Comments on: Clojure’s new regex syntax http://items.sjbach.com/406/clojures-new-regex-syntax Fri, 19 Feb 2010 12:11:08 -0800 http://wordpress.org/?v=2.8.5 hourly 1 By: Clojure Roundup: Post-Thanksgiving vacation edition « Clojure Study Group DC http://items.sjbach.com/406/clojures-new-regex-syntax/comment-page-1#comment-976 Clojure Roundup: Post-Thanksgiving vacation edition « Clojure Study Group DC Mon, 01 Dec 2008 14:05:28 +0000 http://items.sjbach.com/?p=406#comment-976 [...] Clojure recently incorporated a new regex syntax. [...] [...] Clojure recently incorporated a new regex syntax. [...]

]]> By: greg http://items.sjbach.com/406/clojures-new-regex-syntax/comment-page-1#comment-73 greg Thu, 20 Nov 2008 00:06:37 +0000 http://items.sjbach.com/?p=406#comment-73 (unicode categories are also useable, i.e <code>\p{P}</code> for all unicode punctuation signs or <code>\p{Lu}</code> for all uppercase letters and so on) (unicode categories are also useable, i.e \p{P} for all unicode punctuation signs or \p{Lu} for all uppercase letters and so on)

]]> By: greg http://items.sjbach.com/406/clojures-new-regex-syntax/comment-page-1#comment-72 greg Thu, 20 Nov 2008 00:01:39 +0000 http://items.sjbach.com/?p=406#comment-72 In the Java RE engine, you also have other predefined classes, such as <code>\p{Alpha}</code> or <code>\p{ASCII}</code> and so on - see: http://java.sun.com/j2se/1.4.2/docs/api/java/util/regex/Pattern.html These imo provide readability (although I hate the <code>\p</code> prefix, <code>{Alone}</code> would be nice and leave out confusion of the syntax proposed here with square brackets which look too much like "custom" classes) and Unicode support (<code>\p{InArbitraryUnicodeBlock}</code> for instance) In the Java RE engine, you also have other predefined classes, such as \p{Alpha} or \p{ASCII} and so on – see:
http://java.sun.com/j2se/1.4.2/docs/api/java/util/regex/Pattern.html

These imo provide readability (although I hate the \p prefix, {Alone} would be nice and leave out confusion of the syntax proposed here with square brackets which look too much like “custom” classes) and Unicode support (\p{InArbitraryUnicodeBlock} for instance)

]]> By: Stephen Bach http://items.sjbach.com/406/clojures-new-regex-syntax/comment-page-1#comment-70 Stephen Bach Wed, 19 Nov 2008 18:47:10 +0000 http://items.sjbach.com/?p=406#comment-70 Chaitanya, I am suitably corrected. I've updated the article -- Edi certainly deserves his due. Thanks. doug, thanks! Johan: fixed it up for you. :-) And I agree, Perl is the big winner here. Chaitanya, I am suitably corrected. I’ve updated the article — Edi certainly deserves his due. Thanks.

doug, thanks!

Johan: fixed it up for you. :-) And I agree, Perl is the big winner here.

]]> By: Johan L http://items.sjbach.com/406/clojures-new-regex-syntax/comment-page-1#comment-69 Johan L Wed, 19 Nov 2008 18:32:18 +0000 http://items.sjbach.com/?p=406#comment-69 Great, the lack of indentation made the last example look like crap. Oh, well... Great, the lack of indentation made the last example look like crap. Oh, well…

]]> By: Johan L http://items.sjbach.com/406/clojures-new-regex-syntax/comment-page-1#comment-68 Johan L Wed, 19 Nov 2008 18:30:56 +0000 http://items.sjbach.com/?p=406#comment-68 The most readable Perl regexes are written with the <code>/x</code> modifier so you can have whitespace in it. That also makes it possible to write the regex on multiple lines with proper indentation and use <code>#</code> comments. (the data doesn't quite seem to match the regexes). <pre> m| <img \s+ src="\w+ / \d+ / (\w+) |x </pre> or even: <pre> m| <img \s+ src="\w+ # Initial word (something) / \d+ # Bogus number / (\w+) # Capture basename |x </pre> Yeah, Perl is just so much line noise... The most readable Perl regexes are written with the /x modifier so you can have whitespace in it. That also makes it possible to write the regex on multiple lines with proper indentation and use # comments.

(the data doesn’t quite seem to match the regexes).

m| <img \s+ src="\w+  /  \d+  /  (\w+) |x

or even:

m|
    <img \s+
        src="\w+  # Initial word (something)
        / \d+     # Bogus number
        / (\w+)   # Capture basename
|x

Yeah, Perl is just so much line noise…

]]> By: doug http://items.sjbach.com/406/clojures-new-regex-syntax/comment-page-1#comment-67 doug Wed, 19 Nov 2008 18:25:54 +0000 http://items.sjbach.com/?p=406#comment-67 For the record, Python is pretty clear too: <code>r'<img\s+src="\w+/\d+/(\w+)'</code> For the record, Python is pretty clear too: r'<img\s+src="\w+/\d+/(\w+)'

]]> By: Chaitanya Gupta http://items.sjbach.com/406/clojures-new-regex-syntax/comment-page-1#comment-66 Chaitanya Gupta Wed, 19 Nov 2008 17:29:34 +0000 http://items.sjbach.com/?p=406#comment-66 Wanted to make the same point as Peter -- Edi's cl-interpol+cl-ppcre is a great combination if you deal with regexes in CL a lot. Wanted to make the same point as Peter — Edi’s cl-interpol+cl-ppcre is a great combination if you deal with regexes in CL a lot.

]]> By: Stephen Bach http://items.sjbach.com/406/clojures-new-regex-syntax/comment-page-1#comment-65 Stephen Bach Wed, 19 Nov 2008 17:02:52 +0000 http://items.sjbach.com/?p=406#comment-65 Peter, thanks! I was aware of CL-INTERPOL, but I've never used it and didn't know of its "synergy" with CL-PPCRE. Matt, looks nifty, and I agree, more Lisp-like. Peter, thanks! I was aware of CL-INTERPOL, but I’ve never used it and didn’t know of its “synergy” with CL-PPCRE.

Matt, looks nifty, and I agree, more Lisp-like.

]]> By: Matt Might http://items.sjbach.com/406/clojures-new-regex-syntax/comment-page-1#comment-64 Matt Might Wed, 19 Nov 2008 16:21:23 +0000 http://items.sjbach.com/?p=406#comment-64 Certainly a big improvement, but I've always preferred Scheme Shell's S-Expression-based regex syntax for flavors of Lisp. Certainly a big improvement, but I’ve always preferred Scheme Shell’s S-Expression-based regex syntax for flavors of Lisp.

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