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[alexandria-devel] Pending patches
by Tobias C. Rittweiler 01 Aug '08

01 Aug '08

There are still several patches pending in my repository: http://common-lisp.net/~trittweiler/darcs/alexandria/ The patches affect the following files: * alexandria.asd: Attila's LENGTH= implementation makes use of ARRAY-INDEX. So add a dependency between `types.lisp' and `sequences.lisp'. * functions.lisp: Make %COERCE-CALLABLE-TO-FUN notes go away. * lists.lisp: Add macro DO-PROPER-LIST, add function PROPER-LIST-LENGTH. Use them to guard against dotted and circular lists in several functions in `lists.lisp' and `sequences.lisp' (those who stated so in their docstrings.) * sequences.lisp: Fix MAP-COMBINATIONS. Add sequence iterators, i.e. WITH-SEQUENCE-ITERATOR and DOSEQUENCE. * hash-tables.lisp: Remove :KEY argument from COPY-HASH-TABLE; introduce MAP-HASH-TABLE instead. * modify-macros.lisp: New file; add CALLF &c.; Also add ENSUREF. -T.

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[alexandria-devel] Sequence Iterators.
by Tobias C. Rittweiler 12 Jul '08

12 Jul '08

Hi all, When writing complex functions that are supposed to work on sequences, one often laments about the lack of an iteration form that works on general sequences. I finished my work on sequence iterators to provide several abstractions to help writing such functions. The iterators are reasonably optimized, and result in performance that should be fast enough for virtually any purpose, especially on SBCL. The iterators are not extensible by any means, and only work on lists and vectors. My work provides the following macros: (with-sequence-iterator (name seq &key start end from-end) ...body...) Binds NAME to an iterator to iterate through SEQ from START to END, possibly in reversed order if FROM-END is T. (dosequence ((var idx) seq &key start end from-end) ...body...) Iterates through SEQ, binding VAR to the current element, and IDX to the current index of the current element. (dosequences (((var idx) seq &key start end from-end) &rest more) ...body...) Iterates through several sequences simultaneously. (dosequences* (((var idx) seq &key start end from-end) &rest more) ...body...) Similiarly to DOSEQUENCES, but iterates through the sequences in a more sequential manner. Cf. its docstring. (check-sequence-bounds seq start end &optional length) Signals an error if START, END are not valid bounding indices. (with-sequence-bounds ((seq-var seq) (start-var start) (end-var end) (length-var length)) ... body ...) Wrapper around CHECK-SEQUENCE-BOUNDS to bind the above vars to appropriate default values, check validity of indices, and declare some types. It can be found in my repository at http://common-lisp.net/~trittweiler/darcs/alexandria/ As a schmankerl (tidbit), here is an implementation of a function which tests whether a given sequence is the prefix of another given sequence: (defun begins-with-subseq (prefix sequence &key (test #'eql) (key #'identity) start1 end1 start2 end2) "Test whether the first elements of SEQUENCE are the same as the elements of PREFIX." (dosequences* ((p prefix t :start start1 :end end1) (s sequence nil :start start2 :end end2)) (unless (funcall test (funcall key p) (funcall key s)) (return nil)))) I hope you enjoy, -T.

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[alexandria-devel] Pushed
by Nikodemus Siivola 07 Jul '08

07 Jul '08

Mon Jul 7 11:51:14 EEST 2008 Nikodemus Siivola <nikodemus(a)random-state.net> * implement SIMPLE-PROGRAM-ERROR ...what is says on the tin. Mon Jul 7 11:55:06 EEST 2008 Nikodemus Siivola <nikodemus(a)random-state.net> * implement PARSE-ORDINARY-LAMBDA-LIST ...not something you need every day. Mon Jul 7 11:57:04 EEST 2008 Nikodemus Siivola <nikodemus(a)random-state.net> * implement MAKE-GENSYM, use similar logic in MAKE-GENSYM-LIST ...non-negative integers are arguments, and string designators instead of strings. Mon Jul 7 12:50:26 EEST 2008 Nikodemus Siivola <nikodemus(a)random-state.net> * explicitly export the CDR5 types from DEFPACKAGE ...so reloading package.lisp doesn't warn. Cheers, -- Nikodemus

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[alexandria-devel] io.lisp platform dependance
by Attila Lendvai 23 Jun '08

23 Jun '08

hi! io.lisp has some problems with regards to external-format, and i don't really know how to fix this. for now it only works on lisps that understand :exernal-format :default. the problem is that the external-format keyword arg is platform dependent, and so is its default value. we could add tons of various #+ conditionals, but that doesn't seem like a nice way to fix this. apply doesn't help much either, because with-open-file is a macro used inside a function. any ideas for a clean fix? -- attila

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[alexandria-devel] Reviewing control-flow.lisp; RfC to add ECOND, CCOND.
by Tobias C. Rittweiler 11 Jun '08

11 Jun '08

As control-flow.lisp is being reviewed, I'd like to suggest the incoporation of ECOND, and CCOND that do the obvious things. An implementation for ECOND is appended. -T. (defmacro econd (&body clauses) "ECOND works exactly like COND except if no test-form of the clauses evaluates to true, an error is signalled." `(cond ,@(append clauses (unless (loop for (clause-test . nil) in clauses thereis (member clause-test '(t otherwise))) `((t (error "ECOND -- fall through.")))))))

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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] symbolicate
by Attila Lendvai 05 Jun '08

05 Jun '08

hi, fyi, i've pushed symbolicate. irc rumour has it, that Nikodemus was pretty favorable to adding it... so, i hope it won't initiate a veto fury... :) it seemed to be the most forward looking way to fix cffi-grovel. -- attila

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[alexandria-devel] Re: approval request
by Marco Baringer 03 Jun '08

03 Jun '08

[resending to alexandria-devel(a)common-lisp.net] "Attila Lendvai" <attila.lendvai(a)gmail.com> writes: > 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? i approve. since the copyright notice at the end of io.lisp reads (in part): ;; - Redistributions of source code must retain the above copyright ;; notice, this list of conditions and the following disclaimer. ;; ;; - Redistributions in binary form must reproduce the above copyright ;; notice, this list of conditions and the following disclaimer in the ;; documentation and/or other materials provided with the distribution. i'm also rescinding these conditions. iow you do not need to keep my name and copyright in the copyright of alexandria, i'd appreciate it if you mentioned where you got the code from (so that any future patches could make their way back to arnesi) but you have no legal obligation to do so. -- -Marco Ring the bells that still can ring. Forget your perfect offering. There is a crack in everything. That's how the light gets in. -Leonard Cohen

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[alexandria-devel] approval request
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 publically? thanks in advance, - alexandria developer team

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[alexandria-devel] approval request
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? thanks is advance, - alexandria developer team

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