diff options
Diffstat (limited to 'lisp/emacs-lisp/subr-x.el')
| -rw-r--r-- | lisp/emacs-lisp/subr-x.el | 55 |
1 files changed, 23 insertions, 32 deletions
diff --git a/lisp/emacs-lisp/subr-x.el b/lisp/emacs-lisp/subr-x.el index 21dba377bf1..b2d7f0dec4f 100644 --- a/lisp/emacs-lisp/subr-x.el +++ b/lisp/emacs-lisp/subr-x.el @@ -121,7 +121,7 @@ If ELT is of the form ((EXPR)), listify (EXPR) with a dummy symbol." binding)) bindings))) -(defmacro if-let* (varlist then &rest else) +(defmacro if-let (varlist then &rest else) "Bind variables according to VARLIST and eval THEN or ELSE. Each binding is evaluated in turn, and evaluation stops if a binding value is nil. If all are non-nil, the value of THEN is @@ -131,10 +131,18 @@ Each element of VARLIST is a list (SYMBOL VALUEFORM) which binds SYMBOL to the value of VALUEFORM. An element can additionally be of the form (VALUEFORM), which is evaluated and checked for nil; i.e. SYMBOL can be omitted if only the test result is of -interest." +interest. + +As a special case, a VARLIST of the form (SYMBOL SOMETHING) is +treated like ((SYMBOL SOMETHING))." (declare (indent 2) - (debug ((&rest [&or symbolp (symbolp form) (form)]) + (debug ([&or (symbolp form) + (&rest [&or symbolp (symbolp form) (form)])] form body))) + (pcase varlist + (`(,(pred symbolp) ,_) + ;; the single-tuple syntax case, for backward compatibility + (cl-callf list varlist))) (if varlist `(let* ,(setq varlist (internal--build-bindings varlist)) (if ,(caar (last varlist)) @@ -142,23 +150,23 @@ interest." ,@else)) `(let* () ,then))) -(defmacro when-let* (varlist &rest body) +(defmacro when-let (varlist &rest body) "Bind variables according to VARLIST and conditionally eval BODY. Each binding is evaluated in turn, and evaluation stops if a binding value is nil. If all are non-nil, the value of the last form in BODY is returned. -VARLIST is the same as in `if-let*'." - (declare (indent 1) (debug if-let*)) - (list 'if-let* varlist (macroexp-progn body))) +VARLIST is the same as in `if-let'." + (declare (indent 1) (debug ([&or (symbolp form) + (&rest [&or symbolp (symbolp form) (form)])] + body))) + (list 'if-let varlist (macroexp-progn body))) -(defmacro and-let* (varlist &rest body) +(defmacro and-let (varlist &rest body) "Bind variables according to VARLIST and conditionally eval BODY. -Like `when-let*', except if BODY is empty and all the bindings +Like `when-let', except if BODY is empty and all the bindings are non-nil, then the result is non-nil." - (declare (indent 1) - (debug ((&rest [&or symbolp (symbolp form) (form)]) - body))) + (declare (indent 1) (debug when-let)) (let (res) (if varlist `(let* ,(setq varlist (internal--build-bindings varlist)) @@ -166,26 +174,9 @@ are non-nil, then the result is non-nil." ,@(or body `(,res)))) `(let* () ,@(or body '(t)))))) -(defmacro if-let (spec then &rest else) - "Bind variables according to SPEC and eval THEN or ELSE. -Like `if-let*' except SPEC can have the form (SYMBOL VALUEFORM)." - (declare (indent 2) - (debug ([&or (&rest [&or symbolp (symbolp form) (form)]) - (symbolp form)] - form body)) - (obsolete "use `if-let*' instead." "26.1")) - (when (and (<= (length spec) 2) - (not (listp (car spec)))) - ;; Adjust the single binding case - (setq spec (list spec))) - (list 'if-let* spec then (macroexp-progn else))) - -(defmacro when-let (spec &rest body) - "Bind variables according to SPEC and conditionally eval BODY. -Like `when-let*' except SPEC can have the form (SYMBOL VALUEFORM)." - (declare (indent 1) (debug if-let) - (obsolete "use `when-let*' instead." "26.1")) - (list 'if-let spec (macroexp-progn body))) +(defalias 'if-let* #'if-let) +(defalias 'when-let* #'when-let) +(defalias 'and-let* #'and-let) (defsubst hash-table-empty-p (hash-table) "Check whether HASH-TABLE is empty (has 0 elements)." |