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Re: Logic trouble parsing a formatted text file into hashes of hashes (of hashes, etc.)

by idnopheq (Chaplain)
on Oct 18, 2004 at 16:49 UTC ( #400218=note: print w/ replies, xml ) Need Help??


in reply to Logic trouble parsing a formatted text file into hashes of hashes (of hashes, etc.)

Hi, All!

Thanks everyone for your tips. Taking bits from each, I created my own parser for the file.

#!/usr/bin/perl -wT #-*-cperl-*- use strict; my ( $laststate, $state, $nextstate ); open(SOURCE, "< $ARGV[0]") or die "Couldn't open $ARGV[0] for reading: $!\n"; # There are three possible line beginnings (ignoring whitespace): '(', + ':', and ')' # There are three possible line endings (ignoring whitespace): '(', ') +', and neither one while (<SOURCE>) { SWITCH: { # the first line in the file always starts with '(' # no other line will match this /^\(/ && do { $state = $laststate = 0; $nextstate = 1; # elevate the state last SWITCH; }; # lines beginning with ':' always have whitespace before it # these lines either maintain or elevate the state, never lower th +e state /^\s+:/ && do { $laststate = $state; $state = $nextstate; # here is where we analyse the line endings STATE: { # if the line ends with '(', elevate the state /\($/ && do { $nextstate++; last STATE; }; # if the line ends with ')', maintain the state? /\)$/ && do { last STATE; }; # other line endings elevate the state $nextstate++; } last SWITCH; }; # if the line contains only whitespace and ')', lower the state /^\s+\)$/ && do { $laststate = $state; $state--; $nextstate--; last SWITCH; }; } # analyse our state if ( $state != $laststate ) { # we changed state print "State Change!\t\t"; } print "$laststate\t$state\t$nextstate\n"; } close SOURCE;

I love the idea of DFA::Simple. The documentation for it sux, however. So I rolled my own based upon a review of my source file (which is still in idnopheq's scratchpad. Its just a shell so far. I'll move onto playing with real data now.

THX everone!
--
idnopheq
Apply yourself to new problems without preparation, develop confidence in your ability to to meet situations as they arrise.


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