Perl/Python regular expressions vs. Boost.regex?

[skip@pobox.com]

A colleague wrote a C++ library here at work which uses the Boost.regex
library. I quickly discovered an apparent problem with how it searches.
Unlike re.match the regex_match function in that library effectively anchors
the match at both the start and the end. Can other people confirm this?

Thx,

Skip Montanaro

[Rob Williscroft]

Re: Perl/Python regular expressions vs. Boost.regex?

wrote in news:mailman.29 06.1224773327.3 487.python-list@python.org in
comp.lang.pytho n:

A colleague wrote a C++ library here at work which uses the
Boost.regex library. I quickly discovered an apparent problem with
how it searches. Unlike re.match the regex_match function in that
library effectively anchors the match at both the start and the end.
Can other people confirm this?
>
Thx,
>
Skip Montanaro
>

Quoting from : <url:http://www.boost.org/doc/libs/1_36_
0/libs/regex/doc/html/boost_regex/ref/regex_match.htm l>

<quote>
Important

Note that the result is true only if the expression matches the whole of
the input sequence. If you want to search for an expression somewhere
within the sequence then use regex_search. If you want to match a prefix of
the character string then use regex_search with the flag match_continuou s
set.

</quote>

So yes it does.

Rob.
--

http://www.victim-prime.dsl.pipex.com/

[skip@pobox.com]

Re: Perl/Python regular expressions vs. Boost.regex?


RobQuoting from : <url:http://www.boost.org/doc/libs/1_36_0/libs/regex/doc/html/boost_regex/ref/regex_match.htm l>

Rob<quote>
RobImportant

RobNote that the result is true only if the expression matches the
Robwhole of the input sequence. If you want to search for an
Robexpression somewhere within the sequence then use regex_search. If
Robyou want to match a prefix of the character string then use
Robregex_search with the flag match_continuou s set.

Rob</quote>

RobSo yes it does.

Thanks. I'll try and convince my colleague to use regex_search instead of
regex_match.

Skip