>From 69d1375dd100f46100c0bbf2cff42846a8cdd139 Mon Sep 17 00:00:00 2001 From: Michael Heerdegen Date: Wed, 21 Feb 2018 11:15:37 +0100 Subject: [PATCH] Define if-let* and derivatives as aliases of if-let This commit reverts declaring `if-let' and `when-let' obsolete in favor of the new `if-let* and `when-let*' versions because of the compiler warning mess (Bug#30039). Instead we make foo-let and foo-let* aliases. The old single-tuple variable spec case is still supported for backward compatibility. * lisp/emacs-lisp/subr-x.el (if-let, when-let): Don't declare obsolete. Tweak edebug specs. (and-let): Renamed from `and-let*' for compatibility with the names `if-let' and `when-let'. (if-let*, when-let*, and-let*): Define as aliases of `if-let', `when-let' and `and-let'. * test/lisp/emacs-lisp/subr-x-tests.el (if-let-single-tuple-case-test) (when-let-single-tuple-case-test): New tests for the single-binding tuple case. In the whole file, prefer the names without "*". --- etc/NEWS | 10 +- lisp/emacs-lisp/subr-x.el | 55 ++++----- test/lisp/emacs-lisp/subr-x-tests.el | 232 ++++++++++++++++++----------------- 3 files changed, 148 insertions(+), 149 deletions(-) diff --git a/etc/NEWS b/etc/NEWS index eded00e655..c88bec5a56 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -1301,12 +1301,10 @@ current buffer or the self-insertion takes place within a comment. ** The alist 'ucs-names' is now a hash table. --- -** 'if-let' and 'when-let' are subsumed by 'if-let*' and 'when-let*'. -The incumbent 'if-let' and 'when-let' are now marked obsolete. -'if-let*' and 'when-let*' do not accept the single tuple special case. -New macro 'and-let*' is an implementation of the Scheme SRFI-2 syntax -of the same name. 'if-let*' and 'when-let*' now accept the same -binding syntax as 'and-let*'. +** The new macro 'and-let' is an implementation of the Scheme SRFI-2 +syntax. 'if-let' and 'when-let' now also accept the same binding +syntax as 'and-let'. 'if-let*', 'when-let*' and 'and-let*' are new +aliases for 'if-let', 'when-let' and 'and-let'. --- ** 'C-up', 'C-down', 'C-left' and 'C-right' are now defined in term diff --git a/lisp/emacs-lisp/subr-x.el b/lisp/emacs-lisp/subr-x.el index 21dba377bf..b2d7f0dec4 100644 --- a/lisp/emacs-lisp/subr-x.el +++ b/lisp/emacs-lisp/subr-x.el @@ -121,7 +121,7 @@ internal--build-bindings 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 @@ if-let* 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 @@ if-let* ,@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 @@ and-let* ,@(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)." diff --git a/test/lisp/emacs-lisp/subr-x-tests.el b/test/lisp/emacs-lisp/subr-x-tests.el index c9618f3c37..a361718c9e 100644 --- a/test/lisp/emacs-lisp/subr-x-tests.el +++ b/test/lisp/emacs-lisp/subr-x-tests.el @@ -28,13 +28,13 @@ (require 'subr-x) -;; `if-let*' tests +;; `if-let' tests -(ert-deftest subr-x-test-if-let*-single-binding-expansion () +(ert-deftest subr-x-test-if-let-single-binding-expansion () "Test single bindings are expanded properly." (should (equal (macroexpand - '(if-let* ((a 1)) + '(if-let ((a 1)) (- a) "no")) '(let* ((a (and t 1))) @@ -43,7 +43,7 @@ "no")))) (should (equal (macroexpand - '(if-let* (a) + '(if-let (a) (- a) "no")) '(let* ((a (and t a))) @@ -51,11 +51,11 @@ (- a) "no"))))) -(ert-deftest subr-x-test-if-let*-single-symbol-expansion () +(ert-deftest subr-x-test-if-let-single-symbol-expansion () "Test single symbol bindings are expanded properly." (should (equal (macroexpand - '(if-let* (a) + '(if-let (a) (- a) "no")) '(let* ((a (and t a))) @@ -64,7 +64,7 @@ "no")))) (should (equal (macroexpand - '(if-let* (a b c) + '(if-let (a b c) (- a) "no")) '(let* ((a (and t a)) @@ -75,7 +75,7 @@ "no")))) (should (equal (macroexpand - '(if-let* (a (b 2) c) + '(if-let (a (b 2) c) (- a) "no")) '(let* ((a (and t a)) @@ -85,11 +85,11 @@ (- a) "no"))))) -(ert-deftest subr-x-test-if-let*-nil-related-expansion () +(ert-deftest subr-x-test-if-let-nil-related-expansion () "Test nil is processed properly." (should (equal (macroexpand - '(if-let* (nil) + '(if-let (nil) (- a) "no")) '(let* ((nil (and t nil))) @@ -98,7 +98,7 @@ "no")))) (should (equal (macroexpand - '(if-let* ((a 1) nil (b 2)) + '(if-let ((a 1) nil (b 2)) (- a) "no")) '(let* ((a (and t 1)) @@ -108,106 +108,106 @@ (- a) "no"))))) -(ert-deftest subr-x-test-if-let*-malformed-binding () +(ert-deftest subr-x-test-if-let-malformed-binding () "Test malformed bindings trigger errors." (should-error (macroexpand - '(if-let* (_ (a 1 1) (b 2) (c 3) d) + '(if-let (_ (a 1 1) (b 2) (c 3) d) (- a) "no")) :type 'error) (should-error (macroexpand - '(if-let* (_ (a 1) (b 2 2) (c 3) d) + '(if-let (_ (a 1) (b 2 2) (c 3) d) (- a) "no")) :type 'error) (should-error (macroexpand - '(if-let* (_ (a 1) (b 2) (c 3 3) d) + '(if-let (_ (a 1) (b 2) (c 3 3) d) (- a) "no")) :type 'error) (should-error (macroexpand - '(if-let* ((a 1 1)) + '(if-let ((a 1 1)) (- a) "no")) :type 'error)) -(ert-deftest subr-x-test-if-let*-true () +(ert-deftest subr-x-test-if-let-true () "Test `if-let' with truthy bindings." (should (equal - (if-let* ((a 1)) + (if-let ((a 1)) a "no") 1)) (should (equal - (if-let* ((a 1) (b 2) (c 3)) + (if-let ((a 1) (b 2) (c 3)) (list a b c) "no") (list 1 2 3)))) -(ert-deftest subr-x-test-if-let*-false () +(ert-deftest subr-x-test-if-let-false () "Test `if-let' with falsie bindings." (should (equal - (if-let* ((a nil)) + (if-let ((a nil)) (list a b c) "no") "no")) (should (equal - (if-let* ((a nil) (b 2) (c 3)) + (if-let ((a nil) (b 2) (c 3)) (list a b c) "no") "no")) (should (equal - (if-let* ((a 1) (b nil) (c 3)) + (if-let ((a 1) (b nil) (c 3)) (list a b c) "no") "no")) (should (equal - (if-let* ((a 1) (b 2) (c nil)) + (if-let ((a 1) (b 2) (c nil)) (list a b c) "no") "no")) (should (equal (let (z) - (if-let* (z (a 1) (b 2) (c 3)) + (if-let (z (a 1) (b 2) (c 3)) (list a b c) "no")) "no")) (should (equal (let (d) - (if-let* ((a 1) (b 2) (c 3) d) + (if-let ((a 1) (b 2) (c 3) d) (list a b c) "no")) "no"))) -(ert-deftest subr-x-test-if-let*-bound-references () +(ert-deftest subr-x-test-if-let-bound-references () "Test `if-let' bindings can refer to already bound symbols." (should (equal - (if-let* ((a (1+ 0)) (b (1+ a)) (c (1+ b))) + (if-let ((a (1+ 0)) (b (1+ a)) (c (1+ b))) (list a b c) "no") (list 1 2 3)))) -(ert-deftest subr-x-test-if-let*-and-laziness-is-preserved () +(ert-deftest subr-x-test-if-let-and-laziness-is-preserved () "Test `if-let' respects `and' laziness." (let (a-called b-called c-called) (should (equal - (if-let* ((a nil) - (b (setq b-called t)) - (c (setq c-called t))) + (if-let ((a nil) + (b (setq b-called t)) + (c (setq c-called t))) "yes" (list a-called b-called c-called)) (list nil nil nil)))) (let (a-called b-called c-called) (should (equal - (if-let* ((a (setq a-called t)) - (b nil) - (c (setq c-called t))) + (if-let ((a (setq a-called t)) + (b nil) + (c (setq c-called t))) "yes" (list a-called b-called c-called)) (list t nil nil)))) (let (a-called b-called c-called) (should (equal - (if-let* ((a (setq a-called t)) + (if-let ((a (setq a-called t)) (b (setq b-called t)) (c nil) (d (setq c-called t))) @@ -215,14 +215,19 @@ (list a-called b-called c-called)) (list t t nil))))) +(defun if-let-single-tuple-case-test () + "Test the BINDING-SPEC == (SYMBOL SOMETHING) case." + (should (equal (if-let (a 1) (1+ a)) 2)) + (should (equal (let ((b 2)) (if-let (a b) a)) 2))) + -;; `when-let*' tests +;; `when-let' tests -(ert-deftest subr-x-test-when-let*-body-expansion () +(ert-deftest subr-x-test-when-let-body-expansion () "Test body allows for multiple sexps wrapping with progn." (should (equal (macroexpand - '(when-let* ((a 1)) + '(when-let ((a 1)) (message "opposite") (- a))) '(let* ((a (and t 1))) @@ -231,18 +236,18 @@ (message "opposite") (- a))))))) -(ert-deftest subr-x-test-when-let*-single-symbol-expansion () +(ert-deftest subr-x-test-when-let-single-symbol-expansion () "Test single symbol bindings are expanded properly." (should (equal (macroexpand - '(when-let* (a) + '(when-let (a) (- a))) '(let* ((a (and t a))) (if a (- a))))) (should (equal (macroexpand - '(when-let* (a b c) + '(when-let (a b c) (- a))) '(let* ((a (and t a)) (b (and a b)) @@ -251,7 +256,7 @@ (- a))))) (should (equal (macroexpand - '(when-let* (a (b 2) c) + '(when-let (a (b 2) c) (- a))) '(let* ((a (and t a)) (b (and a 2)) @@ -259,18 +264,18 @@ (if c (- a)))))) -(ert-deftest subr-x-test-when-let*-nil-related-expansion () +(ert-deftest subr-x-test-when-let-nil-related-expansion () "Test nil is processed properly." (should (equal (macroexpand - '(when-let* (nil) + '(when-let (nil) (- a))) '(let* ((nil (and t nil))) (if nil (- a))))) (should (equal (macroexpand - '(when-let* ((a 1) nil (b 2)) + '(when-let ((a 1) nil (b 2)) (- a))) '(let* ((a (and t 1)) (nil (and a nil)) @@ -278,173 +283,178 @@ (if b (- a)))))) -(ert-deftest subr-x-test-when-let*-malformed-binding () +(ert-deftest subr-x-test-when-let-malformed-binding () "Test malformed bindings trigger errors." (should-error (macroexpand - '(when-let* (_ (a 1 1) (b 2) (c 3) d) + '(when-let (_ (a 1 1) (b 2) (c 3) d) (- a))) :type 'error) (should-error (macroexpand - '(when-let* (_ (a 1) (b 2 2) (c 3) d) + '(when-let (_ (a 1) (b 2 2) (c 3) d) (- a))) :type 'error) (should-error (macroexpand - '(when-let* (_ (a 1) (b 2) (c 3 3) d) + '(when-let (_ (a 1) (b 2) (c 3 3) d) (- a))) :type 'error) (should-error (macroexpand - '(when-let* ((a 1 1)) + '(when-let ((a 1 1)) (- a))) :type 'error)) -(ert-deftest subr-x-test-when-let*-true () +(ert-deftest subr-x-test-when-let-true () "Test `when-let' with truthy bindings." (should (equal - (when-let* ((a 1)) + (when-let ((a 1)) a) 1)) (should (equal - (when-let* ((a 1) (b 2) (c 3)) + (when-let ((a 1) (b 2) (c 3)) (list a b c)) (list 1 2 3)))) -(ert-deftest subr-x-test-when-let*-false () +(ert-deftest subr-x-test-when-let-false () "Test `when-let' with falsie bindings." (should (equal - (when-let* ((a nil)) + (when-let ((a nil)) (list a b c) "no") nil)) (should (equal - (when-let* ((a nil) (b 2) (c 3)) + (when-let ((a nil) (b 2) (c 3)) (list a b c) "no") nil)) (should (equal - (when-let* ((a 1) (b nil) (c 3)) + (when-let ((a 1) (b nil) (c 3)) (list a b c) "no") nil)) (should (equal - (when-let* ((a 1) (b 2) (c nil)) + (when-let ((a 1) (b 2) (c nil)) (list a b c) "no") nil)) (should (equal (let (z) - (when-let* (z (a 1) (b 2) (c 3)) + (when-let (z (a 1) (b 2) (c 3)) (list a b c) "no")) nil)) (should (equal (let (d) - (when-let* ((a 1) (b 2) (c 3) d) + (when-let ((a 1) (b 2) (c 3) d) (list a b c) "no")) nil))) -(ert-deftest subr-x-test-when-let*-bound-references () +(ert-deftest subr-x-test-when-let-bound-references () "Test `when-let' bindings can refer to already bound symbols." (should (equal - (when-let* ((a (1+ 0)) (b (1+ a)) (c (1+ b))) + (when-let ((a (1+ 0)) (b (1+ a)) (c (1+ b))) (list a b c)) (list 1 2 3)))) -(ert-deftest subr-x-test-when-let*-and-laziness-is-preserved () +(ert-deftest subr-x-test-when-let-and-laziness-is-preserved () "Test `when-let' respects `and' laziness." (let (a-called b-called c-called) (should (equal (progn - (when-let* ((a nil) - (b (setq b-called t)) - (c (setq c-called t))) + (when-let ((a nil) + (b (setq b-called t)) + (c (setq c-called t))) "yes") (list a-called b-called c-called)) (list nil nil nil)))) (let (a-called b-called c-called) (should (equal (progn - (when-let* ((a (setq a-called t)) - (b nil) - (c (setq c-called t))) + (when-let ((a (setq a-called t)) + (b nil) + (c (setq c-called t))) "yes") (list a-called b-called c-called)) (list t nil nil)))) (let (a-called b-called c-called) (should (equal (progn - (when-let* ((a (setq a-called t)) - (b (setq b-called t)) - (c nil) - (d (setq c-called t))) + (when-let ((a (setq a-called t)) + (b (setq b-called t)) + (c nil) + (d (setq c-called t))) "yes") (list a-called b-called c-called)) (list t t nil))))) +(defun when-let-single-tuple-case-test () + "Test the BINDING-SPEC == (SYMBOL SOMETHING) case." + (should (equal (when-let (a 1) (1+ a)) 2)) + (should (equal (let ((b 2)) (when-let (a b) a)) 2))) + -;; `and-let*' tests +;; `and-let' tests ;; Adapted from the Guile tests ;; https://git.savannah.gnu.org/cgit/guile.git/tree/test-suite/tests/srfi-2.test -(ert-deftest subr-x-and-let*-test-empty-varlist () - (should (equal 1 (and-let* () 1))) - (should (equal 2 (and-let* () 1 2))) - (should (equal t (and-let* ())))) +(ert-deftest subr-x-and-let-test-empty-varlist () + (should (equal 1 (and-let () 1))) + (should (equal 2 (and-let () 1 2))) + (should (equal t (and-let ())))) -(ert-deftest subr-x-and-let*-test-group-1 () - (should (equal nil (let ((x nil)) (and-let* (x))))) - (should (equal 1 (let ((x 1)) (and-let* (x))))) - (should (equal nil (and-let* ((x nil))))) - (should (equal 1 (and-let* ((x 1))))) +(ert-deftest subr-x-and-let-test-group-1 () + (should (equal nil (let ((x nil)) (and-let (x))))) + (should (equal 1 (let ((x 1)) (and-let (x))))) + (should (equal nil (and-let ((x nil))))) + (should (equal 1 (and-let ((x 1))))) ;; The error doesn't trigger when compiled: the compiler will give ;; a warning and then drop the erroneous code. Therefore, use ;; `eval' to avoid compilation. - (should-error (eval '(and-let* (nil (x 1))) lexical-binding) + (should-error (eval '(and-let (nil (x 1))) lexical-binding) :type 'setting-constant) - (should (equal nil (and-let* ((nil) (x 1))))) - (should-error (eval '(and-let* (2 (x 1))) lexical-binding) + (should (equal nil (and-let ((nil) (x 1))))) + (should-error (eval '(and-let (2 (x 1))) lexical-binding) :type 'wrong-type-argument) - (should (equal 1 (and-let* ((2) (x 1))))) - (should (equal 2 (and-let* ((x 1) (2))))) - (should (equal nil (let ((x nil)) (and-let* (x) x)))) - (should (equal "" (let ((x "")) (and-let* (x) x)))) - (should (equal "" (let ((x "")) (and-let* (x))))) - (should (equal 2 (let ((x 1)) (and-let* (x) (+ x 1))))) - (should (equal nil (let ((x nil)) (and-let* (x) (+ x 1))))) - (should (equal 2 (let ((x 1)) (and-let* (((> x 0))) (+ x 1))))) - (should (equal t (let ((x 1)) (and-let* (((> x 0))))))) - (should (equal nil (let ((x 0)) (and-let* (((> x 0))) (+ x 1))))) + (should (equal 1 (and-let ((2) (x 1))))) + (should (equal 2 (and-let ((x 1) (2))))) + (should (equal nil (let ((x nil)) (and-let (x) x)))) + (should (equal "" (let ((x "")) (and-let (x) x)))) + (should (equal "" (let ((x "")) (and-let (x))))) + (should (equal 2 (let ((x 1)) (and-let (x) (+ x 1))))) + (should (equal nil (let ((x nil)) (and-let (x) (+ x 1))))) + (should (equal 2 (let ((x 1)) (and-let (((> x 0))) (+ x 1))))) + (should (equal t (let ((x 1)) (and-let (((> x 0))))))) + (should (equal nil (let ((x 0)) (and-let (((> x 0))) (+ x 1))))) (should (equal 3 - (let ((x 1)) (and-let* (((> x 0)) (x (+ x 1))) (+ x 1)))))) + (let ((x 1)) (and-let (((> x 0)) (x (+ x 1))) (+ x 1)))))) -(ert-deftest subr-x-and-let*-test-rebind () +(ert-deftest subr-x-and-let-test-rebind () (should (equal 4 (let ((x 1)) - (and-let* (((> x 0)) (x (+ x 1)) (x (+ x 1))) (+ x 1)))))) + (and-let (((> x 0)) (x (+ x 1)) (x (+ x 1))) (+ x 1)))))) -(ert-deftest subr-x-and-let*-test-group-2 () +(ert-deftest subr-x-and-let-test-group-2 () (should - (equal 2 (let ((x 1)) (and-let* (x ((> x 0))) (+ x 1))))) + (equal 2 (let ((x 1)) (and-let (x ((> x 0))) (+ x 1))))) (should - (equal 2 (let ((x 1)) (and-let* (((progn x)) ((> x 0))) (+ x 1))))) - (should (equal nil (let ((x 0)) (and-let* (x ((> x 0))) (+ x 1))))) - (should (equal nil (let ((x nil)) (and-let* (x ((> x 0))) (+ x 1))))) + (equal 2 (let ((x 1)) (and-let (((progn x)) ((> x 0))) (+ x 1))))) + (should (equal nil (let ((x 0)) (and-let (x ((> x 0))) (+ x 1))))) + (should (equal nil (let ((x nil)) (and-let (x ((> x 0))) (+ x 1))))) (should - (equal nil (let ((x nil)) (and-let* (((progn x)) ((> x 0))) (+ x 1)))))) + (equal nil (let ((x nil)) (and-let (((progn x)) ((> x 0))) (+ x 1)))))) -(ert-deftest subr-x-and-let*-test-group-3 () +(ert-deftest subr-x-and-let-test-group-3 () (should - (equal nil (let ((x 1)) (and-let* (x (y (- x 1)) ((> y 0))) (/ x y))))) + (equal nil (let ((x 1)) (and-let (x (y (- x 1)) ((> y 0))) (/ x y))))) (should - (equal nil (let ((x 0)) (and-let* (x (y (- x 1)) ((> y 0))) (/ x y))))) + (equal nil (let ((x 0)) (and-let (x (y (- x 1)) ((> y 0))) (/ x y))))) (should (equal nil - (let ((x nil)) (and-let* (x (y (- x 1)) ((> y 0))) (/ x y))))) + (let ((x nil)) (and-let (x (y (- x 1)) ((> y 0))) (/ x y))))) (should (equal (/ 3.0 2) - (let ((x 3.0)) (and-let* (x (y (- x 1)) ((> y 0))) (/ x y)))))) + (let ((x 3.0)) (and-let (x (y (- x 1)) ((> y 0))) (/ x y)))))) -- 2.16.1