Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl: the Markov chain saw
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
Argh, it's driving me nuts.

I am using Parse::RecDescent to parse a meta language, and it is pretty much working, but I am having trouble with quoted strings. I have searched all around and can't find any good documentation on it.

In the P::RD docs it shows a parser for parsing P::RD grammars, and in that it shows { extract_quotelike($text) } being used as a rule. This doesn't do exactly what I want, since I only want ' and ", but it was close enough. I put it in my grammar like so:

string: { $_ = extract_quotelike($text); chop; substr($_,0,1,''); $_; +} { [@item] }
and it works, I realize its probably not right, especially since I get lots of warnings for use of uninitialized values. When I tried to change my code to something more proper and kill the warnings, however, my grammar no longer works. I tried:
string: { extract_quotelike($text) }
and it changes the way the whole grammar works

In fact if I change it to:

string: { $_ = extract_quotelike($text); if($_) { chop; substr($_,0,1, +''); } $_; } { [@item] }
it breaks it as well... which really confuses me.

So, my real question is in two parts
1) how do you use the extract_quotelike in P::RD (I looked all through the docs for an explanation of what rule: { <code> } is supposed to do, but I can't find it. Is it undocumented or am I blind?)
2) Is there a better way to match a string with just single or double quotes?

                - Ant
                - Some of my best work - (1 2 3)


In reply to Quoted Text rule for Parse::RecDescent? by suaveant

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others wandering the Monastery: (11)
    As of 2015-07-07 22:56 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









      Results (93 votes), past polls