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Answer 1

+4 A:

It seems like you would be much better off using a context-free grammar instead of a regular expression in this case. Consider using a parser generator, such as CUP or ANTLR.

Jay Conrod 2010-01-11 01:08:17

Woudn't be easy to match all with @AAA{ some text }} ?I don't know how to express: "some text"and at the end }}

aphex 2010-01-11 01:13:03

I think Anon's regular expression will get the text, but ONLY if nested braces are one-deep. A CFG will also make it easy to parse the individual statements inside the block.

Jay Conrod 2010-01-11 01:31:38

If you want to match more than one level of nesting, you have three options: Extend the regular expression to those deeper levels (assuming a finite depth), use a recursive (and thus nonregular) expression (Perl has these, don't know about Java), or use a proper parser.

Anon. 2010-01-11 01:40:13

Grats on all the upvotes, but it seems I found a simple regexp that satisfies the requirements ;)

Carl Smotricz 2010-01-11 08:35:37

Answer 2

+2 A:

If the nesting on braces is only allowed one-deep:

/@[A-Z]*{([^{}]*+|{[^{}]*+})*}/

Note the use of the possessive quantifier *+ - without it, this can take quite a long time on failed matches.

I'm not sure if Java supports it - if it doesn't, remove it, but keep in mind the poor failure-behaviour.

Anon. 2010-01-11 01:10:33

Is there anything in this expression or answer text making this expression multiline capable?

Carl Smotricz 2010-01-11 01:20:48

You don't need the leading and trailing slashes, the Regex constructor in Java just takes a regular String (so there are instances where you'll have to do double escaping but not in this case). Also, it does support possessive quantifiers so you won't have a problem there.

CurtainDog 2010-01-11 01:24:18

Would `[^{}]` in a Java regex match newlines by default? If not, the singleline attribute `/s` would need to be specified.

Anon. 2010-01-11 01:24:38

@Anon: I don't think so. That's why I asked.

Carl Smotricz 2010-01-11 01:41:05

Answer 3

A:

I would not use regex, I would tokenize the string and build up a dictionary. Sorry, this is a Python implementation (not Java):

>>> s ="""@AAAA{tralala10aa,
  author = {Some Author},
  title = {Some Title},
  booktitle = {Some Booktitle},
  year = {2010},
  month = {March},
  booktitle_short = {CC 2010},
  conference_url = {http://www.mmmm.com},
  projects = {projects}
}"""
>>> 
>>> s
'@AAAA{tralala10aa,\n  author = {Some Author},\n  title = {Some Title},\n  booktitle = {Some Booktitle},\n  year = {2010},\n  month = {March},\n  booktitle_short = {CC 2010},\n  conference_url = {http://www.mmmm.com},\n  projects = {projects}\n}'
>>> 
>>> 
>>> lst = s.replace('@AAA', '').replace('{', '').replace('}', '').split(',\n')
>>> lst
['Atralala10aa', '  author = Some Author', '  title = Some Title', '  booktitle = Some Booktitle', '  year = 2010', '  month = March', '  booktitle_short = CC 2010', '  conference_url = http://www.mmmm.com', '  projects = projects\n']
>>> dct = dict((x[0].strip(), x[1].strip()) for x in (y.split('=') for y in lst[1:]))
>>> dct
{'booktitle_short': 'CC 2010', 'title': 'Some Title', 'booktitle': 'Some Booktitle', 'author': 'Some Author', 'month': 'March', 'conference_url': 'http://www.mmmm.com', 'year': '2010', 'projects': 'projects'}
>>> 
>>> dct['title']
'Some Title'
>>>

Hopefully the code above seems self explanatory.

Hamish Grubijan 2010-01-11 01:12:29

-1 - this doesn't answer this (clearly) Java-specific question.

Stephen C 2010-01-11 01:18:18

Nevertheless, it is a better solution than using a regexp.

quant_dev 2010-01-11 01:20:50

@quant_dev - if you think dictionaries are a better way to solve the problem, code the solution in Java and post it as your own answer.

Stephen C 2010-01-11 01:31:30

Answer 4

+2 A:

If the "block" always ends with a lone closing brace, then this ~~may~~will do it:

"(?ms)@[A-Z]+\\{.+?^\\}$"

Where (?ms) sets the expression to "multiline" and "dotall" (so the .+ can also match newlines), and the stuff at the end matches a closing brace on a line by itself.

The question mark in the middle makes the .+ match non-greedy so it won't match all blocks up to and including the last block in the file.

Carl Smotricz 2010-01-11 01:14:41

It doesn't work. When i have more blocks it matches them all as one.

aphex 2010-01-11 01:27:08

Oops, sorry! I just corrected a bug in my expression. Please try again!

Carl Smotricz 2010-01-11 01:39:14

It works perfect :) Thanks very much !

aphex 2010-01-11 02:35:42

Excellent! Thank you for the feedback, I'd been chewing my nails here.

Carl Smotricz 2010-01-11 08:33:05

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