diff --git a/lisp/emacs-lisp/lisp-mode.el b/lisp/emacs-lisp/lisp-mode.el index 868a9578..5d912097 100644 --- a/lisp/emacs-lisp/lisp-mode.el +++ b/lisp/emacs-lisp/lisp-mode.el @@ -204,7 +204,7 @@ (pcase-let "defface")) (el-tdefs '("defgroup" "deftheme")) (el-kw '("while-no-input" "letrec" "pcase" "pcase-exhaustive" - "pcase-let" "pcase-let*" "save-restriction" + "pcase-lambda" "pcase-let" "pcase-let*" "save-restriction" "save-excursion" "save-selected-window" ;; "eval-after-load" "eval-next-after-load" "save-window-excursion" "save-current-buffer" diff --git a/lisp/emacs-lisp/macroexp.el b/lisp/emacs-lisp/macroexp.el index 797de9ab..8fe156c4 100644 --- a/lisp/emacs-lisp/macroexp.el +++ b/lisp/emacs-lisp/macroexp.el @@ -297,6 +297,16 @@ (defun macroexpand-all (form &optional environment) ;;; Handy functions to use in macros. +(defun macroexp-parse-body (exps) + "Parse EXPS into (DOC DECLARE-FORM INTERACTIVE-FORM . BODY)." + `(,(and (stringp (car exps)) + (pop exps)) + ,(and (eq (car-safe (car exps)) 'declare) + (pop exps)) + ,(and (eq (car-safe (car exps)) 'interactive) + (pop exps)) + ,@exps)) + (defun macroexp-progn (exps) "Return an expression equivalent to `(progn ,@EXPS)." (if (cdr exps) `(progn ,@exps) (car exps))) diff --git a/lisp/emacs-lisp/pcase.el b/lisp/emacs-lisp/pcase.el index b495793b..0c71451b 100644 --- a/lisp/emacs-lisp/pcase.el +++ b/lisp/emacs-lisp/pcase.el @@ -164,6 +164,23 @@ (defmacro pcase-exhaustive (exp &rest cases) ;; FIXME: Could we add the FILE:LINE data in the error message? exp (append cases `((,x (error "No clause matching `%S'" ,x))))))) +;;;###autoload +(defmacro pcase-lambda (lambda-list &rest body) + (declare (doc-string 2) (indent defun)) + (let ((args (make-symbol "args")) + (pats (mapcar (lambda (u) + (unless (eq u '&rest) + (if (eq (car-safe u) '\`) (cadr u) (list '\, u)))) + lambda-list)) + (body (macroexp-parse-body body))) + ;; Handle &rest + (when (eq nil (car (last pats 2))) + (setq pats (append (butlast pats 2) (car (last pats))))) + `(lambda (&rest ,args) + ,@(remq nil (list (nth 0 body) (nth 1 body) (nth 2 body))) + (pcase ,args + (,(list '\` pats) . ,(nthcdr 3 body)))))) + (defun pcase--let* (bindings body) (cond ((null bindings) (macroexp-progn body))