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[alexandria-devel] request for using your code in alexandria
by Attila Lendvai 03 Jun '08

03 Jun '08

hi Marco, we would like to copy and/or modify some of your work you have done in Arnesi and add it to Alexandria. if you approve it, could you please answer publicly to the list? thanks in advance, - alexandria developer team

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[alexandria-devel] Review cycle 1: binding constructs
by Nikodemus Siivola 02 Jun '08

02 Jun '08

macro IF-LET (bindings then-form &optional else-form) Creates new variable bindings, and conditionally executes either THEN-FORM or ELSE-FORM. ELSE-FORM defaults to NIL. BINDINGS must be either single binding of the form: (variable initial-form) or a list of bindings of the form: ((variable-1 initial-form-1) (variable-2 initial-form-2) ... (variable-n initial-form-n)) All initial-forms are executed sequentially in the specified order. Then all the variables are bound to the corresponding values. If all variables were bound to true values, the THEN-FORM is executed with the bindings in effect, otherwise the ELSE-FORM is executed with the bindings in effect. ------- macro IF-LET* (bindings then-form &optional else-form) Creates new variable bindings, and conditionally executes either THEN-FORM or ELSE-FORM. ELSE-FORM defaults to NIL. BINDINGS must be either single binding of the form: (variable initial-form) or a list of bindings of the form: ((variable-1 initial-form-1) (variable-2 initial-form-2) ... (variable-n initial-form-n)) Each initial-form is executed in turn, and the variable bound to the corresponding value. Initial-form expressions can refer to variables previously bound by the IF-LET*. If all variables are true after the bindings are complete, the THEN-FORM is executed with the bindings in effect, otherwise the ELSE-FORM is executed with the bindings in effect. ------ macro WHEN-LET (bindings &body forms) Creates new variable bindings, and conditionally executes FORMS. BINDINGS must be either single binding of the form: (variable initial-form) or a list of bindings of the form: ((variable-1 initial-form-1) (variable-2 initial-form-2) ... (variable-n initial-form-n)) All initial-forms are executed sequentially in the specified order. Then all the variables are bound to the corresponding values. If all variables were bound to true values, then FORMS are executed as an implicit PROGN. ------ WHEN-LET* (bindings &body forms) Creates new variable bindings, and conditionally executes FORMS. BINDINGS must be either single binding of the form: (variable initial-form) or a list of bindings of the form: ((variable-1 initial-form-1) (variable-2 initial-form-2) ... (variable-n initial-form-n)) Each initial-form is executed in turn, and the variable bound to the corresponding value. Initial-form expressions can refer to variables previously bound by the WHEN-LET*. If all variables are true after the bindings are complete, then FORMS are executed as an implicit PROGN. ------ The floor is open, -- Nikodemus

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[alexandria-devel] Let's start the review/veto cycle
by Nikodemus Siivola 27 May '08

27 May '08

Consider the interfaces up to Sun Apr 27 23:53:01 EEST 2008 attila.lendvai(a)gmail.com * added simple-parse-error under review. I think we can still continue adding new stuff, but once the cycle has run through the existing things, we need to make a quick run-through the additions. For clarity, please put any new stuff at the end of the export list in package.lisp. I plan to run this on an approximately weekly cycle: unless there is controversy regarding the items under review, I'll post the next set of items next week, and so on. Actual review items coming in a separate thread. I post what I consider a manageable set of things to review in a one go, working through package.lisp. Then well talk about it -- both the thing itself (FOO is a good/bad/unnecessary thing to have / I don't understand FOO / FOO is nice, but doesn't belong in Alexandria because of X, etc.), the details of interface (FOO needs to use keyword arguments, FOO should be decomposed into multiple operators, FOO should signal an error when BAR happens, etc.), the docstring, the details of implementation, and the tests that go with it. ...in that approximate order. I don't think it is necessary to separate things into distinct phases unless there is controversy. In parallel with this, "obvious" fixes and improvements can be committed/pushed. Finally, we end up either with a blessed item, or a rejected item. ...and I maintain that I will consider Alexandria a roaring success if we manage to agree on ONCE-ONLY and WITH-GENSYMS/WITH-UNIQUE-NAMES and make 80% of projects needing them to use Alexandria. :) Cheers, -- Nikodemus

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[alexandria-devel] length=1
by Attila Lendvai 27 May '08

27 May '08

dear list, is there any objections against this? (declaim (inline length=1)) (defun length=1 (sequence) (if (listp sequence) (and sequence (null (rest sequence))) (= 1 (length sequence)))) in optimized code, where type information is available, it drops the type check. and otherwise it works for sequences and is fast for lists. maybe it could be extended into two functions: length= and length=1, where length= optimizes for lists using nthcdr. -- attila

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[alexandria-devel] DOSEQUENCE and WITH-SEQUENCE-ITERATOR
by Tobias C. Rittweiler 05 Apr '08

05 Apr '08

* sequences.lisp (dosequence): New macro. DOLIST analagon. (with-sequence-iterator): New macro. WITH-HASH-TABLE-ITERATOR analogon. (%make-sequence-iterator): New internal function. * package.lisp: Export DOSEQUENCE, and WITH-SEQUENCE-ITERATOR. * tests.lisp (dosequence.1): New test case. (with-sequence-iterator.1): Ditto. (with-sequence-iterator.2): Ditto. pullable from http://common-lisp.net/~trittweiler/darcs/alexandria/ -T.

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[alexandria-devel] [PATCH] COPY-HASH-TABLE
by Tobias C. Rittweiler 04 Apr '08

04 Apr '08

The following patch adds a :COPY-FN &key arg to COPY-HASH-TABLE which defaults to CL:IDENTITY. This way, you can specify if you want a shallow copy (default), or a customized one which is possibly deep to some arbitrary level. -T.

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[alexandria-devel] UNWIND-PROTECT-CASE
by Tobias C. Rittweiler 27 Mar '08

27 Mar '08

Sometimes it's desired to only do a certain cleanup operating in an UNWIND-PROTECT if a true transfer-of-control was issued in the protected-form. UNWIND-PROTECT-CASE can be used to conveniently control on what circumstances cleanup operations are supposed to be performed. (I think I've seen UNWIND-PROTECT-CASE on one of the Lisp machines, so it's actually prior art.) -T. (defmacro unwind-protect-case ((&optional abort-flag) protected-form &body clauses) "Like CL:UNWIND-PROTECT, but you can specify the circumstances that the cleanup CLAUSES are run. ABORT-FLAG is the name of a variable that will be bound to T in CLAUSES if the PROTECTED-FORM aborted preemptively, and to NIL otherwise. Examples: (unwind-protect-case () (protected-form) (:normal (format t \"This is only evaluated if PROTECTED-FORM executed normally.~%\")) (:abort (format t \"This is only evaluated if PROTECTED-FORM aborted preemptively.~%\")) (:always (format t \"This is evaluated in either case.~%\"))) (unwind-protect-case (aborted-p) (protected-form) (:always (perform-cleanup-if aborted-p))) " (check-type abort-flag (or null symbol)) (let ((gflag (gensym "FLAG+"))) `(let ((,gflag t)) (unwind-protect (multiple-value-prog1 ,protected-form (setf ,gflag nil)) (let ,(and abort-flag `((,abort-flag ,gflag))) ,@(loop for (cleanup-kind . forms) in clauses collect (ecase cleanup-kind (:normal `(when (not ,gflag) ,@forms)) (:abort `(when ,gflag ,@forms)) (:always `(progn ,@forms)))))))))

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[alexandria-devel] remove-from-plist
by Michael Weber 14 Mar '08

14 Mar '08

Below are three different implementations of remove-from-plist, all of which I find more aestetic than current alexandria's implementation. YMMV. I would favor the first one, which explicitly ditches error checking ("it's user responsibility", and a proper plist will be returned). In case somebody disagrees, the second implementation reintroduces it, albeit with a better error message. The third implementation checks for properness only at the end (outside the loop), while still being shorter than alexandria's implementation. I would also remove the FIXME, on grounds that if plists are long enough for that to matter, one shouldn't be using them anyway. (defun remove-from-plist (plist &rest keys) (loop for (key value) on plist by #'cddr unless (member key keys :test #'eq) collect key and collect value)) (defun remove-from-plist (plist &rest keys) (loop for (key . rest) on plist by #'cddr do (assert rest () "Expected a proper plist, got ~S" plist) unless (member key keys :test #'eq) collect key and collect (first rest))) (defun remove-from-plist (plist &rest keys) (loop with last = t for (key . rest) on plist by #'cddr do (setf last rest) unless (member key keys :test #'eq) collect key and collect (first rest) finally (assert last () "Expected a proper plist, got ~S" plist))) Cheers, Michael

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[alexandria-devel] Latest patches pullable from my new darcs repo
by Tobias C. Rittweiler 11 Mar '08

11 Mar '08

All the latest patches, and some more, are pullable via darcs pull http://common-lisp.net/~trittweiler/darcs/alexandria/ For your convenience, -T.

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[alexandria-devel] cdr 5
by Attila Lendvai 11 Mar '08

11 Mar '08

dear list, any objections against adding the types listed in cdr 5 to alexandria? it already has array-index and the rest seems useful, too. http://cdr.eurolisp.org/document/5/extra-num-types.html if noone does that before me and there's no objection either, i'll push it eventually. -- attila

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