;;; 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: 1.6
+;; Version: 2.3
;; Package: seq
;; Maintainer: emacs-devel@gnu.org
;; the sequence as their second argument. All other functions take
;; the sequence as their first argument.
;;
+;; While seq.el version 1.8 is in GNU ELPA for convenience, seq.el
+;; version 2.0 requires Emacs>=25.1.
+;;
+;; seq.el can be extended to support new type of sequences. Here are
+;; the generic functions that must be implemented by new seq types:
+;; - `seq-elt'
+;; - `seq-length'
+;; - `seq-do'
+;; - `seqp'
+;; - `seq-subseq'
+;; - `seq-into-sequence'
+;; - `seq-copy'
+;; - `seq-into'
+;;
;; All functions are tested in test/automated/seq-tests.el
-;;; TODO:
-
-;; - Add a pcase macro named using `pcase-defmacro' that `seq-let'
-;; - could wrap.
-
;;; Code:
+(eval-when-compile (require 'cl-generic))
+(require 'cl-lib) ;; for cl-subseq
+
(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 SEQUENCE, in turn.
-Evaluate BODY with VAR bound to each element of SEQ, in turn.
+Similar to `dolist' but can be applied to lists, strings, and vectors.
-\(fn (VAR SEQ) BODY...)"
+\(fn (VAR SEQUENCE) 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)))))
-
-(defmacro seq-let (args seq &rest body)
- "Bind the variables in ARGS to the elements of SEQ then evaluate BODY."
+ `(seq-do (lambda (,(car spec))
+ ,@body)
+ ,(cadr spec)))
+
+(pcase-defmacro seq (&rest patterns)
+ "Build a `pcase' pattern that matches elements of SEQUENCE.
+
+The `pcase' pattern will match each element of PATTERNS against the
+corresponding element of SEQUENCE.
+
+Extra elements of the sequence are ignored if fewer PATTERNS are
+given, and the match does not fail."
+ `(and (pred seqp)
+ ,@(seq--make-pcase-bindings patterns)))
+
+(defmacro seq-let (args sequence &rest body)
+ "Bind the variables in ARGS to the elements of SEQUENCE, then evaluate BODY.
+
+ARGS can also include the `&rest' marker followed by a variable
+name to be bound to the rest of SEQUENCE."
(declare (indent 2) (debug t))
- (let ((seq-var (make-symbol "seq")))
- `(let* ((,seq-var ,seq)
- ,@(seq--make-bindings args seq-var))
- ,@body)))
+ `(pcase-let ((,(seq--make-pcase-patterns args) ,sequence))
+ ,@body))
+\f
+
+;;; Basic seq functions that have to be implemented by new sequence types
+(cl-defgeneric seq-elt (sequence n)
+ "Return Nth element of SEQUENCE."
+ (elt sequence n))
+
+;; Default gv setters for `seq-elt'.
+;; It can be a good idea for new sequence implementations to provide a
+;; "gv-setter" for `seq-elt'.
+(cl-defmethod (setf seq-elt) (store (sequence array) n)
+ (aset sequence n store))
+
+(cl-defmethod (setf seq-elt) (store (sequence cons) n)
+ (setcar (nthcdr n sequence) store))
+
+(cl-defgeneric seq-length (sequence)
+ "Return the number of elements of SEQUENCE."
+ (length sequence))
+
+(cl-defgeneric seq-do (function sequence)
+ "Apply FUNCTION to each element of SEQUENCE, presumably for side effects.
+Return SEQUENCE."
+ (mapc function sequence))
-(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.
+(defalias 'seq-each #'seq-do)
+
+(cl-defgeneric seqp (sequence)
+ "Return non-nil if SEQUENCE is a sequence, nil otherwise."
+ (sequencep sequence))
+
+(cl-defgeneric seq-copy (sequence)
+ "Return a shallow copy of SEQUENCE."
+ (copy-sequence sequence))
+
+(cl-defgeneric seq-subseq (sequence start &optional end)
+ "Return the sequence of elements of SEQUENCE from START to END.
+END is inclusive.
+
+If END is omitted, it defaults to the length of the sequence. If
+START or END is negative, it counts from the end. Signal an
+error if START or END are outside of the sequence (i.e too large
+if positive or too small if negative)."
+ (cl-subseq sequence start end))
+
+\f
+(cl-defgeneric seq-map (function sequence)
+ "Return the result of applying FUNCTION to each element of SEQUENCE."
+ (let (result)
+ (seq-do (lambda (elt)
+ (push (funcall function elt) result))
+ sequence)
+ (nreverse result)))
+
+;; faster implementation for sequences (sequencep)
+(cl-defmethod seq-map (function (sequence sequence))
+ (mapcar function sequence))
+
+(cl-defgeneric seq-mapn (function sequence &rest sequences)
+ "Like `seq-map' but FUNCTION is mapped over all SEQUENCES.
+The arity of FUNCTION must match the number of SEQUENCES, and the
+mapping stops on the shortest sequence.
+Return a list of the results.
+
+\(fn FUNCTION SEQUENCES...)"
+ (let ((result nil)
+ (sequences (seq-map (lambda (s) (seq-into s 'list))
+ (cons sequence sequences))))
+ (while (not (memq nil sequences))
+ (push (apply function (seq-map #'car sequences)) result)
+ (setq sequences (seq-map #'cdr sequences)))
+ (nreverse result)))
-If N is a negative integer or zero, SEQ is returned."
+(cl-defgeneric seq-drop (sequence n)
+ "Remove the first N elements of SEQUENCE and return the result.
+The result is a sequence of the same type as SEQUENCE.
+
+If N is a negative integer or zero, SEQUENCE 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)))))
+ sequence
+ (let ((length (seq-length sequence)))
+ (seq-subseq sequence (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.
+(cl-defgeneric seq-take (sequence n)
+ "Take the first N elements of SEQUENCE and return the result.
+The result is a sequence of the same type as SEQUENCE.
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."
+ (seq-subseq sequence 0 (min (max n 0) (seq-length sequence))))
+
+(cl-defgeneric seq-drop-while (pred sequence)
+ "Remove the successive elements of SEQUENCE for which PRED returns non-nil.
+PRED is a function of one argument. The result is a sequence of
+the same type as SEQUENCE."
+ (seq-drop sequence (seq--count-successive pred sequence)))
+
+(cl-defgeneric seq-take-while (pred sequence)
+ "Take the successive elements of SEQUENCE for which PRED returns non-nil.
+PRED is a function of one argument. The result is a sequence of
+the same type as SEQUENCE."
+ (seq-take sequence (seq--count-successive pred sequence)))
+
+(cl-defgeneric seq-empty-p (sequence)
+ "Return non-nil if the SEQUENCE is empty, nil otherwise."
+ (= 0 (seq-length sequence)))
+
+(cl-defgeneric seq-sort (pred sequence)
+ "Sort SEQUENCE using PRED as comparison function.
+The result is a sequence of the same type as SEQUENCE."
+ (let ((result (seq-sort pred (append sequence nil))))
+ (seq-into result (type-of sequence))))
+
+(cl-defmethod seq-sort (pred (list list))
+ (sort (seq-copy list) pred))
+
+(cl-defgeneric seq-reverse (sequence)
+ "Return a sequence with elements of SEQUENCE in reverse order."
+ (let ((result '()))
+ (seq-map (lambda (elt)
+ (push elt result))
+ sequence)
+ (seq-into result (type-of sequence))))
+
+;; faster implementation for sequences (sequencep)
+(cl-defmethod seq-reverse ((sequence sequence))
+ (reverse sequence))
+
+(cl-defgeneric seq-concatenate (type &rest sequences)
+ "Concatenate SEQUENCES into a single sequence of type TYPE.
+TYPE must be one of following symbols: vector, string or list.
+
+\n(fn TYPE SEQUENCE...)"
+ (apply #'cl-concatenate type (seq-map #'seq-into-sequence sequences)))
+
+(cl-defgeneric seq-into-sequence (sequence)
+ "Convert SEQUENCE into a sequence.
+
+The default implementation is to signal an error if SEQUENCE is not a
+sequence, specific functions should be implemented for new types
+of sequence."
+ (unless (sequencep sequence)
+ (error "Cannot convert %S into a sequence" sequence))
+ sequence)
+
+(cl-defgeneric seq-into (sequence type)
+ "Concatenate the elements of SEQUENCE into a sequence of type TYPE.
+TYPE can be one of the following symbols: vector, string or
+list."
+ (pcase type
+ (`vector (vconcat sequence))
+ (`string (concat sequence))
+ (`list (append sequence nil))
+ (_ (error "Not a sequence type name: %S" type))))
+
+(cl-defgeneric seq-filter (pred sequence)
+ "Return a list of all the elements for which (PRED element) is non-nil in SEQUENCE."
(let ((exclude (make-symbol "exclude")))
(delq exclude (seq-map (lambda (elt)
(if (funcall pred elt)
elt
exclude))
- seq))))
+ sequence))))
-(defun seq-remove (pred seq)
- "Return a list of all the elements for which (PRED element) is nil in SEQ."
+(cl-defgeneric seq-remove (pred sequence)
+ "Return a list of all the elements for which (PRED element) is nil in SEQUENCE."
(seq-filter (lambda (elt) (not (funcall pred elt)))
- seq))
+ sequence))
-(defun seq-reduce (function seq initial-value)
- "Reduce the function FUNCTION across SEQ, starting with INITIAL-VALUE.
+(cl-defgeneric seq-reduce (function sequence initial-value)
+ "Reduce the function FUNCTION across SEQUENCE, 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.
+first element of SEQUENCE, then calling FUNCTION with that result and
+the second element of SEQUENCE, then with that result and the third
+element of SEQUENCE, etc.
-If SEQ is empty, return INITIAL-VALUE and FUNCTION is not called."
- (if (seq-empty-p seq)
+If SEQUENCE is empty, return INITIAL-VALUE and FUNCTION is not called."
+ (if (seq-empty-p sequence)
initial-value
(let ((acc initial-value))
- (seq-doseq (elt seq)
+ (seq-doseq (elt sequence)
(setq acc (funcall function acc elt)))
acc)))
-(defun seq-some-p (pred seq)
- "Return any element for which (PRED element) is non-nil in SEQ, nil otherwise."
+(cl-defgeneric seq-every-p (pred sequence)
+ "Return non-nil if (PRED element) is non-nil for all elements of SEQUENCE."
(catch 'seq--break
- (seq-doseq (elt seq)
- (when (funcall pred elt)
- (throw 'seq--break elt)))
- nil))
-
-(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)
+ (seq-doseq (elt sequence)
(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."
+(cl-defgeneric seq-some (pred sequence)
+ "Return the first value for which if (PRED element) is non-nil for in SEQUENCE."
+ (catch 'seq--break
+ (seq-doseq (elt sequence)
+ (let ((result (funcall pred elt)))
+ (when result
+ (throw 'seq--break result))))
+ nil))
+
+(cl-defgeneric seq-find (pred sequence &optional default)
+ "Return the first element for which (PRED element) is non-nil in SEQUENCE.
+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 sequence)
+ (when (funcall pred elt)
+ (throw 'seq--break elt)))
+ default))
+
+(cl-defgeneric seq-count (pred sequence)
+ "Return the number of elements for which (PRED element) is non-nil in SEQUENCE."
(let ((count 0))
- (seq-doseq (elt seq)
+ (seq-doseq (elt sequence)
(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-p (seq elt &optional testfn)
- "Return the first element in SEQ that equals to ELT.
+(cl-defgeneric seq-contains (sequence elt &optional testfn)
+ "Return the first element in SEQUENCE that is equal to ELT.
Equality is defined by TESTFN if non-nil or by `equal' if nil."
- (seq-some-p (lambda (e)
- (funcall (or testfn #'equal) elt e))
- seq))
+ (seq-some (lambda (e)
+ (funcall (or testfn #'equal) elt e))
+ sequence))
-(defun seq-uniq (seq &optional testfn)
- "Return a list of the elements of SEQ with duplicates removed.
+(cl-defgeneric seq-position (sequence elt &optional testfn)
+ "Return the index of the first element in SEQUENCE 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 sequence)
+ (when (funcall (or testfn #'equal) e elt)
+ (throw 'seq--break index))
+ (setq index (1+ index)))
+ nil)))
+
+(cl-defgeneric seq-uniq (sequence &optional testfn)
+ "Return a list of the elements of SEQUENCE with duplicates removed.
TESTFN is used to compare elements, or `equal' if TESTFN is nil."
(let ((result '()))
- (seq-doseq (elt seq)
- (unless (seq-contains-p result elt testfn)
+ (seq-doseq (elt sequence)
+ (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.
+(cl-defgeneric seq-mapcat (function sequence &optional type)
+ "Concatenate the result of applying FUNCTION to each element of SEQUENCE.
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)))
+ (seq-map function sequence)))
-(defun seq-partition (seq n)
- "Return a list of the elements of SEQ grouped into sub-sequences of length N.
+(cl-defgeneric seq-partition (sequence n)
+ "Return a list of the elements of SEQUENCE 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)))
+ (while (not (seq-empty-p sequence))
+ (push (seq-take sequence n) result)
+ (setq sequence (seq-drop sequence n)))
(nreverse result))))
-(defun seq-intersection (seq1 seq2 &optional testfn)
- "Return a list of the elements that appear in both SEQ1 and SEQ2.
+(cl-defgeneric seq-intersection (sequence1 sequence2 &optional testfn)
+ "Return a list of the elements that appear in both SEQUENCE1 and SEQUENCE2.
Equality is defined by TESTFN if non-nil or by `equal' if nil."
(seq-reduce (lambda (acc elt)
- (if (seq-contains-p seq2 elt testfn)
+ (if (seq-contains sequence2 elt testfn)
(cons elt acc)
acc))
- (seq-reverse seq1)
+ (seq-reverse sequence1)
'()))
-(defun seq-difference (seq1 seq2 &optional testfn)
- "Return a list of th elements that appear in SEQ1 but not in SEQ2.
+(cl-defgeneric seq-difference (sequence1 sequence2 &optional testfn)
+ "Return a list of the elements that appear in SEQUENCE1 but not in SEQUENCE2.
Equality is defined by TESTFN if non-nil or by `equal' if nil."
(seq-reduce (lambda (acc elt)
- (if (not (seq-contains-p seq2 elt testfn))
+ (if (not (seq-contains sequence2 elt testfn))
(cons elt acc)
acc))
- (seq-reverse seq1)
+ (seq-reverse sequence1)
'()))
-(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
+(cl-defgeneric seq-group-by (function sequence)
+ "Apply FUNCTION to each element of SEQUENCE.
+Separate the elements of SEQUENCE into an alist using the results as
keys. Keys are compared using `equal'."
(seq-reduce
(lambda (acc elt)
(setcdr cell (push elt (cdr cell)))
(push (list key elt) acc))
acc))
- (seq-reverse seq)
+ (seq-reverse sequence)
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--drop-list (list n)
- "Return a list from LIST without its first N elements.
-This is an optimization for lists in `seq-drop'."
+(cl-defgeneric seq-min (sequence)
+ "Return the smallest element of SEQUENCE.
+SEQUENCE must be a sequence of numbers or markers."
+ (apply #'min (seq-into sequence 'list)))
+
+(cl-defgeneric seq-max (sequence)
+ "Return the largest element of SEQUENCE.
+SEQUENCE must be a sequence of numbers or markers."
+ (apply #'max (seq-into sequence 'list)))
+
+(defun seq--count-successive (pred sequence)
+ "Return the number of successive elements for which (PRED element) is non-nil in SEQUENCE."
+ (let ((n 0)
+ (len (seq-length sequence)))
+ (while (and (< n len)
+ (funcall pred (seq-elt sequence 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)))
+ (_
+ (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 (seqp elt)
+ (seq--make-pcase-patterns elt)
+ elt))
+ args)))
+
+;; TODO: make public?
+(defun seq--elt-safe (sequence n)
+ "Return element of SEQUENCE at the index N.
+If no element is found, return nil."
+ (ignore-errors (seq-elt sequence n)))
+\f
+
+;;; Optimized implementations for lists
+
+(cl-defmethod seq-drop ((list list) n)
+ "Optimized implementation of `seq-drop' for lists."
(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'."
+(cl-defmethod seq-take ((list list) n)
+ "Optimized implementation of `seq-take' for lists."
(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'."
+(cl-defmethod seq-drop-while (pred (list list))
+ "Optimized implementation of `seq-drop-while' for lists."
(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))
+(cl-defmethod seq-empty-p ((list list))
+ "Optimized implementation of `seq-empty-p' for lists."
+ (null list))
+\f
(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\\>")))
-(defun seq--make-bindings (args seq &optional bindings)
- "Return a list of bindings of the variables in ARGS to the elements of SEQ.
-if BINDINGS is non-nil, append new bindings to it, and
-return BINDINGS."
- (let ((index 0)
- (rest-bound nil))
- (seq-doseq (name args)
- (unless rest-bound
- (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-bound 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)))
-
-(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-to-list 'emacs-lisp-mode-hook #'seq--activate-font-lock-keywords))
+ (add-hook 'emacs-lisp-mode-hook #'seq--activate-font-lock-keywords))
(provide 'seq)
;;; seq.el ends here