[erlang-questions] Problems with re:replace/4

[Antoine Koener]

Why using 'named matches ' instead of \\1 ?
since you use ( ) in the search motif ?



On 22 juil. 2011, at 09:56, Paul Burt <paul.burt@REDACTED> wrote:

> Sadly not, no. I tried that.
> 
> The replacement string simply returns the literal string "\k<mention>"
> or "\\k<mention>" no matter how many backslashes I put in!
> 
> Cheers,
> Paul
> 
> 
> On 22 July 2011 08:51, Antoine Koener <antoine.koener@REDACTED> wrote:
>> Whenever you deal with re module and the \ character, try \\ instead.
>> 
>> There's 2 levels of filtering.
>> 
>> Maybe this will help :))
>> 
>> 
>> 
>> On 22 juil. 2011, at 09:39, Paul Burt <paul.burt@REDACTED> wrote:
>> 
>>> Hi,
>>> 
>>> I'm a newcomer to Erlang and am interested in writing some helper
>>> functions to parse and manipulate responses from the Twitter API for
>>> use in a web application.
>>> 
>>> What I would like to do is replace "@mention" and "#hashtag" with HTML
>>> markup as follows:
>>> 
>>> @mention --> <a href="http://twitter.com/mention">@mention</a>
>>> #hashtag --> <a href="http://search.twitter.com/search?tag=hashtag">#hashtag</a>
>>> 
>>> In other words transform Twitter @mentions and #hashtags into clickable links.
>>> 
>>> I have the basic structure of a function (tweetify/1) to do this
>>> below. The ???? represent where I'm running into trouble:
>>> 
>>> tweetify(Input) ->
>>>    Replacements = [
>>>        {"@(?<mention>\\w+)", "<a href=\"http://twitter.com/????\">&</a>"},
>>>        {"#(?<hashtag>\\w+)", "<a
>>> href=\"http://search.twitter.com/search?tag=????\">&</a>"}
>>>    ],
>>>    lists:foldl(fun({RE, Replacement}, Tweet) ->
>>>                      re:replace(Tweet, RE, Replacement, [global,
>>> {return, binary}])
>>>                  end, Input, Replacements).
>>> 
>>> Whilst I understand that the token "&" will insert _everything_
>>> matched by the regular expression (i.e. @mention and #hashtag
>>> respectively), how do I use the named tags in the replacement string?
>>> In other words, how do I get hold of \k<mention> and \k<hashtag> in
>>> the PCRE idiom and use them in the replacement string?
>>> 
>>> Thanks in advance for any assistance/pointers.
>>> 
>>> -Paul
>>> _______________________________________________
>>> erlang-questions mailing list
>>> erlang-questions@REDACTED
>>> http://erlang.org/mailman/listinfo/erlang-questions
>> 
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