alexandria-devel November 2009

alexandria-devel@common-lisp.net

3 participants
5 discussions

[alexandria-devel] Review cycle 2: SWITCH, ESCWITCH, and CSWITCH
by Nikodemus Siivola 08 Apr '10

08 Apr '10

macro switch ((object &key test key) &body clauses) "Evaluates first matching clause, returning its values, or evaluates and returns the values of DEFAULT if no keys match." macro eswitch ((object &key test key) &body clauses) "Like SWITCH, but signals an error if no key matches." cswitch ((object &key test key) &body clauses) "Like SWITCH, but signals a continuable error if no key matches."

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[alexandria-devel] Lost earmuff in tests.lisp
by Peter Graves 11 Mar '10

11 Mar '10

diff -rN -u old-alexandria/tests.lisp new-alexandria/tests.lisp --- old-alexandria/tests.lisp 2009-10-07 03:51:00.000000000 -0700 +++ new-alexandria/tests.lisp 2009-10-07 03:51:01.000000000 -0700 @@ -7,7 +7,7 @@ (in-package :alexandria-tests) -(defun run-tests (&key ((:compiled *compile-tests))) +(defun run-tests (&key ((:compiled *compile-tests*))) (do-tests)) ;;;; Arrays

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[alexandria-devel] eval-always, defun-always, etc...
by Attila Lendvai 03 Dec '09

03 Dec '09

dear list, i know that this is a subject that has strong feelings attached to, but with recent developments in XCVB the need for (eval-when (:compile-toplevel :load-toplevel :execute) ...) has rose, and seeing numerous eval-when noise in the code is potentially annoying. related material: a) relevant part of XCVB docs: http://common-lisp.net/project/xcvb/doc/README.html#compile-time-side-effec… b) "XCVB patch for Alexandria" thread on alexandria-devel c) blog entry from Nikodemus at http://random-state.net/log/3387124996.html (broken currently, google cache below) http://209.85.129.132/search?q=cache:dmgWWKN8vFMJ:random-state.net/log/3387… ============= c) makes it clear that Nikodemus doesn't like eval-always, and i'm sure many other lispers are on the same opinion. for the argument that it does not introduce a new abstraction, i can point to COND, which is the same as an ugly IF ladder, still most people prefer COND when there are many legs of that if, because in that case COND is much less noisy. no new abstraction, only a syntactic sugar, but it's much easier for the eye. a) has a detailed description why often a full (:compile-toplevel :load-toplevel :execute) is necessary, and it'll be even more so as XCVB gets used more and more. so, i'd suggest to take some action: I) add an eval-always to alexandria-devel II) add a defun-always to alexandria-devel avoid the entire need for a wrapper III) ? my vote goes for II), which is kinda in sync with c) too. suggestions? opinions? -- attila

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[alexandria-devel] cdr assoc (now called alist-get)
by John Fremlin 25 Nov '09

25 Nov '09

For http://common-lisp.net/project/cl-irregsexp/ and in fact for many other projects, it is quite handy to have a way of storing key value pairs in a table that is more lightweight than a hashtable, and that preserves ordering. The obvious way to do it in Lisp is to store a list like '((key0 . value0) (key1 . value1) ...) However in the ANSI standard there is no easy way to implement (setf (gethash key table) value). (cdr (assoc ...)) is sufficient for lookup. To that end there is commonly available in extensions a (setf cdr-assoc). I posted one to the list before but I had managed to mangle it utterly in my last edit of it and it didn't work. I hope that was why you Alexandrians ignored me . . . Anyway, one problem with cdr-assoc is that the order of parameters is apparently non-standard. To alleviate this problem I have come back with a new name, alist-get and also ralist-get (for cdr-rassoc, the (value.key) convention). Feedback very much appreciated! (declaim (inline racons)) (defun racons (key value ralist) (acons value key ralist)) (macrolet ((define-alist-get (name get-pair get-value-from-pair add) `(progn (declaim (inline ,name)) (defun ,name (alist key &key (test 'eql)) (let ((pair (,get-pair key alist :test test))) (values (,get-value-from-pair pair) pair))) (define-setf-expander ,name (place key &key (test ''eql) &environment env) (multiple-value-bind (dummies vals newvals setter getter) (get-setf-expansion place env) (when (cdr newvals) (error "~A cannot store multiple values in one place" ',name)) (with-unique-names (store key-val test-val alist found) (values `(,@dummies ,key-val ,test-val) `(,@vals ,key ,test) (list store) `(let ((,alist ,getter)) (let ((,found (,',get-pair ,key-val ,alist :test ,test-val))) (cond (,found (setf (,',get-value-from-pair ,found) ,store)) (t (let ,newvals (setf ,(first newvals) (,',add ,key ,store ,alist)) ,setter))) ,store)) `(,',name ,getter ,key)))))))) (define-alist-get alist-get assoc cdr acons) (define-alist-get ralist-get rassoc car racons))

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[alexandria-devel] conjoin bug fix
by Kilian Sprotte 02 Nov '09

02 Nov '09

Hi, I stumbled (probably due to some macro-expansion) over the following degenerate case of conjoin: (funcall (conjoin #'zerop) 0) It fails with NIL is not a function. I propose the changes below (also attached as a darcs patch). Cheers, Kilian Thu Oct 15 16:42:45 CEST 2009 Kilian Sprotte <kilian.sprotte(a)gmail.com> * conjoin bug fix for single predicate argument diff -rN old-alexandria/functions.lisp new-alexandria/functions.lisp 40,49c40,51 < (lambda (&rest arguments) < (and (apply predicate arguments) < ;; Cannot simply use CL:EVERY because we want to return the < ;; non-NIL value of the last predicate if all succeed. < (do ((tail (cdr more-predicates) (cdr tail)) < (head (car more-predicates) (car tail))) < ((not tail) < (apply head arguments)) < (unless (apply head arguments) < (return nil)))))) --- > (if (null more-predicates) > predicate > (lambda (&rest arguments) > (and (apply predicate arguments) > ;; Cannot simply use CL:EVERY because we want to return the > ;; non-NIL value of the last predicate if all succeed. > (do ((tail (cdr more-predicates) (cdr tail)) > (head (car more-predicates) (car tail))) > ((not tail) > (apply head arguments)) > (unless (apply head arguments) > (return nil))))))) diff -rN old-alexandria/tests.lisp new-alexandria/tests.lisp 359a360,365 > (deftest conjoin.2 > (let ((conjunction (conjoin #'zerop))) > (list (funcall conjunction 0) > (funcall conjunction 1))) > (t nil)) > -- Kilian Sprotte 10405 Berlin

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alexandria-devel November 2009