diff options
Diffstat (limited to 'lisp/emacs-lisp/subr-x.el')
| -rw-r--r-- | lisp/emacs-lisp/subr-x.el | 144 |
1 files changed, 85 insertions, 59 deletions
diff --git a/lisp/emacs-lisp/subr-x.el b/lisp/emacs-lisp/subr-x.el index 9cd793d05c5..bd7c3c82f97 100644 --- a/lisp/emacs-lisp/subr-x.el +++ b/lisp/emacs-lisp/subr-x.el @@ -87,15 +87,15 @@ threading." (defsubst hash-table-keys (hash-table) "Return a list of keys in HASH-TABLE." - (cl-loop for k being the hash-keys of hash-table collect k)) + (let ((keys nil)) + (maphash (lambda (k _) (push k keys)) hash-table) + keys)) (defsubst hash-table-values (hash-table) "Return a list of values in HASH-TABLE." - (cl-loop for v being the hash-values of hash-table collect v)) - -(defsubst string-empty-p (string) - "Check whether STRING is empty." - (string= string "")) + (let ((values nil)) + (maphash (lambda (_ v) (push v values)) hash-table) + values)) (defsubst string-join (strings &optional separator) "Join all STRINGS using SEPARATOR. @@ -107,13 +107,18 @@ characters; nil stands for the empty string." ;;;###autoload (defun string-truncate-left (string length) - "Truncate STRING to LENGTH, replacing initial surplus with \"...\"." + "If STRING is longer than LENGTH, return a truncated version. +When truncating, \"...\" is always prepended to the string, so +the resulting string may be longer than the original if LENGTH is +3 or smaller." (let ((strlen (length string))) (if (<= strlen length) string (setq length (max 0 (- length 3))) - (concat "..." (substring string (max 0 (- strlen 1 length))))))) + (concat "..." (substring string (min (1- strlen) + (max 0 (- strlen length)))))))) +;;;###autoload (defsubst string-blank-p (string) "Check whether STRING is either empty or only whitespace. The following characters count as whitespace here: space, tab, newline and @@ -167,9 +172,13 @@ non-nil, return the last LENGTH characters instead. If CODING-SYSTEM is non-nil, STRING will be encoded before limiting, and LENGTH is interpreted as the number of bytes to limit the string to. The result will be a unibyte string that is -shorter than LENGTH, but will not contain \"partial\" characters, -even if CODING-SYSTEM encodes characters with several bytes per -character. +shorter than LENGTH, but will not contain \"partial\" +characters (or glyphs), even if CODING-SYSTEM encodes characters +with several bytes per character. If the coding system specifies +prefix like the byte order mark (aka \"BOM\") or a shift-in sequence, +their bytes will be normally counted as part of LENGTH. This is +the case, for instance, with `utf-16'. If this isn't desired, use a +coding system that doesn't specify a BOM, like `utf-16le' or `utf-16be'. When shortening strings for display purposes, `truncate-string-to-width' is almost always a better alternative @@ -177,34 +186,55 @@ than this function." (unless (natnump length) (signal 'wrong-type-argument (list 'natnump length))) (if coding-system - (let ((result nil) - (result-length 0) - (index (if end (1- (length string)) 0))) - ;; FIXME: This implementation, which uses encode-coding-char - ;; to encode the string one character at a time, is in general - ;; incorrect: coding-systems that produce prefix or suffix - ;; bytes, such as ISO-2022-based or UTF-8/16 with BOM, will - ;; produce those bytes for each character, instead of just - ;; once for the entire string. encode-coding-char attempts to - ;; remove those extra bytes at least in some situations, but - ;; it cannot do that in all cases. And in any case, producing - ;; what is supposed to be a UTF-16 or ISO-2022-CN encoded - ;; string which lacks the BOM bytes at the beginning and the - ;; charset designation sequences at the head and tail of the - ;; result will definitely surprise the callers in some cases. - (while (let ((encoded (encode-coding-char - (aref string index) coding-system))) - (and (<= (+ (length encoded) result-length) length) - (progn - (push encoded result) - (cl-incf result-length (length encoded)) - (setq index (if end (1- index) - (1+ index)))) - (if end (> index -1) - (< index (length string))))) - ;; No body. - ) - (apply #'concat (if end result (nreverse result)))) + ;; The previous implementation here tried to encode char by + ;; char, and then adding up the length of the encoded octets, + ;; but that's not reliably in the presence of BOM marks and + ;; ISO-2022-CN which may add charset designations at the + ;; start/end of each encoded char (which we don't want). So + ;; iterate (with a binary search) instead to find the desired + ;; length. + (let* ((glyphs (string-glyph-split string)) + (nglyphs (length glyphs)) + (too-long (1+ nglyphs)) + (stop (max (/ nglyphs 2) 1)) + (gap stop) + candidate encoded found candidate-stop) + ;; We're returning the end of the string. + (when end + (setq glyphs (nreverse glyphs))) + (while (and (not found) + (< stop too-long)) + (setq encoded + (encode-coding-string (string-join (seq-take glyphs stop)) + coding-system)) + (cond + ((= (length encoded) length) + (setq found encoded + candidate-stop stop)) + ;; Too long; try shortening. + ((> (length encoded) length) + (setq too-long stop + stop (max (- stop gap) 1))) + ;; Too short; try lengthening. + (t + (setq candidate encoded + candidate-stop stop) + (setq stop + (if (>= stop nglyphs) + too-long + (min (+ stop gap) nglyphs))))) + (setq gap (max (/ gap 2) 1))) + (cond + ((not (or found candidate)) + "") + ;; We're returning the end, so redo the encoding. + (end + (encode-coding-string + (string-join (nreverse (seq-take glyphs candidate-stop))) + coding-system)) + (t + (or found candidate)))) + ;; Char-based version. (cond ((<= (length string) length) string) (end (substring string (- (length string) length))) @@ -224,13 +254,9 @@ the string." (unless (natnump length) (signal 'wrong-type-argument (list 'natnump length))) (let ((pad-length (- length (length string)))) - (if (< pad-length 0) - string - (concat (and start - (make-string pad-length (or padding ?\s))) - string - (and (not start) - (make-string pad-length (or padding ?\s))))))) + (cond ((<= pad-length 0) string) + (start (concat (make-string pad-length (or padding ?\s)) string)) + (t (concat string (make-string pad-length (or padding ?\s))))))) (defun string-chop-newline (string) "Remove the final newline (if any) from STRING." @@ -265,6 +291,7 @@ it makes no sense to convert it to a string using (set-buffer source-buffer) (replace-buffer-contents tmp-buffer max-secs max-costs))))))))) +;;;###autoload (defmacro named-let (name bindings &rest body) "Looping construct taken from Scheme. Like `let', bind variables in BINDINGS and then evaluate BODY, @@ -286,19 +313,6 @@ as the new values of the bound variables in the recursive invocation." (cl-labels ((,name ,fargs . ,body)) #',name) . ,aargs))) -(defmacro with-memoization (place &rest code) - "Return the value of CODE and stash it in PLACE. -If PLACE's value is non-nil, then don't bother evaluating CODE -and return the value found in PLACE instead." - (declare (indent 1) (debug (gv-place body))) - (gv-letplace (getter setter) place - `(or ,getter - ,(macroexp-let2 nil val (macroexp-progn code) - `(progn - ,(funcall setter val) - ,val))))) - - ;;;###autoload (defun string-pixel-width (string) "Return the width of STRING in pixels." @@ -453,6 +467,18 @@ be marked unmodified, effectively ignoring those changes." (equal ,hash (buffer-hash))) (restore-buffer-modified-p nil)))))))) +(defun emacs-etc--hide-local-variables () + "Hide local variables. +Used by `emacs-authors-mode' and `emacs-news-mode'." + (narrow-to-region (point-min) + (save-excursion + (goto-char (point-max)) + ;; Obfuscate to avoid this being interpreted + ;; as a local variable section itself. + (if (re-search-backward "^Local\sVariables:$" nil t) + (progn (forward-line -1) (point)) + (point-max))))) + (provide 'subr-x) ;;; subr-x.el ends here |