diff options
Diffstat (limited to 'lisp/emacs-lisp/pcase.el')
| -rw-r--r-- | lisp/emacs-lisp/pcase.el | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/lisp/emacs-lisp/pcase.el b/lisp/emacs-lisp/pcase.el index e9b2980d3ed..898d460c144 100644 --- a/lisp/emacs-lisp/pcase.el +++ b/lisp/emacs-lisp/pcase.el @@ -181,6 +181,7 @@ Emacs Lisp manual for more information and examples." (let* ((main (documentation (symbol-function 'pcase) 'raw)) (ud (help-split-fundoc main 'pcase))) (require 'help-fns) + (declare-function help-fns-short-filename "help-fns" (filename)) (declare-function help-fns--signature "help-fns" (function doc real-def real-function buffer)) (with-temp-buffer @@ -213,9 +214,7 @@ Emacs Lisp manual for more information and examples." (save-excursion (forward-char -1) (insert (format-message " in `")) - ;; `file-name-nondirectory' is naive, but - ;; `help-fns-short-filename' is not fast enough yet (bug#73766). - (help-insert-xref-button (file-name-nondirectory filename) + (help-insert-xref-button (help-fns-short-filename filename) 'help-function-def symbol filename 'pcase-macro) (insert (format-message "'.")))) @@ -242,9 +241,14 @@ not signal an error." ;;;###autoload (defmacro pcase-lambda (lambda-list &rest body) "Like `lambda' but allow each argument to be a pattern. -I.e. accepts the usual &optional and &rest keywords, but every -formal argument can be any pattern accepted by `pcase' (a mere -variable name being but a special case of it)." +I.e. accepts the usual &optional and &rest keywords, but every formal +argument can be any pattern destructed by `pcase-let' (a mere variable +name being but a special case of it). + +Each argument should match its respective pattern in the parameter +list (i.e. be of a compatible structure); a mismatch may signal an error +or may go undetected, binding arguments to arbitrary values, such as +nil." (declare (doc-string 2) (indent defun) (debug (&define (&rest pcase-PAT) lambda-doc def-body))) (let* ((bindings ()) @@ -1170,7 +1174,11 @@ The predicate is the logical-AND of: `'(,(cadr upata) . ,(cadr upatd)) `(and (pred consp) (app car-safe ,upata) - (app cdr-safe ,upatd))))) + (app cdr-safe ,upatd) + ,@(when (eq (car qpat) '\`) + `((guard ,(macroexp-warn-and-return + "Nested ` are not supported in Pcase patterns" + t nil nil qpat)))))))) ((or (stringp qpat) (numberp qpat) (symbolp qpat)) `',qpat) ;; In all other cases just raise an error so we can't break ;; backward compatibility when adding \` support for other |