;;; seq.el --- Sequence manipulation functions -*- lexical-binding: t -*-
-;; Copyright (C) 2014-2015 Free Software Foundation, Inc.
+;; Copyright (C) 2014-2016 Free Software Foundation, Inc.
;; Author: Nicolas Petton <nicolas@petton.fr>
;; Keywords: sequences
-;; Version: 1.11
+;; Version: 2.12
;; Package: seq
;; Maintainer: emacs-devel@gnu.org
;; function as argument take the function as their first argument and
;; the sequence as their second argument. All other functions take
;; the sequence as their first argument.
-;;
-;; All functions are tested in test/automated/seq-tests.el
;;; Code:
-(defmacro seq-doseq (spec &rest body)
- "Loop over a sequence.
-Similar to `dolist' but can be applied to lists, strings, and vectors.
-
-Evaluate BODY with VAR bound to each element of SEQ, in turn.
-
-\(fn (VAR SEQ) BODY...)"
- (declare (indent 1) (debug ((symbolp form &optional form) body)))
- (let ((length (make-symbol "length"))
- (seq (make-symbol "seq"))
- (index (make-symbol "index")))
- `(let* ((,seq ,(cadr spec))
- (,length (if (listp ,seq) nil (seq-length ,seq)))
- (,index (if ,length 0 ,seq)))
- (while (if ,length
- (< ,index ,length)
- (consp ,index))
- (let ((,(car spec) (if ,length
- (prog1 (seq-elt ,seq ,index)
- (setq ,index (+ ,index 1)))
- (pop ,index))))
- ,@body)))))
-
-(if (fboundp 'pcase-defmacro)
- ;; Implementation of `seq-let' based on a `pcase'
- ;; pattern. Requires Emacs>=25.1.
- (progn
- (pcase-defmacro seq (&rest args)
- "pcase pattern matching sequence elements.
-Matches if the object is a sequence (list, string or vector), and
-binds each element of ARGS to the corresponding element of the
-sequence."
- `(and (pred seq-p)
- ,@(seq--make-pcase-bindings args)))
-
- (defmacro seq-let (args seq &rest body)
- "Bind the variables in ARGS to the elements of SEQ then evaluate BODY.
-
-ARGS can also include the `&rest' marker followed by a variable
-name to be bound to the rest of SEQ."
- (declare (indent 2) (debug t))
- `(pcase-let ((,(seq--make-pcase-patterns args) ,seq))
- ,@body)))
-
- ;; Implementation of `seq-let' compatible with Emacs<25.1.
- (defmacro seq-let (args seq &rest body)
- "Bind the variables in ARGS to the elements of SEQ then evaluate BODY.
-
-ARGS can also include the `&rest' marker followed by a variable
-name to be bound to the rest of SEQ."
- (declare (indent 2) (debug t))
- (let ((seq-var (make-symbol "seq")))
- `(let* ((,seq-var ,seq)
- ,@(seq--make-bindings args seq-var))
- ,@body))))
-
-(defun seq-drop (seq n)
- "Return a subsequence of SEQ without its first N elements.
-The result is a sequence of the same type as SEQ.
-
-If N is a negative integer or zero, SEQ is returned."
- (if (<= n 0)
- seq
- (if (listp seq)
- (seq--drop-list seq n)
- (let ((length (seq-length seq)))
- (seq-subseq seq (min n length) length)))))
-
-(defun seq-take (seq n)
- "Return a subsequence of SEQ with its first N elements.
-The result is a sequence of the same type as SEQ.
-
-If N is a negative integer or zero, an empty sequence is
-returned."
- (if (listp seq)
- (seq--take-list seq n)
- (seq-subseq seq 0 (min (max n 0) (seq-length seq)))))
-
-(defun seq-drop-while (pred seq)
- "Return a sequence from the first element for which (PRED element) is nil in SEQ.
-The result is a sequence of the same type as SEQ."
- (if (listp seq)
- (seq--drop-while-list pred seq)
- (seq-drop seq (seq--count-successive pred seq))))
-
-(defun seq-take-while (pred seq)
- "Return the successive elements for which (PRED element) is non-nil in SEQ.
-The result is a sequence of the same type as SEQ."
- (if (listp seq)
- (seq--take-while-list pred seq)
- (seq-take seq (seq--count-successive pred seq))))
-
-(defun seq-filter (pred seq)
- "Return a list of all the elements for which (PRED element) is non-nil in SEQ."
- (let ((exclude (make-symbol "exclude")))
- (delq exclude (seq-map (lambda (elt)
- (if (funcall pred elt)
- elt
- exclude))
- seq))))
-
-(defun seq-remove (pred seq)
- "Return a list of all the elements for which (PRED element) is nil in SEQ."
- (seq-filter (lambda (elt) (not (funcall pred elt)))
- seq))
-
-(defun seq-reduce (function seq initial-value)
- "Reduce the function FUNCTION across SEQ, starting with INITIAL-VALUE.
-
-Return the result of calling FUNCTION with INITIAL-VALUE and the
-first element of SEQ, then calling FUNCTION with that result and
-the second element of SEQ, then with that result and the third
-element of SEQ, etc.
-
-If SEQ is empty, return INITIAL-VALUE and FUNCTION is not called."
- (if (seq-empty-p seq)
- initial-value
- (let ((acc initial-value))
- (seq-doseq (elt seq)
- (setq acc (funcall function acc elt)))
- acc)))
-
-(defun seq-some (pred seq)
- "Return the first value for which if (PRED element) is non-nil for in SEQ."
- (catch 'seq--break
- (seq-doseq (elt seq)
- (let ((result (funcall pred elt)))
- (when result
- (throw 'seq--break result))))
- nil))
-
-(defun seq-find (pred seq &optional default)
- "Return the first element for which (PRED element) is non-nil in SEQ.
-If no element is found, return DEFAULT.
-
-Note that `seq-find' has an ambiguity if the found element is
-identical to DEFAULT, as it cannot be known if an element was
-found or not."
- (catch 'seq--break
- (seq-doseq (elt seq)
- (when (funcall pred elt)
- (throw 'seq--break elt)))
- default))
-
-(defun seq-every-p (pred seq)
- "Return non-nil if (PRED element) is non-nil for all elements of the sequence SEQ."
- (catch 'seq--break
- (seq-doseq (elt seq)
- (or (funcall pred elt)
- (throw 'seq--break nil)))
- t))
-
-(defun seq-count (pred seq)
- "Return the number of elements for which (PRED element) is non-nil in SEQ."
- (let ((count 0))
- (seq-doseq (elt seq)
- (when (funcall pred elt)
- (setq count (+ 1 count))))
- count))
-
-(defun seq-empty-p (seq)
- "Return non-nil if the sequence SEQ is empty, nil otherwise."
- (if (listp seq)
- (null seq)
- (= 0 (seq-length seq))))
-
-(defun seq-sort (pred seq)
- "Return a sorted sequence comparing using PRED the elements of SEQ.
-The result is a sequence of the same type as SEQ."
- (if (listp seq)
- (sort (seq-copy seq) pred)
- (let ((result (seq-sort pred (append seq nil))))
- (seq-into result (type-of seq)))))
-
-(defun seq-contains (seq elt &optional testfn)
- "Return the first element in SEQ that equals to ELT.
-Equality is defined by TESTFN if non-nil or by `equal' if nil."
- (seq-some (lambda (e)
- (funcall (or testfn #'equal) elt e))
- seq))
-
-(defun seq-position (seq elt &optional testfn)
- "Return the index of the first element in SEQ that is equal to ELT.
-Equality is defined by TESTFN if non-nil or by `equal' if nil."
- (let ((index 0))
- (catch 'seq--break
- (seq-doseq (e seq)
- (when (funcall (or testfn #'equal) e elt)
- (throw 'seq--break index))
- (setq index (1+ index)))
- nil)))
-
-(defun seq-uniq (seq &optional testfn)
- "Return a list of the elements of SEQ with duplicates removed.
-TESTFN is used to compare elements, or `equal' if TESTFN is nil."
- (let ((result '()))
- (seq-doseq (elt seq)
- (unless (seq-contains result elt testfn)
- (setq result (cons elt result))))
- (nreverse result)))
-
-(defun seq-subseq (seq start &optional end)
- "Return the subsequence of SEQ from START to END.
-If END is omitted, it defaults to the length of the sequence.
-If START or END is negative, it counts from the end."
- (cond ((or (stringp seq) (vectorp seq)) (substring seq start end))
- ((listp seq)
- (let (len (errtext (format "Bad bounding indices: %s, %s" start end)))
- (and end (< end 0) (setq end (+ end (setq len (seq-length seq)))))
- (if (< start 0) (setq start (+ start (or len (setq len (seq-length seq))))))
- (when (> start 0)
- (setq seq (nthcdr (1- start) seq))
- (or seq (error "%s" errtext))
- (setq seq (cdr seq)))
- (if end
- (let ((res nil))
- (while (and (>= (setq end (1- end)) start) seq)
- (push (pop seq) res))
- (or (= (1+ end) start) (error "%s" errtext))
- (nreverse res))
- (seq-copy seq))))
- (t (error "Unsupported sequence: %s" seq))))
-
-(defun seq-concatenate (type &rest seqs)
- "Concatenate, into a sequence of type TYPE, the sequences SEQS.
-TYPE must be one of following symbols: vector, string or list.
-
-\n(fn TYPE SEQUENCE...)"
- (pcase type
- (`vector (apply #'vconcat seqs))
- (`string (apply #'concat seqs))
- (`list (apply #'append (append seqs '(nil))))
- (t (error "Not a sequence type name: %S" type))))
-
-(defun seq-mapcat (function seq &optional type)
- "Concatenate the result of applying FUNCTION to each element of SEQ.
-The result is a sequence of type TYPE, or a list if TYPE is nil."
- (apply #'seq-concatenate (or type 'list)
- (seq-map function seq)))
-
-(defun seq-partition (seq n)
- "Return a list of the elements of SEQ grouped into sub-sequences of length N.
-The last sequence may contain less than N elements. If N is a
-negative integer or 0, nil is returned."
- (unless (< n 1)
- (let ((result '()))
- (while (not (seq-empty-p seq))
- (push (seq-take seq n) result)
- (setq seq (seq-drop seq n)))
- (nreverse result))))
-
-(defun seq-intersection (seq1 seq2 &optional testfn)
- "Return a list of the elements that appear in both SEQ1 and SEQ2.
-Equality is defined by TESTFN if non-nil or by `equal' if nil."
- (seq-reduce (lambda (acc elt)
- (if (seq-contains seq2 elt testfn)
- (cons elt acc)
- acc))
- (seq-reverse seq1)
- '()))
-
-(defun seq-difference (seq1 seq2 &optional testfn)
- "Return a list of the elements that appear in SEQ1 but not in SEQ2.
-Equality is defined by TESTFN if non-nil or by `equal' if nil."
- (seq-reduce (lambda (acc elt)
- (if (not (seq-contains seq2 elt testfn))
- (cons elt acc)
- acc))
- (seq-reverse seq1)
- '()))
-
-(defun seq-group-by (function seq)
- "Apply FUNCTION to each element of SEQ.
-Separate the elements of SEQ into an alist using the results as
-keys. Keys are compared using `equal'."
- (seq-reduce
- (lambda (acc elt)
- (let* ((key (funcall function elt))
- (cell (assoc key acc)))
- (if cell
- (setcdr cell (push elt (cdr cell)))
- (push (list key elt) acc))
- acc))
- (seq-reverse seq)
- nil))
-
-(defalias 'seq-reverse
- (if (ignore-errors (reverse [1 2]))
- #'reverse
- (lambda (seq)
- "Return the reversed copy of list, vector, or string SEQ.
-See also the function `nreverse', which is used more often."
- (let ((result '()))
- (seq-map (lambda (elt) (push elt result))
- seq)
- (if (listp seq)
- result
- (seq-into result (type-of seq)))))))
-
-(defun seq-into (seq type)
- "Convert the sequence SEQ into a sequence of type TYPE.
-TYPE can be one of the following symbols: vector, string or list."
- (pcase type
- (`vector (vconcat seq))
- (`string (concat seq))
- (`list (append seq nil))
- (t (error "Not a sequence type name: %S" type))))
-
-(defun seq-min (seq)
- "Return the smallest element of SEQ.
-SEQ must be a sequence of numbers or markers."
- (apply #'min (seq-into seq 'list)))
-
-(defun seq-max (seq)
- "Return the largest element of SEQ.
-SEQ must be a sequence of numbers or markers."
- (apply #'max (seq-into seq 'list)))
-
-(defun seq--drop-list (list n)
- "Return a list from LIST without its first N elements.
-This is an optimization for lists in `seq-drop'."
- (while (and list (> n 0))
- (setq list (cdr list)
- n (1- n)))
- list)
-
-(defun seq--take-list (list n)
- "Return a list from LIST made of its first N elements.
-This is an optimization for lists in `seq-take'."
- (let ((result '()))
- (while (and list (> n 0))
- (setq n (1- n))
- (push (pop list) result))
- (nreverse result)))
-
-(defun seq--drop-while-list (pred list)
- "Return a list from the first element for which (PRED element) is nil in LIST.
-This is an optimization for lists in `seq-drop-while'."
- (while (and list (funcall pred (car list)))
- (setq list (cdr list)))
- list)
-
-(defun seq--take-while-list (pred list)
- "Return the successive elements for which (PRED element) is non-nil in LIST.
-This is an optimization for lists in `seq-take-while'."
- (let ((result '()))
- (while (and list (funcall pred (car list)))
- (push (pop list) result))
- (nreverse result)))
-
-(defun seq--count-successive (pred seq)
- "Return the number of successive elements for which (PRED element) is non-nil in SEQ."
- (let ((n 0)
- (len (seq-length seq)))
- (while (and (< n len)
- (funcall pred (seq-elt seq n)))
- (setq n (+ 1 n)))
- n))
-
-(defun seq--make-pcase-bindings (args)
- "Return a list of bindings of the variables in ARGS to the elements of a sequence."
- (let ((bindings '())
- (index 0)
- (rest-marker nil))
- (seq-doseq (name args)
- (unless rest-marker
- (pcase name
- (`&rest
- (progn (push `(app (pcase--flip seq-drop ,index)
- ,(seq--elt-safe args (1+ index)))
- bindings)
- (setq rest-marker t)))
- (t
- (push `(app (pcase--flip seq--elt-safe ,index) ,name) bindings))))
- (setq index (1+ index)))
- bindings))
-
-(defun seq--make-pcase-patterns (args)
- "Return a list of `(seq ...)' pcase patterns from the argument list ARGS."
- (cons 'seq
- (seq-map (lambda (elt)
- (if (seq-p elt)
- (seq--make-pcase-patterns elt)
- elt))
- args)))
-
-;; Helper function for the Backward-compatible version of `seq-let'
-;; for Emacs<25.1.
-(defun seq--make-bindings (args seq &optional bindings)
- "Return a list of bindings of the variables in ARGS to the elements of a sequence.
-if BINDINGS is non-nil, append new bindings to it, and return
-BINDINGS."
- (let ((index 0)
- (rest-marker nil))
- (seq-doseq (name args)
- (unless rest-marker
- (pcase name
- ((pred seq-p)
- (setq bindings (seq--make-bindings (seq--elt-safe args index)
- `(seq--elt-safe ,seq ,index)
- bindings)))
- (`&rest
- (progn (push `(,(seq--elt-safe args (1+ index))
- (seq-drop ,seq ,index))
- bindings)
- (setq rest-marker t)))
- (t
- (push `(,name (seq--elt-safe ,seq ,index)) bindings))))
- (setq index (1+ index)))
- bindings))
-
-(defun seq--elt-safe (seq n)
- "Return element of SEQ at the index N.
-If no element is found, return nil."
- (when (or (listp seq)
- (and (sequencep seq)
- (> (seq-length seq) n)))
- (seq-elt seq n)))
-
-(defun seq--activate-font-lock-keywords ()
- "Activate font-lock keywords for some symbols defined in seq."
- (font-lock-add-keywords 'emacs-lisp-mode
- '("\\<seq-doseq\\>" "\\<seq-let\\>")))
-
-(defalias 'seq-copy #'copy-sequence)
-(defalias 'seq-elt #'elt)
-(defalias 'seq-length #'length)
-(defalias 'seq-do #'mapc)
-(defalias 'seq-each #'seq-do)
-(defalias 'seq-map #'mapcar)
-(defalias 'seq-p #'sequencep)
-
-(unless (fboundp 'elisp--font-lock-flush-elisp-buffers)
- ;; In Emacsā„25, (via elisp--font-lock-flush-elisp-buffers and a few others)
- ;; we automatically highlight macros.
- (add-hook 'emacs-lisp-mode-hook #'seq--activate-font-lock-keywords))
+(if (version< emacs-version "25")
+ (require 'seq-24)
+ (require 'seq-25))
(provide 'seq)
;;; seq.el ends here