April 2012 - cl-ppcre-devel@common-lisp.net

[cl-ppcre-devel] Using (unsigned-byte 8) instead of a (string) as TARGET-STRING
by Philipp Marek 26 Apr '12

26 Apr '12

Hello everybody, I've got a first (unoptimized) patch that allows to use (unsigned-byte 8) instead of a string as TARGET-STRING. My motivation is to use that for searching in big, binary files, which might not fit into RAM with byte => character conversion (which would be 1:4, as the binaries would have to be read as latin1 or similar). Using that patch on a ~3MB file with the string match at about 80% of the file size shows a nice speedup: only half to a third cpu time used, and much less memory usage (for the string). Details: -rw-r--r-- 1 root root 3176746 Mai 3 2010 /usr/share/doc/gcc-4.4-doc/gccint.html string, case-sensitive: 0.360022 seconds of total run time (0.360022 user, 0.000000 system) 907,556,608 processor cycles string, case-insensitive: 0.492031 seconds of total run time (0.492031 user, 0.000000 system) 1,239,853,076 processor cycles (unsigned-byte 8), case-sensitive: 0.108006 seconds of total run time (0.108006 user, 0.000000 system) 274,043,748 processor cycles (unsigned-byte 8), case-insensitive: 0.220013 seconds of total run time (0.220013 user, 0.000000 system) 553,027,836 processor cycles The small "problem" is this (one long line): $ time perl -e '$/=undef; $_=<>; print $1,$2,"\n" if /acr([o0] i)s not defined,\s+the default(\Dvalue,\s*\d+, i)s used/' < /usr/share/doc/gcc-4.4-doc/gccint.html o i value, 1, i real 0m0.016s user 0m0.004s sys 0m0.008s $ perl -v This is perl 5, version 14, subversion 2 (v5.14.2) built for x86_64-linux-gnu-thread-multi ie. (this) perl5 is still ~8 times faster, including file reading etc. (what the lisp code didn't take into the measurement). (With the /i modifier it's 0.020s.) I've not yet tried to run the whole test suite against that. There are quite a few warnings (unused variable UB8-MODE etc.) - but with higher SAFETY the original CL-PPCRE gave a lot of them, too. I'd like to ask for a quick look at the patch, to get some feedback; with the many duplications I don't really like the result, but the duplicated accesses ("schar" etc.) are too deeply integrated in cl-ppcre, I couldn't easily get them out into a single macro or something like that. Cyrus, Edi, could you help me clean up the changes so that they could be taken upstream? The other file is the one I'm using for testing. Regards, Phil

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[cl-ppcre-devel] sbcl unhandled exception
by Philipp Marek 19 Apr '12

19 Apr '12

Hello everyone, I'm trying to teach cl-ppcre (taken from github, updated) to use (unsigned-byte 8) data as well, to see how much faster it gets for ASCII and binary files. Attached is a diff that's my current state. It's not nice, but - it's not cleaned up yet. The problem is that with sbcl 1.0.55.0-debian (amd64) I get Unhandled memory fault at #x0. and that's not good. I'm doing this: (asdf:clear-system :cl-ppcre) (asdf:oos 'asdf:compile-op :cl-ppcre :force T) (asdf:oos 'asdf:load-source-op :cl-ppcre) then, optionally, (trace "CL-PPCRE") and then crash SBCL with (scan-to-strings "B(A+)(.)" "AAAAAABAAAAAAAAAA") Any ideas? Thanks a lot. Regards, Phil

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[cl-ppcre-devel] differing results between cl-ppcre and perl -- operator precedence?
by Cyrus Harmon 13 Apr '12

13 Apr '12

In trying to track down a problem matching a cxml-rng pattern in soiree, I came across the following somewhat odd behavior in cl-pppcre. In perl, I see: (sly@barbaresco):~/projects/soiree$ echo "Ta" | perl -ne 'print if /^T(a)|(b)$/' Ta (sly@barbaresco):~/projects/soiree$ echo "Tb" | perl -ne 'print if /^T(a)|(b)$/' Tb Whereas with cl-ppcre, I see: SOIREE-ICALENDAR> (cl-ppcre:scan-to-strings "^T(a)|(b)$" "Ta") "Ta" #("a" NIL) SOIREE-ICALENDAR> (cl-ppcre:scan-to-strings "^T(a)|(b)$" "Tb") "b" #(NIL "b") Parsing the string suggests that the order of operations may be different in cl-ppcre than in perl. Is this intentional? SOIREE-ICALENDAR> (cl-ppcre:parse-string "^T(a)|(b)$") (:ALTERNATION (:SEQUENCE :START-ANCHOR #\T (:REGISTER #\a)) (:SEQUENCE (:REGISTER #\b) :END-ANCHOR)) thanks, Cyrus

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[cl-ppcre-devel] omitting initial void string in split returns
by Mario Maio 13 Apr '12

13 Apr '12

I want to parse strings of space-separated integers, and split is perfect except when I have vertical aligned integers. In such cases I've got one or more spaces at beginning of string, and the resulting list has a void string as 1st element: CL-USER> (cl-ppcre:split "\\s+" " 43 76 87 33 89 ") ("" "43" "76" "87" "33" "89") Is there an option to avoid such initial void string? Thanks. Mario

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[cl-ppcre-devel] scan/property behavior?
by Cyrus Harmon 08 Apr '12

08 Apr '12

I was noticing some strange behavior with cxml-rng and David Lichteblau pointed out that the problem might be due to cl-ppcre and provided this example: (let ((regex1 '(:SEQUENCE :start-anchor (:greedy-repetition 0 42 (:property digit-char-p)) #\-)) (regex2 '(:SEQUENCE :start-anchor (:property digit-char-p) #\-)) (str "8-")) (values (multiple-value-list (ppcre:scan regex1 str)) (multiple-value-list (ppcre:scan regex2 str)))) Regex1 works as expected (it matches 8-) but the second one doesn't. It's possible I don't understand (well more than possible) how :property works, but I would have expected either both or neither of these to fail. Could this be due to a bug in cl-ppcre? thanks, Cyrus

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