Hello Monks,

Long time no see! Recently I have to parse a file and export to another format. the original file is like this: 

Y 034309201607258   1        #Y means header
Q     02751VACANT / CLOSE    #comment
G   ....            # inner head
...
...
...                          
T RCRC   0810010
T RDRD   0810010
A 22OP
A 13O 
A 12O 
P 3472CHSK00010014 #P means inner trailer
Z 034309201607258  #Z means trailer

[download]
I took this weekend to learn P::RD, and seems a little bit to understand it. but when I tried some snippet to run, it's hard to succeed as I image: 
use Parse::RecDescent;
  use IO::All;

  my $text = io("xxx.DAT")->slurp;
  # Create and compile the source file
  $parser1 = Parse::RecDescent->new(q(
    startrule : HeadRule /.+/ms TrailerRule 

    HeadRule : /^Y.+$/m
    TrailerRule: /^Z.+$/m
  ));

  $parser2 = Parse::RecDescent->new(q(
    startrule : HeadRule 

    HeadRule : /^Y.+^Z.+$/ms

  ));


# Test it
  print "Valid data\n" if $parser1->startrule($text); #no!
  print "Valid data\n" if $parser2->startrule($text); #yes

[download]
why parser1 is failed? and in order to learn P::RD, Could anyone tell me if some module parsing files( like xml or html etc> on cpan make use of P:RD?

Thanks


I am trying to improve my English skills, if you see a mistake please feel free to reply or /msg me a correction

In reply to question when learning P::RD? by xiaoyafeng

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