARGS. If +not, return a list with ARGS as elements." + (declare (pure t) (side-effect-free t)) + (let ((arg (car args))) + (if (listp arg) arg args))) + +(defun -repeat (n x) + "Return a list with X repeated N times. +Return nil if N is less than 1." + (declare (pure t) (side-effect-free t)) + (let (ret) + (--dotimes n (!cons x ret)) + ret)) + +(defun -sum (list) + "Return the sum of LIST." + (declare (pure t) (side-effect-free t)) + (apply '+ list)) + +(defun -running-sum (list) + "Return a list with running sums of items in LIST. + +LIST must be non-empty." + (declare (pure t) (side-effect-free t)) + (unless (consp list) + (error "LIST must be non-empty")) + (-reductions '+ list)) + +(defun -product (list) + "Return the product of LIST." + (declare (pure t) (side-effect-free t)) + (apply '* list)) + +(defun -running-product (list) + "Return a list with running products of items in LIST. + +LIST must be non-empty." + (declare (pure t) (side-effect-free t)) + (unless (consp list) + (error "LIST must be non-empty")) + (-reductions '* list)) + +(defun -max (list) + "Return the largest value from LIST of numbers or markers." + (declare (pure t) (side-effect-free t)) + (apply 'max list)) + +(defun -min (list) + "Return the smallest value from LIST of numbers or markers." + (declare (pure t) (side-effect-free t)) + (apply 'min list)) + +(defun -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' which can transform the values before +comparing them." + (--reduce (if (funcall comparator it acc) it acc) list)) + +(defun -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' which can transform the values before +comparing them." + (--reduce (if (funcall comparator it acc) acc it) list)) + +(defmacro --max-by (form list) + "Anaphoric version of `-max-by'. + +The items for the comparator form are exposed as \"it\" and \"other\"." + (declare (debug (form form))) + `(-max-by (lambda (it other) ,form) ,list)) + +(defmacro --min-by (form list) + "Anaphoric version of `-min-by'. + +The items for the comparator form are exposed as \"it\" and \"other\"." + (declare (debug (form form))) + `(-min-by (lambda (it other) ,form) ,list)) + +(defun -iterate (fun init n) + "Return a list of iterated applications of FUN to INIT. + +This means a list of form: + + (init (fun init) (fun (fun init)) ...) + +N is the length of the returned list." + (if (= n 0) nil + (let ((r (list init))) + (--dotimes (1- n) + (push (funcall fun (car r)) r)) + (nreverse r)))) + +(defun -fix (fn list) + "Compute the (least) fixpoint of FN with initial input LIST. + +FN is called at least once, results are compared with `equal'." + (let ((re (funcall fn list))) + (while (not (equal list re)) + (setq list re) + (setq re (funcall fn re))) + re)) + +(defmacro --fix (form list) + "Anaphoric form of `-fix'." + `(-fix (lambda (it) ,form) ,list)) + +(defun -unfold (fun seed) + "Build a list from SEED using FUN. + +This is \"dual\" operation to `-reduce-r': while -reduce-r +consumes a list to produce a single value, `-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." + (let ((last (funcall fun seed)) r) + (while last + (push (car last) r) + (setq last (funcall fun (cdr last)))) + (nreverse r))) + +(defmacro --unfold (form seed) + "Anaphoric version of `-unfold'." + (declare (debug (form form))) + `(-unfold (lambda (it) ,form) ,seed)) + +(defun -cons-pair? (con) + "Return non-nil if CON is true cons pair. +That is (A . B) where B is not a list." + (declare (pure t) (side-effect-free t)) + (and (listp con) + (not (listp (cdr con))))) + +(defun -cons-to-list (con) + "Convert a cons pair to a list with `car' and `cdr' of the pair respectively." + (declare (pure t) (side-effect-free t)) + (list (car con) (cdr con))) + +(defun -value-to-list (val) + "Convert a value to a list. + +If the value is a cons pair, make a list with two elements, `car' +and `cdr' of the pair respectively. + +If the value is anything else, wrap it in a list." + (declare (pure t) (side-effect-free t)) + (cond + ((-cons-pair? val) (-cons-to-list val)) + (t (list val)))) + +(defun -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'. + +This is the same as calling `-tree-reduce-from' after `-tree-map' +but is twice as fast as it only traverse the structure once." + (cond + ((not tree) nil) + ((-cons-pair? tree) (funcall fn tree)) + ((listp tree) + (-reduce-r-from folder init-value (mapcar (lambda (x) (-tree-mapreduce-from fn folder init-value x)) tree))) + (t (funcall fn tree)))) + +(defmacro --tree-mapreduce-from (form folder init-value tree) + "Anaphoric form of `-tree-mapreduce-from'." + (declare (debug (form form form form))) + `(-tree-mapreduce-from (lambda (it) ,form) (lambda (it acc) ,folder) ,init-value ,tree)) + +(defun -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'. + +This is the same as calling `-tree-reduce' after `-tree-map' +but is twice as fast as it only traverse the structure once." + (cond + ((not tree) nil) + ((-cons-pair? tree) (funcall fn tree)) + ((listp tree) + (-reduce-r folder (mapcar (lambda (x) (-tree-mapreduce fn folder x)) tree))) + (t (funcall fn tree)))) + +(defmacro --tree-mapreduce (form folder tree) + "Anaphoric form of `-tree-mapreduce'." + (declare (debug (form form form))) + `(-tree-mapreduce (lambda (it) ,form) (lambda (it acc) ,folder) ,tree)) + +(defun -tree-map (fn tree) + "Apply FN to each element of TREE while preserving the tree structure." + (cond + ((not tree) nil) + ((-cons-pair? tree) (funcall fn tree)) + ((listp tree) + (mapcar (lambda (x) (-tree-map fn x)) tree)) + (t (funcall fn tree)))) + +(defmacro --tree-map (form tree) + "Anaphoric form of `-tree-map'." + (declare (debug (form form))) + `(-tree-map (lambda (it) ,form) ,tree)) + +(defun -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." + (cond + ((not tree) nil) + ((-cons-pair? tree) tree) + ((listp tree) + (-reduce-r-from fn init-value (mapcar (lambda (x) (-tree-reduce-from fn init-value x)) tree))) + (t tree))) + +(defmacro --tree-reduce-from (form init-value tree) + "Anaphoric form of `-tree-reduce-from'." + (declare (debug (form form form))) + `(-tree-reduce-from (lambda (it acc) ,form) ,init-value ,tree)) + +(defun -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' for how exactly are lists of zero or one element handled." + (cond + ((not tree) nil) + ((-cons-pair? tree) tree) + ((listp tree) + (-reduce-r fn (mapcar (lambda (x) (-tree-reduce fn x)) tree))) + (t tree))) + +(defmacro --tree-reduce (form tree) + "Anaphoric form of `-tree-reduce'." + (declare (debug (form form))) + `(-tree-reduce (lambda (it acc) ,form) ,tree)) + +(defun -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." + (if (funcall pred tree) + (funcall fun tree) + (if (and (listp tree) + (not (-cons-pair? tree))) + (-map (lambda (x) (-tree-map-nodes pred fun x)) tree) + tree))) + +(defmacro --tree-map-nodes (pred form tree) + "Anaphoric form of `-tree-map-nodes'." + `(-tree-map-nodes (lambda (it) ,pred) (lambda (it) ,form) ,tree)) + +(defun -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." + (cons tree + (when (funcall branch tree) + (-mapcat (lambda (x) (-tree-seq branch children x)) + (funcall children tree))))) + +(defmacro --tree-seq (branch children tree) + "Anaphoric form of `-tree-seq'." + `(-tree-seq (lambda (it) ,branch) (lambda (it) ,children) ,tree)) + +(defun -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." + (declare (pure t) (side-effect-free t)) + (-tree-map 'identity list)) + +(defun dash-enable-font-lock () + "Add syntax highlighting to dash functions, macros and magic values." + (eval-after-load 'lisp-mode + '(progn + (let ((new-keywords '( + "!cons" + "!cdr" + "-each" + "--each" + "-each-indexed" + "--each-indexed" + "-each-while" + "--each-while" + "-doto" + "-dotimes" + "--dotimes" + "-map" + "--map" + "-reduce-from" + "--reduce-from" + "-reduce" + "--reduce" + "-reduce-r-from" + "--reduce-r-from" + "-reduce-r" + "--reduce-r" + "-reductions-from" + "-reductions-r-from" + "-reductions" + "-reductions-r" + "-filter" + "--filter" + "-select" + "--select" + "-remove" + "--remove" + "-reject" + "--reject" + "-remove-first" + "--remove-first" + "-reject-first" + "--reject-first" + "-remove-last" + "--remove-last" + "-reject-last" + "--reject-last" + "-remove-item" + "-non-nil" + "-keep" + "--keep" + "-map-indexed" + "--map-indexed" + "-splice" + "--splice" + "-splice-list" + "--splice-list" + "-map-when" + "--map-when" + "-replace-where" + "--replace-where" + "-map-first" + "--map-first" + "-map-last" + "--map-last" + "-replace" + "-replace-first" + "-replace-last" + "-flatten" + "-flatten-n" + "-concat" + "-mapcat" + "--mapcat" + "-copy" + "-cons*" + "-snoc" + "-first" + "--first" + "-find" + "--find" + "-some" + "--some" + "-any" + "--any" + "-last" + "--last" + "-first-item" + "-second-item" + "-third-item" + "-fourth-item" + "-fifth-item" + "-last-item" + "-butlast" + "-count" + "--count" + "-any?" + "--any?" + "-some?" + "--some?" + "-any-p" + "--any-p" + "-some-p" + "--some-p" + "-some->" + "-some->>" + "-some-->" + "-all?" + "-all-p" + "--all?" + "--all-p" + "-every?" + "--every?" + "-all-p" + "--all-p" + "-every-p" + "--every-p" + "-none?" + "--none?" + "-none-p" + "--none-p" + "-only-some?" + "--only-some?" + "-only-some-p" + "--only-some-p" + "-slice" + "-take" + "-drop" + "-drop-last" + "-take-last" + "-take-while" + "--take-while" + "-drop-while" + "--drop-while" + "-split-at" + "-rotate" + "-insert-at" + "-replace-at" + "-update-at" + "--update-at" + "-remove-at" + "-remove-at-indices" + "-split-with" + "--split-with" + "-split-on" + "-split-when" + "--split-when" + "-separate" + "--separate" + "-partition-all-in-steps" + "-partition-in-steps" + "-partition-all" + "-partition" + "-partition-after-item" + "-partition-after-pred" + "-partition-before-item" + "-partition-before-pred" + "-partition-by" + "--partition-by" + "-partition-by-header" + "--partition-by-header" + "-group-by" + "--group-by" + "-interpose" + "-interleave" + "-unzip" + "-zip-with" + "--zip-with" + "-zip" + "-zip-fill" + "-zip-pair" + "-cycle" + "-pad" + "-annotate" + "--annotate" + "-table" + "-table-flat" + "-partial" + "-elem-index" + "-elem-indices" + "-find-indices" + "--find-indices" + "-find-index" + "--find-index" + "-find-last-index" + "--find-last-index" + "-select-by-indices" + "-select-columns" + "-select-column" + "-grade-up" + "-grade-down" + "->" + "->>" + "-->" + "-as->" + "-when-let" + "-when-let*" + "--when-let" + "-if-let" + "-if-let*" + "--if-let" + "-let*" + "-let" + "-lambda" + "-distinct" + "-uniq" + "-union" + "-intersection" + "-difference" + "-powerset" + "-permutations" + "-inits" + "-tails" + "-common-prefix" + "-contains?" + "-contains-p" + "-same-items?" + "-same-items-p" + "-is-prefix-p" + "-is-prefix?" + "-is-suffix-p" + "-is-suffix?" + "-is-infix-p" + "-is-infix?" + "-sort" + "--sort" + "-list" + "-repeat" + "-sum" + "-running-sum" + "-product" + "-running-product" + "-max" + "-min" + "-max-by" + "--max-by" + "-min-by" + "--min-by" + "-iterate" + "--iterate" + "-fix" + "--fix" + "-unfold" + "--unfold" + "-cons-pair?" + "-cons-to-list" + "-value-to-list" + "-tree-mapreduce-from" + "--tree-mapreduce-from" + "-tree-mapreduce" + "--tree-mapreduce" + "-tree-map" + "--tree-map" + "-tree-reduce-from" + "--tree-reduce-from" + "-tree-reduce" + "--tree-reduce" + "-tree-seq" + "--tree-seq" + "-tree-map-nodes" + "--tree-map-nodes" + "-clone" + "-rpartial" + "-juxt" + "-applify" + "-on" + "-flip" + "-const" + "-cut" + "-orfn" + "-andfn" + "-iteratefn" + "-fixfn" + "-prodfn" + )) + (special-variables '( + "it" + "it-index" + "acc" + "other" + ))) + (font-lock-add-keywords 'emacs-lisp-mode `((,(concat "\\_<" (regexp-opt special-variables 'paren) "\\_>") + 1 font-lock-variable-name-face)) 'append) + (font-lock-add-keywords 'emacs-lisp-mode `((,(concat "(\\s-*" (regexp-opt new-keywords 'paren) "\\_>") + 1 font-lock-keyword-face)) 'append)) + (--each (buffer-list) + (with-current-buffer it + (when (and (eq major-mode 'emacs-lisp-mode) + (boundp 'font-lock-mode) + font-lock-mode) + (font-lock-refresh-defaults))))))) + +(provide 'dash) +;;; dash.el ends here |