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authormattkae <mattkae@protonmail.com>2022-05-11 09:23:58 -0400
committermattkae <mattkae@protonmail.com>2022-05-11 09:23:58 -0400
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+;;; dash.el --- A modern list library for Emacs -*- lexical-binding: t -*-
+
+;; Copyright (C) 2012-2021 Free Software Foundation, Inc.
+
+;; Author: Magnar Sveen <magnars@gmail.com>
+;; Version: 2.19.1
+;; Package-Requires: ((emacs "24"))
+;; Keywords: extensions, lisp
+;; Homepage: https://github.com/magnars/dash.el
+
+;; 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/>.
+
+;;; Commentary:
+
+;; A modern list API for Emacs.
+;;
+;; See its overview at https://github.com/magnars/dash.el#functions.
+
+;;; Code:
+
+;; TODO: `gv' was introduced in Emacs 24.3, so remove this and all
+;; calls to `defsetf' when support for earlier versions is dropped.
+(eval-when-compile
+ (unless (fboundp 'gv-define-setter)
+ (require 'cl)))
+
+(defgroup dash ()
+ "Customize group for Dash, a modern list library."
+ :group 'extensions
+ :group 'lisp
+ :prefix "dash-")
+
+(defmacro !cons (car cdr)
+ "Destructive: Set CDR to the cons of CAR and CDR."
+ (declare (debug (form symbolp)))
+ `(setq ,cdr (cons ,car ,cdr)))
+
+(defmacro !cdr (list)
+ "Destructive: Set LIST to the cdr of LIST."
+ (declare (debug (symbolp)))
+ `(setq ,list (cdr ,list)))
+
+(defmacro --each (list &rest body)
+ "Evaluate BODY for each element of LIST and return nil.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating BODY.
+This is the anaphoric counterpart to `-each'."
+ (declare (debug (form body)) (indent 1))
+ (let ((l (make-symbol "list"))
+ (i (make-symbol "i")))
+ `(let ((,l ,list)
+ (,i 0)
+ it it-index)
+ (ignore it it-index)
+ (while ,l
+ (setq it (pop ,l) it-index ,i ,i (1+ ,i))
+ ,@body))))
+
+(defun -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'."
+ (declare (indent 1))
+ (ignore (mapc fn list)))
+
+(defalias '--each-indexed '--each)
+
+(defun -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'."
+ (declare (indent 1))
+ (--each list (funcall fn it-index it)))
+
+(defmacro --each-while (list pred &rest body)
+ "Evaluate BODY for each item in LIST, while PRED evaluates to non-nil.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating PRED or BODY. Once
+an element is reached for which PRED evaluates to nil, no further
+BODY is evaluated. The return value is always nil.
+This is the anaphoric counterpart to `-each-while'."
+ (declare (debug (form form body)) (indent 2))
+ (let ((l (make-symbol "list"))
+ (i (make-symbol "i"))
+ (elt (make-symbol "elt")))
+ `(let ((,l ,list)
+ (,i 0)
+ ,elt it it-index)
+ (ignore it it-index)
+ (while (and ,l (setq ,elt (pop ,l) it ,elt it-index ,i) ,pred)
+ (setq it ,elt it-index ,i ,i (1+ ,i))
+ ,@body))))
+
+(defun -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'."
+ (declare (indent 2))
+ (--each-while list (funcall pred it) (funcall fn it)))
+
+(defmacro --each-r (list &rest body)
+ "Evaluate BODY for each element of LIST in reversed order.
+Each element of LIST in turn, starting at its end, is bound to
+`it' and its index within LIST to `it-index' before evaluating
+BODY. The return value is always nil.
+This is the anaphoric counterpart to `-each-r'."
+ (declare (debug (form body)) (indent 1))
+ (let ((v (make-symbol "vector"))
+ (i (make-symbol "i")))
+ ;; Implementation note: building a vector is considerably faster
+ ;; than building a reversed list (vector takes less memory, so
+ ;; there is less GC), plus `length' comes naturally. In-place
+ ;; `nreverse' would be faster still, but BODY would be able to see
+ ;; that, even if the modification was undone before we return.
+ `(let* ((,v (vconcat ,list))
+ (,i (length ,v))
+ it it-index)
+ (ignore it it-index)
+ (while (> ,i 0)
+ (setq ,i (1- ,i) it-index ,i it (aref ,v ,i))
+ ,@body))))
+
+(defun -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'."
+ (--each-r list (funcall fn it)))
+
+(defmacro --each-r-while (list pred &rest body)
+ "Eval BODY for each item in reversed LIST, while PRED evals to non-nil.
+Each element of LIST in turn, starting at its end, is bound to
+`it' and its index within LIST to `it-index' before evaluating
+PRED or BODY. Once an element is reached for which PRED
+evaluates to nil, no further BODY is evaluated. The return value
+is always nil.
+This is the anaphoric counterpart to `-each-r-while'."
+ (declare (debug (form form body)) (indent 2))
+ (let ((v (make-symbol "vector"))
+ (i (make-symbol "i"))
+ (elt (make-symbol "elt")))
+ `(let* ((,v (vconcat ,list))
+ (,i (length ,v))
+ ,elt it it-index)
+ (ignore it it-index)
+ (while (when (> ,i 0)
+ (setq ,i (1- ,i) it-index ,i)
+ (setq ,elt (aref ,v ,i) it ,elt)
+ ,pred)
+ (setq it-index ,i it ,elt)
+ ,@body))))
+
+(defun -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'."
+ (--each-r-while list (funcall pred it) (funcall fn it)))
+
+(defmacro --dotimes (num &rest body)
+ "Evaluate BODY NUM times, presumably for side effects.
+BODY is evaluated with the local variable `it' temporarily bound
+to successive integers running from 0, inclusive, to NUM,
+exclusive. BODY is not evaluated if NUM is less than 1.
+This is the anaphoric counterpart to `-dotimes'."
+ (declare (debug (form body)) (indent 1))
+ (let ((n (make-symbol "num"))
+ (i (make-symbol "i")))
+ `(let ((,n ,num)
+ (,i 0)
+ it)
+ (ignore it)
+ (while (< ,i ,n)
+ (setq it ,i ,i (1+ ,i))
+ ,@body))))
+
+(defun -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'."
+ (declare (indent 1))
+ (--dotimes num (funcall fn it)))
+
+(defun -map (fn list)
+ "Apply FN to each item in LIST and return the list of results.
+
+This function's anaphoric counterpart is `--map'."
+ (mapcar fn list))
+
+(defmacro --map (form list)
+ "Eval FORM for each item in LIST and return the list of results.
+Each element of LIST in turn is bound to `it' before evaluating
+FORM.
+This is the anaphoric counterpart to `-map'."
+ (declare (debug (def-form form)))
+ `(mapcar (lambda (it) (ignore it) ,form) ,list))
+
+(defmacro --reduce-from (form init list)
+ "Accumulate a value by evaluating FORM across LIST.
+This macro is like `--each' (which see), but it additionally
+provides an accumulator variable `acc' which it successively
+binds to the result of evaluating FORM for the current LIST
+element before processing the next element. For the first
+element, `acc' is initialized with the result of evaluating INIT.
+The return value is the resulting value of `acc'. If LIST is
+empty, FORM is not evaluated, and the return value is the result
+of INIT.
+This is the anaphoric counterpart to `-reduce-from'."
+ (declare (debug (form form form)))
+ `(let ((acc ,init))
+ (--each ,list (setq acc ,form))
+ acc))
+
+(defun -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' and `-reduce-r'."
+ (--reduce-from (funcall fn acc it) init list))
+
+(defmacro --reduce (form list)
+ "Accumulate a value by evaluating FORM across LIST.
+This macro is like `--reduce-from' (which see), except the first
+element of LIST is taken as INIT. Thus if LIST contains a single
+item, it is returned without evaluating FORM. If LIST is empty,
+FORM is evaluated with `it' and `acc' bound to nil.
+This is the anaphoric counterpart to `-reduce'."
+ (declare (debug (form form)))
+ (let ((lv (make-symbol "list-value")))
+ `(let ((,lv ,list))
+ (if ,lv
+ (--reduce-from ,form (car ,lv) (cdr ,lv))
+ ;; Explicit nil binding pacifies lexical "variable left uninitialized"
+ ;; warning. See issue #377 and upstream https://bugs.gnu.org/47080.
+ (let ((acc nil) (it nil))
+ (ignore acc it)
+ ,form)))))
+
+(defun -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' and `-reduce-r'."
+ (if list
+ (-reduce-from fn (car list) (cdr list))
+ (funcall fn)))
+
+(defmacro --reduce-r-from (form init list)
+ "Accumulate a value by evaluating FORM across LIST in reverse.
+This macro is like `--reduce-from', except it starts from the end
+of LIST.
+This is the anaphoric counterpart to `-reduce-r-from'."
+ (declare (debug (form form form)))
+ `(let ((acc ,init))
+ (--each-r ,list (setq acc ,form))
+ acc))
+
+(defun -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' 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' and `-reduce'."
+ (--reduce-r-from (funcall fn it acc) init list))
+
+(defmacro --reduce-r (form list)
+ "Accumulate a value by evaluating FORM across LIST in reverse order.
+This macro is like `--reduce', except it starts from the end of
+LIST.
+This is the anaphoric counterpart to `-reduce-r'."
+ (declare (debug (form form)))
+ `(--reduce ,form (reverse ,list)))
+
+(defun -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' 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' and `-reduce'."
+ (if list
+ (--reduce-r (funcall fn it acc) list)
+ (funcall fn)))
+
+(defmacro --reductions-from (form init list)
+ "Return a list of FORM's intermediate reductions across LIST.
+That is, a list of the intermediate values of the accumulator
+when `--reduce-from' (which see) is called with the same
+arguments.
+This is the anaphoric counterpart to `-reductions-from'."
+ (declare (debug (form form form)))
+ `(nreverse
+ (--reduce-from (cons (let ((acc (car acc))) (ignore acc) ,form) acc)
+ (list ,init)
+ ,list)))
+
+(defun -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' (which see) is called with the same
+arguments.
+
+This function's anaphoric counterpart is `--reductions-from'.
+
+For other folds, see also `-reductions' and `-reductions-r'."
+ (--reductions-from (funcall fn acc it) init list))
+
+(defmacro --reductions (form list)
+ "Return a list of FORM's intermediate reductions across LIST.
+That is, a list of the intermediate values of the accumulator
+when `--reduce' (which see) is called with the same arguments.
+This is the anaphoric counterpart to `-reductions'."
+ (declare (debug (form form)))
+ (let ((lv (make-symbol "list-value")))
+ `(let ((,lv ,list))
+ (if ,lv
+ (--reductions-from ,form (car ,lv) (cdr ,lv))
+ (let (acc it)
+ (ignore acc it)
+ (list ,form))))))
+
+(defun -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' (which see) is called with the same arguments.
+
+This function's anaphoric counterpart is `--reductions'.
+
+For other folds, see also `-reductions' and `-reductions-r'."
+ (if list
+ (--reductions-from (funcall fn acc it) (car list) (cdr list))
+ (list (funcall fn))))
+
+(defmacro --reductions-r-from (form init list)
+ "Return a list of FORM's intermediate reductions across reversed LIST.
+That is, a list of the intermediate values of the accumulator
+when `--reduce-r-from' (which see) is called with the same
+arguments.
+This is the anaphoric counterpart to `-reductions-r-from'."
+ (declare (debug (form form form)))
+ `(--reduce-r-from (cons (let ((acc (car acc))) (ignore acc) ,form) acc)
+ (list ,init)
+ ,list))
+
+(defun -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' (which see) is called with the same
+arguments.
+
+This function's anaphoric counterpart is `--reductions-r-from'.
+
+For other folds, see also `-reductions' and `-reductions-r'."
+ (--reductions-r-from (funcall fn it acc) init list))
+
+(defmacro --reductions-r (form list)
+ "Return a list of FORM's intermediate reductions across reversed LIST.
+That is, a list of the intermediate values of the accumulator
+when `--reduce-re' (which see) is called with the same arguments.
+This is the anaphoric counterpart to `-reductions-r'."
+ (declare (debug (form list)))
+ (let ((lv (make-symbol "list-value")))
+ `(let ((,lv (reverse ,list)))
+ (if ,lv
+ (--reduce-from (cons (let ((acc (car acc))) (ignore acc) ,form) acc)
+ (list (car ,lv))
+ (cdr ,lv))
+ ;; Explicit nil binding pacifies lexical "variable left uninitialized"
+ ;; warning. See issue #377 and upstream https://bugs.gnu.org/47080.
+ (let ((acc nil) (it nil))
+ (ignore acc it)
+ (list ,form))))))
+
+(defun -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' (which see) is called with the same arguments.
+
+This function's anaphoric counterpart is `--reductions-r'.
+
+For other folds, see also `-reductions-r-from' and
+`-reductions'."
+ (if list
+ (--reductions-r (funcall fn it acc) list)
+ (list (funcall fn))))
+
+(defmacro --filter (form list)
+ "Return a new list of the items in LIST for which FORM evals to non-nil.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating FORM.
+This is the anaphoric counterpart to `-filter'.
+For the opposite operation, see also `--remove'."
+ (declare (debug (form form)))
+ (let ((r (make-symbol "result")))
+ `(let (,r)
+ (--each ,list (when ,form (push it ,r)))
+ (nreverse ,r))))
+
+(defun -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' and `-remove'."
+ (--filter (funcall pred it) list))
+
+(defalias '-select '-filter)
+(defalias '--select '--filter)
+
+(defmacro --remove (form list)
+ "Return a new list of the items in LIST for which FORM evals to nil.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating FORM.
+This is the anaphoric counterpart to `-remove'.
+For the opposite operation, 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'.
+
+This function's anaphoric counterpart is `--remove'.
+
+For similar operations, see also `-keep' and `-filter'."
+ (--remove (funcall pred it) list))
+
+(defalias '-reject '-remove)
+(defalias '--reject '--remove)
+
+(defmacro --remove-first (form list)
+ "Remove the first item from LIST for which FORM evals to non-nil.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating FORM. 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.
+This is the anaphoric counterpart to `-remove-first'."
+ (declare (debug (form form)))
+ (let ((front (make-symbol "front"))
+ (tail (make-symbol "tail")))
+ `(let ((,tail ,list) ,front)
+ (--each-while ,tail (not ,form)
+ (push (pop ,tail) ,front))
+ (if ,tail
+ (nconc (nreverse ,front) (cdr ,tail))
+ (nreverse ,front)))))
+
+(defun -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', `-remove-item', and `-remove-last'."
+ (--remove-first (funcall pred it) list))
+
+(defalias '-reject-first '-remove-first)
+(defalias '--reject-first '--remove-first)
+
+(defmacro --remove-last (form list)
+ "Remove the last item from LIST for which FORM evals to non-nil.
+Each element of LIST in turn is bound to `it' before evaluating
+FORM. The result is a copy of LIST regardless of whether an
+element is removed.
+This is the anaphoric counterpart to `-remove-last'."
+ (declare (debug (form form)))
+ `(nreverse (--remove-first ,form (reverse ,list))))
+
+(defun -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', `-remove-item', and `-remove-first'."
+ (--remove-last (funcall pred it) list))
+
+(defalias '-reject-last '-remove-last)
+(defalias '--reject-last '--remove-last)
+
+(defalias '-remove-item #'remove
+ "Return a copy of LIST with all occurrences of ITEM removed.
+The comparison is done with `equal'.
+\n(fn ITEM LIST)")
+
+(defmacro --keep (form list)
+ "Eval FORM for each item in LIST and return the non-nil results.
+Like `--filter', but returns the non-nil results of FORM instead
+of the corresponding elements of LIST. Each element of LIST in
+turn is bound to `it' and its index within LIST to `it-index'
+before evaluating FORM.
+This is the anaphoric counterpart to `-keep'."
+ (declare (debug (form form)))
+ (let ((r (make-symbol "result"))
+ (m (make-symbol "mapped")))
+ `(let (,r)
+ (--each ,list (let ((,m ,form)) (when ,m (push ,m ,r))))
+ (nreverse ,r))))
+
+(defun -keep (fn list)
+ "Return a new list of the non-nil results of applying FN to each item in LIST.
+Like `-filter', but returns the non-nil results of FN instead of
+the corresponding elements of LIST.
+
+Its anaphoric counterpart is `--keep'."
+ (--keep (funcall fn it) list))
+
+(defun -non-nil (list)
+ "Return a copy of LIST with all nil items removed."
+ (declare (pure t) (side-effect-free t))
+ (--filter it list))
+
+(defmacro --map-indexed (form list)
+ "Eval FORM for each item in LIST and return the list of results.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating FORM. This is like
+`--map', but additionally makes `it-index' available to FORM.
+
+This is the anaphoric counterpart to `-map-indexed'."
+ (declare (debug (form form)))
+ (let ((r (make-symbol "result")))
+ `(let (,r)
+ (--each ,list
+ (push ,form ,r))
+ (nreverse ,r))))
+
+(defun -map-indexed (fn list)
+ "Apply FN to each index and item in LIST and return the list of results.
+This is like `-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'."
+ (--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'."
+ (declare (debug (def-form def-form form)))
+ `(-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'."
+ (declare (debug (def-form def-form form)))
+ `(-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 occurrence 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 occurrence 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))
+
+(defmacro --iterate (form init n)
+ "Anaphoric version of `-iterate'."
+ (declare (debug (form form form)))
+ (let ((res (make-symbol "result"))
+ (len (make-symbol "n")))
+ `(let ((,len ,n))
+ (when (> ,len 0)
+ (let* ((it ,init)
+ (,res (list it)))
+ (dotimes (_ (1- ,len))
+ (push (setq it ,form) ,res))
+ (nreverse ,res))))))
+
+(defun -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 (funcall fun it) init n))
+
+(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)))
+
+(defun -flatten-n (num list)
+ "Flatten NUM levels of a nested LIST.
+
+See also: `-flatten'"
+ (declare (pure t) (side-effect-free t))
+ (dotimes (_ num)
+ (setq list (apply #'append (mapcar #'-list list))))
+ list)
+
+(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'."
+ (declare (debug (def-form def-form form)))
+ `(-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'."
+ (declare (debug (def-form form form)))
+ `(-splice-list (lambda (it) ,pred) ,new-list ,list))
+
+(defun -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."
+ (declare (pure t) (side-effect-free t))
+ (let* ((len (length args))
+ (tail (nthcdr (- len 2) args))
+ (last (cdr tail)))
+ (if (null last)
+ (car args)
+ (setcdr tail (car last))
+ 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)
+ "Return the first item in LIST for which FORM evals to non-nil.
+Return nil if no such element is found.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating FORM.
+This is the anaphoric counterpart to `-first'."
+ (declare (debug (form form)))
+ (let ((n (make-symbol "needle")))
+ `(let (,n)
+ (--each-while ,list (or (not ,form)
+ (ignore (setq ,n it))))
+ ,n)))
+
+(defun -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 (funcall pred it) list))
+
+(defalias '-find '-first)
+(defalias '--find '--first)
+
+(defmacro --some (form list)
+ "Return non-nil if FORM evals to non-nil for at least one item in LIST.
+If so, return the first such result of FORM.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating FORM.
+This is the anaphoric counterpart to `-some'."
+ (declare (debug (form form)))
+ (let ((n (make-symbol "needle")))
+ `(let (,n)
+ (--each-while ,list (not (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'.
+
+This function's anaphoric counterpart is `--some'."
+ (--some (funcall pred it) list))
+
+(defalias '-any '-some)
+(defalias '--any '--some)
+
+(defmacro --every (form list)
+ "Return non-nil if FORM evals to non-nil for all items in LIST.
+If so, return the last such result of FORM. Otherwise, once an
+item is reached for which FORM yields nil, return nil without
+evaluating FORM for any further LIST elements.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating FORM.
+
+This macro is like `--every-p', but on success returns the last
+non-nil result of FORM instead of just t.
+
+This is the anaphoric counterpart to `-every'."
+ (declare (debug (form form)))
+ (let ((a (make-symbol "all")))
+ `(let ((,a t))
+ (--each-while ,list (setq ,a ,form))
+ ,a)))
+
+(defun -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 (funcall pred it) list))
+
+(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
+ (if (fboundp 'caddr)
+ #'caddr
+ (lambda (list) (car (cddr list))))
+ "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))))))
+
+(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)))
+
+;; Use `with-no-warnings' to suppress unbound `-last-item' or
+;; undefined `gv--defsetter' warnings arising from both
+;; `gv-define-setter' and `defsetf' in certain Emacs versions.
+(with-no-warnings
+ (if (fboundp 'gv-define-setter)
+ (gv-define-setter -last-item (val x) `(setcar (last ,x) ,val))
+ (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? (obj)
+ "Return OBJ as a boolean value (t or nil)."
+ (declare (pure t) (side-effect-free t))
+ (and obj t))
+
+(defmacro --any? (form list)
+ "Anaphoric form of `-any?'."
+ (declare (debug (form form)))
+ `(and (--some ,form ,list) t))
+
+(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)
+ "Return t if FORM evals to non-nil for all items in LIST.
+Otherwise, once an item is reached for which FORM yields nil,
+return nil without evaluating FORM for any further LIST elements.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating FORM.
+
+The similar macro `--every' is more widely useful, since it
+returns the last non-nil result of FORM instead of just t on
+success.
+
+Alias: `--all-p', `--every-p', `--every?'.
+
+This is the anaphoric counterpart to `-all?'."
+ (declare (debug (form form)))
+ `(and (--every ,form ,list) t))
+
+(defun -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' 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? (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)))
+
+(defmacro --take-while (form list)
+ "Take successive items from LIST for which FORM evals to non-nil.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating FORM. Return a new
+list of the successive elements from the start of LIST for which
+FORM evaluates to non-nil.
+This is the anaphoric counterpart to `-take-while'."
+ (declare (debug (form form)))
+ (let ((r (make-symbol "result")))
+ `(let (,r)
+ (--each-while ,list ,form (push it ,r))
+ (nreverse ,r))))
+
+(defun -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'."
+ (--take-while (funcall pred it) list))
+
+(defmacro --drop-while (form list)
+ "Drop successive items from LIST for which FORM evals to non-nil.
+Each element of LIST in turn is bound to `it' and its index
+within LIST to `it-index' before evaluating FORM. Return the
+tail (not a copy) of LIST starting from its first element for
+which FORM evaluates to nil.
+This is the anaphoric counterpart to `-drop-while'."
+ (declare (debug (form form)))
+ (let ((l (make-symbol "list")))
+ `(let ((,l ,list))
+ (--each-while ,l ,form (pop ,l))
+ ,l)))
+
+(defun -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'."
+ (--drop-while (funcall pred it) list))
+
+(defun -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'."
+ (declare (pure t) (side-effect-free t))
+ (--take-while (< it-index n) list))
+
+(defun -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'."
+ (declare (pure t) (side-effect-free t))
+ (copy-sequence (last list n)))
+
+(defalias '-drop #'nthcdr
+ "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'.
+\n(fn N LIST)")
+
+(defun -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'."
+ (declare (pure t) (side-effect-free t))
+ (nbutlast (copy-sequence list) n))
+
+(defun -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' and `-drop', respectively, but the split
+is done in a single list traversal."
+ (declare (pure t) (side-effect-free t))
+ (let (result)
+ (--each-while list (< it-index n)
+ (push (pop list) result))
+ (list (nreverse result) list)))
+
+(defun -rotate (n list)
+ "Rotate LIST N places to the right (left if N is negative).
+The time complexity is O(n)."
+ (declare (pure t) (side-effect-free t))
+ (cond ((null list) ())
+ ((zerop n) (copy-sequence list))
+ ((let* ((len (length list))
+ (n-mod-len (mod n len))
+ (new-tail-len (- len n-mod-len)))
+ (append (nthcdr new-tail-len list) (-take new-tail-len 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 def-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 (def-form form)))
+ `(-split-when (lambda (it) (equal it ,item)) ,list))
+
+(defmacro --split-when (form list)
+ "Anaphoric version of `-split-when'."
+ (declare (debug (def-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 dash--partition-all-in-steps-reversed (n step list)
+ "Used by `-partition-all-in-steps' and `-partition-in-steps'."
+ (when (< step 1)
+ (signal 'wrong-type-argument
+ `("Step size < 1 results in juicy infinite loops" ,step)))
+ (let (result)
+ (while list
+ (push (-take n list) result)
+ (setq list (nthcdr 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 (dash--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 (dash--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))
+
+(defmacro --partition-after-pred (form list)
+ "Partition LIST after each element for which FORM evaluates to non-nil.
+Each element of LIST in turn is bound to `it' before evaluating
+FORM.
+
+This is the anaphoric counterpart to `-partition-after-pred'."
+ (let ((l (make-symbol "list"))
+ (r (make-symbol "result"))
+ (s (make-symbol "sublist")))
+ `(let ((,l ,list) ,r ,s)
+ (when ,l
+ (--each ,l
+ (push it ,s)
+ (when ,form
+ (push (nreverse ,s) ,r)
+ (setq ,s ())))
+ (when ,s
+ (push (nreverse ,s) ,r))
+ (nreverse ,r)))))
+
+(defun -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 (funcall pred it) list))
+
+(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-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'"
+ (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)))
+ (nreverse results))))
+
+(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.
+
+Use `-zip-lists' if you need the return value to always be a list
+of lists.
+
+Alias: `-zip-pair'
+
+See also: `-zip-lists'"
+ (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 compatibility, 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).
+
+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'"
+ (apply '-zip lists))
+
+(defun -cycle (list)
+ "Return an infinite circular copy of LIST.
+The returned list cycles through the elements of LIST and repeats
+from the beginning."
+ (declare (pure t) (side-effect-free t))
+ ;; Also works with sequences that aren't lists.
+ (let ((newlist (append 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 (def-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 -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 (def-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 (def-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'."
+ (declare (debug (def-form form)))
+ `(-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 ->)
+ (indent 1))
+ (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 ->)
+ (indent 1))
+ (if (null form) x
+ (let ((result (make-symbol "result")))
+ `(-some->> (-when-let (,result ,x)
+ (->> ,result ,form))
+ ,@more))))
+
+(defmacro -some--> (expr &rest forms)
+ "Thread EXPR through FORMS via `-->', 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."
+ (declare (debug (form &rest &or symbolp consp)) (indent 1))
+ (if (null forms) expr
+ (let ((result (make-symbol "result")))
+ `(-some--> (-when-let (,result ,expr)
+ (--> ,result ,(car forms)))
+ ,@(cdr forms)))))
+
+(defmacro -doto (init &rest forms)
+ "Evaluate INIT and pass it as argument to FORMS with `->'.
+The RESULT of evaluating INIT is threaded through each of FORMS
+individually using `->', which see. The return value is RESULT,
+which FORMS may have modified by side effect."
+ (declare (debug (form &rest &or symbolp consp)) (indent 1))
+ (let ((retval (make-symbol "result")))
+ `(let ((,retval ,init))
+ ,@(mapcar (lambda (form) `(-> ,retval ,form)) forms)
+ ,retval)))
+
+(defmacro --doto (init &rest forms)
+ "Anaphoric form of `-doto'.
+This just evaluates INIT, binds the result to `it', evaluates
+FORMS, and returns the final value of `it'.
+Note: `it' need not be used in each form."
+ (declare (debug (form body)) (indent 1))
+ `(let ((it ,init))
+ ,@forms
+ it))
+
+(defun -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."
+ (->> (--map-indexed (cons it it-index) list)
+ (-sort (lambda (it other) (funcall comparator (car it) (car other))))
+ (mapcar #'cdr)))
+
+(defun -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."
+ (->> (--map-indexed (cons it it-index) list)
+ (-sort (lambda (it other) (funcall comparator (car other) (car it))))
+ (mapcar #'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--get-expand-function (type)
+ "Get expand function name for TYPE."
+ (intern-soft (format "dash-expand:%s" type)))
+
+(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))
+ (functionp (dash--get-expand-function (car match-form))))
+ (dash--match-kv (dash--match-kv-normalize-match-form 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--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))
+ `(substring ,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-normalize-match-form (pattern)
+ "Normalize kv PATTERN.
+
+This method normalizes PATTERN to the format expected by
+`dash--match-kv'. See `-let' for the specification."
+ (let ((normalized (list (car pattern)))
+ (skip nil)
+ (fill-placeholder (make-symbol "--dash-fill-placeholder--")))
+ (-each (apply '-zip (-pad fill-placeholder (cdr pattern) (cddr pattern)))
+ (lambda (pair)
+ (let ((current (car pair))
+ (next (cdr pair)))
+ (if skip
+ (setq skip nil)
+ (if (or (eq fill-placeholder next)
+ (not (or (and (symbolp next)
+ (not (keywordp next))
+ (not (eq next t))
+ (not (eq next nil)))
+ (and (consp next)
+ (not (eq (car next) 'quote)))
+ (vectorp next))))
+ (progn
+ (cond
+ ((keywordp current)
+ (push current normalized)
+ (push (intern (substring (symbol-name current) 1)) normalized))
+ ((stringp current)
+ (push current normalized)
+ (push (intern current) normalized))
+ ((and (consp current)
+ (eq (car current) 'quote))
+ (push current normalized)
+ (push (cadr current) normalized))
+ (t (error "-let: found key `%s' in kv destructuring but its pattern `%s' is invalid and can not be derived from the key" current next)))
+ (setq skip nil))
+ (push current normalized)
+ (push next normalized)
+ (setq skip t))))))
+ (nreverse normalized)))
+
+(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-expand:&hash (key source)
+ "Generate extracting KEY from SOURCE for &hash destructuring."
+ `(gethash ,key ,source))
+
+(defun dash-expand:&plist (key source)
+ "Generate extracting KEY from SOURCE for &plist destructuring."
+ `(plist-get ,source ,key))
+
+(defun dash-expand:&alist (key source)
+ "Generate extracting KEY from SOURCE for &alist destructuring."
+ `(cdr (assoc ,key ,source)))
+
+(defun dash-expand:&hash? (key source)
+ "Generate extracting KEY from SOURCE for &hash? destructuring.
+Similar to &hash but check whether the map is not nil."
+ (let ((src (make-symbol "src")))
+ `(let ((,src ,source))
+ (when ,src (gethash ,key ,src)))))
+
+(defalias 'dash-expand:&keys 'dash-expand:&plist)
+
+(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
+ (funcall (dash--get-expand-function type) 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))))
+ ((functionp (dash--get-expand-function (car match-form)))
+ (dash--match-kv (dash--match-kv-normalize-match-form 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 (substring match-form 2) s))))
+ (t (dash--match-vector match-form source))))))
+
+(defun dash--normalize-let-varlist (varlist)
+ "Normalize VARLIST so that every binding is a list.
+
+`let' allows specifying a binding which is not a list but simply
+the place which is then automatically bound to nil, such that all
+three of the following are identical and evaluate to nil.
+
+ (let (a) a)
+ (let ((a)) a)
+ (let ((a nil)) a)
+
+This function normalizes all of these to the last form."
+ (--map (if (consp it) it (list it nil)) varlist))
+
+(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 [&or (sexp form) sexp]) body))
+ (indent 1))
+ (let* ((varlist (dash--normalize-let-varlist varlist))
+ (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.
+ 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."
+ (declare (debug ([&or (&rest [&or (sexp form) sexp])
+ (vector [&rest [sexp form]])]
+ body))
+ (indent 1))
+ (if (vectorp varlist)
+ `(let* ,(dash--match (aref varlist 0) (aref varlist 1))
+ ,@body)
+ (let* ((varlist (dash--normalize-let-varlist varlist))
+ (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 a description of the destructuring mechanism."
+ (declare (doc-string 2) (indent defun)
+ (debug (&define sexp
+ [&optional stringp]
+ [&optional ("interactive" interactive)]
+ def-body)))
+ (cond
+ ((nlistp match-form)
+ (signal 'wrong-type-argument (list #'listp match-form)))
+ ;; No destructuring, so just return regular `lambda' for speed.
+ ((-all? #'symbolp match-form)
+ `(lambda ,match-form ,@body))
+ ((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 create the extra bindings to ensure that.
+ ;; We should find a way to optimize that. Not critical however.
+ `(lambda ,(mapcar #'cadr inputs)
+ (-let* ,inputs ,@body))))))
+
+(defmacro -setq (&rest forms)
+ "Bind each MATCH-FORM to the value of its VAL.
+
+MATCH-FORM destructuring is done according to the rules of `-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.
+
+\(fn [MATCH-FORM VAL]...)"
+ (declare (debug (&rest sexp form))
+ (indent 1))
+ (when (= (mod (length forms) 2) 1)
+ (signal 'wrong-number-of-arguments (list '-setq (1+ (length forms)))))
+ (let* ((forms-and-sources
+ ;; First get all the necessary mappings with all the
+ ;; intermediate bindings.
+ (-map (lambda (x) (dash--match (car x) (cadr x)))
+ (-partition 2 forms)))
+ ;; To preserve the logic of dynamic scoping we must ensure
+ ;; that we `setq' the variables outside of the `let*' form
+ ;; which holds the destructured intermediate values. For
+ ;; this we generate for each variable a placeholder which is
+ ;; bound to (lexically) the result of the destructuring.
+ ;; Then outside of the helper `let*' form we bind all the
+ ;; original variables to their respective placeholders.
+ ;; TODO: There is a lot of room for possible optimization,
+ ;; for start playing with `special-variable-p' to eliminate
+ ;; unnecessary re-binding.
+ (variables-to-placeholders
+ (-mapcat
+ (lambda (bindings)
+ (-map
+ (lambda (binding)
+ (let ((var (car binding)))
+ (list var (make-symbol (concat "--dash-binding-" (symbol-name var) "--")))))
+ (--filter (not (string-prefix-p "--" (symbol-name (car it)))) bindings)))
+ forms-and-sources)))
+ `(let ,(-map 'cadr variables-to-placeholders)
+ (let* ,(-flatten-n 1 forms-and-sources)
+ (setq ,@(-flatten (-map 'reverse variables-to-placeholders))))
+ (setq ,@(-flatten variables-to-placeholders)))))
+
+(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'"
+ ;; Implementation note: The speedup gained from hash table lookup
+ ;; starts to outweigh its overhead for lists of length greater than
+ ;; 32. See discussion in PR #305.
+ (let* ((len (length list))
+ (lut (and (> len 32)
+ ;; Check that `-compare-fn' is a valid hash-table
+ ;; lookup function or `nil'.
+ (memq -compare-fn '(nil equal eq eql))
+ (make-hash-table :test (or -compare-fn #'equal)
+ :size len))))
+ (if lut
+ (--filter (unless (gethash it lut)
+ (puthash it t lut))
+ list)
+ (--each list (unless (-contains? lut it) (!cons it lut)))
+ (nreverse lut))))
+
+(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."
+ (let ((res (list list)))
+ (setq list (reverse list))
+ (while list
+ (push (reverse (!cdr list)) res))
+ res))
+
+(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 -common-suffix (&rest lists)
+ "Return the longest common suffix of LISTS."
+ (nreverse (apply #'-common-prefix (mapcar #'reverse 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 a prefix of LIST.
+
+Alias: `-is-prefix-p'."
+ (declare (pure t) (side-effect-free t))
+ (--each-while list (and (equal (car prefix) it)
+ (!cdr prefix)))
+ (null prefix))
+
+(defun -is-suffix? (suffix list)
+ "Return non-nil if SUFFIX is a suffix of LIST.
+
+Alias: `-is-suffix-p'."
+ (declare (pure t) (side-effect-free t))
+ (equal suffix (last list (length suffix))))
+
+(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 (def-form form)))
+ `(-sort (lambda (it other) ,form) ,list))
+
+(defun -list (&optional arg &rest args)
+ "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."
+ (declare (advertised-calling-convention (arg) "2.18.0")
+ (pure t) (side-effect-free t))
+ (if (listp arg) arg (cons arg args)))
+
+(defun -repeat (n x)
+ "Return a new list of length N with each element being X.
+Return nil if N is less than 1."
+ (declare (pure t) (side-effect-free t))
+ (and (natnump n) (make-list n x)))
+
+(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))
+ (or list (signal 'wrong-type-argument (list #'consp list)))
+ (-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))
+ (or list (signal 'wrong-type-argument (list #'consp list)))
+ (-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 (def-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 (def-form form)))
+ `(-min-by (lambda (it other) ,form) ,list))
+
+(defun -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."
+ (declare (pure t) (side-effect-free t))
+ (unless (natnump count)
+ (signal 'wrong-type-argument (list #'natnump count)))
+ (or start (setq start 0))
+ (or step (setq step 1))
+ (if (zerop step)
+ (make-list count start)
+ (--iterate (+ it step) start count)))
+
+(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'."
+ (declare (debug (def-form form)))
+ `(-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 (def-form form)))
+ `(-unfold (lambda (it) ,form) ,seed))
+
+(defun -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'."
+ (declare (pure t) (side-effect-free t))
+ (nlistp (cdr-safe obj)))
+
+(defalias '-cons-pair-p '-cons-pair?)
+
+(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 (def-form def-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 (def-form def-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 (def-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 (def-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 (def-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'."
+ (declare (debug (def-form def-form form)))
+ `(-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'."
+ (declare (debug (def-form def-form form)))
+ `(-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))
+
+;;; Combinators
+
+(defalias '-partial #'apply-partially)
+
+(defun -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', except the arguments are fixed
+starting from the right rather than the left."
+ (declare (pure t) (side-effect-free t))
+ (lambda (&rest args-before) (apply fn (append args-before args))))
+
+(defun -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."
+ (declare (pure t) (side-effect-free t))
+ (lambda (&rest args) (mapcar (lambda (x) (apply x args)) fns)))
+
+(defun -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."
+ (declare (pure t) (side-effect-free t))
+ (let* ((fns (nreverse fns))
+ (head (car fns))
+ (tail (cdr fns)))
+ (cond (tail
+ (lambda (&rest args)
+ (--reduce-from (funcall it acc) (apply head args) tail)))
+ (fns head)
+ ((lambda (&optional arg &rest _) arg)))))
+
+(defun -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."
+ (declare (pure t) (side-effect-free t))
+ (lambda (args) (apply fn args)))
+
+(defun -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+)) = (+)"
+ (declare (pure t) (side-effect-free t))
+ (lambda (&rest args)
+ ;; This unrolling seems to be a relatively cheap way to keep the
+ ;; overhead of `mapcar' + `apply' in check.
+ (cond ((cddr args)
+ (apply op (mapcar trans args)))
+ ((cdr args)
+ (funcall op (funcall trans (car args)) (funcall trans (cadr args))))
+ (args
+ (funcall op (funcall trans (car args))))
+ ((funcall op)))))
+
+(defun -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'."
+ (declare (pure t) (side-effect-free t))
+ (lambda (&rest args) ;; Open-code for speed.
+ (cond ((cddr args) (apply fn (nreverse args)))
+ ((cdr args) (funcall fn (cadr args) (car args)))
+ (args (funcall fn (car args)))
+ ((funcall fn)))))
+
+(defun -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', and applies FN to the result.
+
+See also: `-flip'."
+ (declare (pure t) (side-effect-free t))
+ (if (zerop n)
+ fn
+ (let ((even (= (% n 2) 0)))
+ (lambda (&rest args)
+ (cond ((cddr args) ;; Open-code for speed.
+ (apply fn (-rotate n args)))
+ ((cdr args)
+ (let ((fst (car args))
+ (snd (cadr args)))
+ (funcall fn (if even fst snd) (if even snd fst))))
+ (args
+ (funcall fn (car args)))
+ ((funcall fn)))))))
+
+(defun -const (c)
+ "Return a function that returns C ignoring any additional arguments.
+
+In types: a -> b -> a"
+ (declare (pure t) (side-effect-free t))
+ (lambda (&rest _) c))
+
+(defmacro -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."
+ (declare (debug (&optional sexp &rest &or "<>" form)))
+ (let* ((i 0)
+ (args (--keep (when (eq it '<>)
+ (setq i (1+ i))
+ (make-symbol (format "D%d" i)))
+ params)))
+ `(lambda ,args
+ ,(let ((body (--map (if (eq it '<>) (pop args) it) params)))
+ (if (eq (car params) '<>)
+ (cons #'funcall body)
+ body)))))
+
+(defun -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' and `-orfn'."
+ (declare (pure t) (side-effect-free t))
+ (lambda (&rest args) (not (apply pred args))))
+
+(defun -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' and `-not'."
+ (declare (pure t) (side-effect-free t))
+ ;; Open-code for speed.
+ (cond ((cdr preds) (lambda (&rest args) (--some (apply it args) preds)))
+ (preds (car preds))
+ (#'ignore)))
+
+(defun -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' and `-not'."
+ (declare (pure t) (side-effect-free t))
+ ;; Open-code for speed.
+ (cond ((cdr preds) (lambda (&rest args) (--every (apply it args) preds)))
+ (preds (car preds))
+ ;; As a `pure' function, this runtime check may generate
+ ;; backward-incompatible bytecode for `(-andfn)' at compile-time,
+ ;; but I doubt that's a problem in practice (famous last words).
+ ((fboundp 'always) #'always)
+ ((lambda (&rest _) t))))
+
+(defun -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' 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)))."
+ (lambda (x) (--dotimes n (setq x (funcall fn x))) x))
+
+(defun -counter (&optional beg end inc)
+ "Return a closure that counts from BEG to END, with increment INC.
+
+The closure will return the next value in the counting sequence
+each time it is called, and nil after END is reached. BEG
+defaults to 0, INC defaults to 1, and if END is nil, the counter
+will increment indefinitely.
+
+The closure accepts any number of arguments, which are discarded."
+ (let ((inc (or inc 1))
+ (n (or beg 0)))
+ (lambda (&rest _)
+ (when (or (not end) (< n end))
+ (prog1 n
+ (setq n (+ n inc)))))))
+
+(defvar -fixfn-max-iterations 1000
+ "The default maximum number of iterations performed by `-fixfn'
+ unless otherwise specified.")
+
+(defun -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."
+ (let ((eqfn (or equal-test 'equal))
+ (haltfn (or halt-test
+ (-not
+ (-counter 0 -fixfn-max-iterations)))))
+ (lambda (x)
+ (let ((re (funcall fn x))
+ (halt? (funcall haltfn x)))
+ (while (and (not halt?) (not (funcall eqfn x re)))
+ (setq x re
+ re (funcall fn re)
+ halt? (funcall haltfn re)))
+ (if halt? (cons 'halted halt?)
+ re)))))
+
+(defun -prodfn (&rest fns)
+ "Take a list of n functions and return a function that takes a
+list of length n, applying i-th function to i-th 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))"
+ (lambda (x) (-zip-with 'funcall fns x)))
+
+;;; Font lock
+
+(defvar dash--keywords
+ `(;; TODO: Do not fontify the following automatic variables
+ ;; globally; detect and limit to their local anaphoric scope.
+ (,(rx symbol-start (| "acc" "it" "it-index" "other") symbol-end)
+ 0 font-lock-variable-name-face)
+ ;; Macros in dev/examples.el. Based on `lisp-mode-symbol-regexp'.
+ (,(rx ?\( (group (| "defexamples" "def-example-group")) symbol-end
+ (+ (in "\t "))
+ (group (* (| (syntax word) (syntax symbol) (: ?\\ nonl)))))
+ (1 font-lock-keyword-face)
+ (2 font-lock-function-name-face))
+ ;; Symbols in dev/examples.el.
+ ,(rx symbol-start (| "=>" "~>" "!!>") symbol-end)
+ ;; Elisp macro fontification was static prior to Emacs 25.
+ ,@(when (< emacs-major-version 25)
+ (let ((macs '("!cdr"
+ "!cons"
+ "-->"
+ "--all?"
+ "--annotate"
+ "--any?"
+ "--count"
+ "--dotimes"
+ "--doto"
+ "--drop-while"
+ "--each"
+ "--each-r"
+ "--each-r-while"
+ "--each-while"
+ "--filter"
+ "--find-index"
+ "--find-indices"
+ "--find-last-index"
+ "--first"
+ "--fix"
+ "--group-by"
+ "--if-let"
+ "--iterate"
+ "--keep"
+ "--last"
+ "--map"
+ "--map-first"
+ "--map-indexed"
+ "--map-last"
+ "--map-when"
+ "--mapcat"
+ "--max-by"
+ "--min-by"
+ "--none?"
+ "--only-some?"
+ "--partition-by"
+ "--partition-by-header"
+ "--reduce"
+ "--reduce-from"
+ "--reduce-r"
+ "--reduce-r-from"
+ "--reductions"
+ "--reductions-from"
+ "--reductions-r"
+ "--reductions-r-from"
+ "--remove"
+ "--remove-first"
+ "--remove-last"
+ "--separate"
+ "--some"
+ "--sort"
+ "--splice"
+ "--splice-list"
+ "--split-when"
+ "--split-with"
+ "--take-while"
+ "--tree-map"
+ "--tree-map-nodes"
+ "--tree-mapreduce"
+ "--tree-mapreduce-from"
+ "--tree-reduce"
+ "--tree-reduce-from"
+ "--tree-seq"
+ "--unfold"
+ "--update-at"
+ "--when-let"
+ "--zip-with"
+ "->"
+ "->>"
+ "-as->"
+ "-doto"
+ "-if-let"
+ "-if-let*"
+ "-lambda"
+ "-let"
+ "-let*"
+ "-setq"
+ "-some-->"
+ "-some->"
+ "-some->>"
+ "-split-on"
+ "-when-let"
+ "-when-let*")))
+ `((,(concat "(" (regexp-opt macs 'symbols)) . 1)))))
+ "Font lock keywords for `dash-fontify-mode'.")
+
+(defcustom dash-fontify-mode-lighter nil
+ "Mode line lighter for `dash-fontify-mode'.
+Either a string to display in the mode line when
+`dash-fontify-mode' is on, or nil to display
+nothing (the default)."
+ :package-version '(dash . "2.18.0")
+ :group 'dash
+ :type '(choice (string :tag "Lighter" :value " Dash")
+ (const :tag "Nothing" nil)))
+
+;;;###autoload
+(define-minor-mode dash-fontify-mode
+ "Toggle fontification of Dash special variables.
+
+Dash-Fontify mode is a buffer-local minor mode intended for Emacs
+Lisp buffers. Enabling it causes the special variables bound in
+anaphoric Dash macros to be fontified. These anaphoras include
+`it', `it-index', `acc', and `other'. In older Emacs versions
+which do not dynamically detect macros, Dash-Fontify mode
+additionally fontifies Dash macro calls.
+
+See also `dash-fontify-mode-lighter' and
+`global-dash-fontify-mode'."
+ :group 'dash :lighter dash-fontify-mode-lighter
+ (if dash-fontify-mode
+ (font-lock-add-keywords nil dash--keywords t)
+ (font-lock-remove-keywords nil dash--keywords))
+ (cond ((fboundp 'font-lock-flush) ;; Added in Emacs 25.
+ (font-lock-flush))
+ ;; `font-lock-fontify-buffer' unconditionally enables
+ ;; `font-lock-mode' and is marked `interactive-only' in later
+ ;; Emacs versions which have `font-lock-flush', so we guard
+ ;; and pacify as needed, respectively.
+ (font-lock-mode
+ (with-no-warnings
+ (font-lock-fontify-buffer)))))
+
+(defun dash--turn-on-fontify-mode ()
+ "Enable `dash-fontify-mode' if in an Emacs Lisp buffer."
+ (when (derived-mode-p #'emacs-lisp-mode)
+ (dash-fontify-mode)))
+
+;;;###autoload
+(define-globalized-minor-mode global-dash-fontify-mode
+ dash-fontify-mode dash--turn-on-fontify-mode
+ :group 'dash)
+
+(defcustom dash-enable-fontlock nil
+ "If non-nil, fontify Dash macro calls and special variables."
+ :group 'dash
+ :set (lambda (sym val)
+ (set-default sym val)
+ (global-dash-fontify-mode (if val 1 0)))
+ :type 'boolean)
+
+(make-obsolete-variable
+ 'dash-enable-fontlock #'global-dash-fontify-mode "2.18.0")
+
+(define-obsolete-function-alias
+ 'dash-enable-font-lock #'global-dash-fontify-mode "2.18.0")
+
+;;; Info
+
+(defvar dash--info-doc-spec '("(dash) Index" nil "^ -+ .*: " "\\( \\|$\\)")
+ "The Dash :doc-spec entry for `info-lookup-alist'.
+It is based on that for `emacs-lisp-mode'.")
+
+(defun dash--info-elisp-docs ()
+ "Return the `emacs-lisp-mode' symbol docs from `info-lookup-alist'.
+Specifically, return the cons containing their
+`info-lookup->doc-spec' so that we can modify it."
+ (defvar info-lookup-alist)
+ (nthcdr 3 (assq #'emacs-lisp-mode (cdr (assq 'symbol info-lookup-alist)))))
+
+;;;###autoload
+(defun dash-register-info-lookup ()
+ "Register the Dash Info manual with `info-lookup-symbol'.
+This allows Dash symbols to be looked up with \\[info-lookup-symbol]."
+ (interactive)
+ (require 'info-look)
+ (let ((docs (dash--info-elisp-docs)))
+ (setcar docs (append (car docs) (list dash--info-doc-spec)))
+ (info-lookup-reset)))
+
+(defun dash-unload-function ()
+ "Remove Dash from `info-lookup-alist'.
+Used by `unload-feature', which see."
+ (let ((docs (and (featurep 'info-look)
+ (dash--info-elisp-docs))))
+ (when (member dash--info-doc-spec (car docs))
+ (setcar docs (remove dash--info-doc-spec (car docs)))
+ (info-lookup-reset)))
+ nil)
+
+(provide 'dash)
+;;; dash.el ends here