Is there a CPAN module to parse nested parentheses?

Question

Is there a CPAN module that can read a string like this:

"[[<asdf>, <foo>], (abc, def, ghi), ({'jkl'})]"

...and parse it into some sort of tree structure that's easy to walk and pretty-print?

score 9 · Answer 1 · answered Dec 09 '08 at 22:23

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I think that you could build on top of Text::Balanced, which will do a lot of the heavy lifting for you. You'll still need to build a tree structure, though.

answered Dec 09 '08 at 22:23

Dave Rolsky

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score 4 · Answer 2 · answered Dec 10 '08 at 01:20

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Perl 5.10's regular expressions can handle balanced structures like that. See the (?PARNO) (?-PARNO) (?+PARNO) (?R) (?0) section in perlre.

answered Dec 10 '08 at 01:20

brian d foy

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score 2 · Answer 3 · answered Dec 09 '08 at 22:37

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Perl 6 is going to have built-in facilities to help support this. In the interim, Text::Balanced (as mentioned by Dave Rolsky) is probably the module of choice. Note that it, too, was written by Damian Conway (as commended by Bill Karwin).

answered Dec 09 '08 at 22:37

Jonathan Leffler

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score 1 · Answer 4 · edited Dec 10 '08 at 06:01

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Damian Conway's Parse::RecDescent

I haven't used this, but it's a good bet that a Perl module written by Damian Conway is worth using.

edited Dec 10 '08 at 06:01

cjm

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answered Dec 09 '08 at 21:28

Bill Karwin

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score 0 · Answer 5 · answered Dec 09 '08 at 21:58

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If the string is identical to the Data Dumper format, then it can be eval-ed back into the original structure.

answered Dec 09 '08 at 21:58

codelogic

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That's actually a neat idea, if you're sure the input is valid and all that. Thanks. Edit: Perl's auto-flattening would potentially lose a lot of info from the input though. – Sundar R Jul 24 '13 at 07:34

Is there a CPAN module to parse nested parentheses?

5 Answers5