alexandria-devel May 2008

alexandria-devel@common-lisp.net

4 participants
6 discussions

[alexandria-devel] darcs patch: Add #.#+ readtime conditional functions.
by asf＠boinkor.net 02 Oct '09

02 Oct '09

Mon Oct 16 10:00:31 CEST 2006 asf(a)boinkor.net * Add #.#+ readtime conditional functions. * This adds functions that can be used in #+#. readtime conditionals, for example: #+#.(alexandria:read-if (find-package :asdf-install)) :yay #+#.(alexandria:read-if-fbound :install :asdf-install :exportedp t) :yay * included in the patch is a commented-out portion that allows the user to activate a #? read syntax. I'm not sure if that fits into the conservativism constraints.

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[alexandria-devel] [PATCH] Fix for a bug in map-permutations
by Juan M. Bello Rivas 01 Aug '08

01 Aug '08

Hi, The function map-permutations wasn't working. The attached patch fixes it. Regards, -- Juan M. Bello Rivas

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[alexandria-devel] BISECT
by Samium Gromoff 07 Jun '08

07 Jun '08

Good day list, I believe the code below might meet the conservative standards of Alexandria. What do you think? (defun bisect (test n &optional (base 0)) "Find, using bisection, the largest positive integer below N and above, or equal to BASE, which satisfies TEST of one argument. Assumes monotonous truth value of TEST." (labels ((traverse (x fallback attack) (if (funcall test x) (cond ((zerop attack) x) ((= attack 1) (if (funcall test (1+ x)) (1+ x) x)) (t (rebalance x (1+ attack)))) (cond ((= fallback 1) (when (funcall test (1- x)) (1- x))) (t (rebalance (- x fallback) fallback))))) (rebalance (origin span &aux (middle (ash span -1))) (traverse (+ origin middle) middle (- span middle 1)))) (rebalance base (- n base)))) regards, Samium Gromoff

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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 May 2008