in reply to Re: pattern matching
in thread pattern matching

#!/usr/bin/perl -w %hash = (); open(FILE, "story.txt") || die ; #opens file story.txt while ( $story[$i++] = <FILE> ){ } #moves story.txt to @story close (FILE); #closes Story.txt foreach $list ( @story ) { @temp = split(/ /, $list); #puts word by word in @temp $i=0; while ($i <= $#temp) { $word=$temp[$i]; if ( $word =~ /^\[/ && $word =~ /$\]/) { if (! exists $hash { $word } ) { $auxiliary_word = $word; $auxiliary_word =~ tr/\[/ /; #removes front bracket $auxiliary_word =~ tr/\].,?/ /; #removes rear bracket & pu +nctuation $capitol = 0; if ($word =~ /^\[[A-Z]/) #checks for capitol letter { $capitol = 1; } Replace($word,$capitol); #function call to enter own word +s } } $i++; } } Print(); #print final madlib story #***************************************************************** sub Replace #user enters own words { print" Please enter a $auxiliary_word: "; $new_word = <STDIN>; if ($capitol == 1 ) { $new_word =~ s/(^[a-z]+)/\u$1/; #makes first letter capitol } chomp ( $new_word ); $hash { $word } = $new_word; #adds capitol letter t +o hash } #********************************************************************* sub Print #function to print new story { foreach $list ( @story ) { @temp = split(/ /, $list); $i=0; while ($i <= $#temp) { $word = $temp[$i]; if ($word =~ /^\[/ && $word =~ /$\]/) #if ( $word =~ m/\B[[A-Za-z]]/g) { $temp[$i] = $hash { $word }; } $i++; } $final = join(' ', @temp); #joins story together print $final; #prints new story } }
Strangeness in Cars I once owned a [noun] that was [adjective] only when , in a [Make-of-car]. Some [plural-noun] thought, [adverb], that this was [another-adjective], but what did they [verb]. Anyway, now I am [comparative], and don't [verb] so much, even when in [make-of-car] cars. Do you think that's [another-adjective], or should I [strange-action-verb]?

Replies are listed 'Best First'.
Re: Re: Re: pattern matching
by dws (Chancellor) on Feb 25, 2003 at 21:27 UTC
    You can reduce the code quite a bit by playing to Perl's strengths. The quick way to load the story into an array (once you've opened the file) is
    my @story = <FILE>;
    You can reduce the amount of work you're doing to pull out bracketed words by doing
    foreach my $line ( @story ) { $line =~ s/\[([A-Za-z-]+)\]/Replace($1)/eg; }
    This replaces each bracketed work with whatever Replace() returns for that word. The /eg modifiers on the regular expression say to replace whatever is found with the results of executing (/e) the expression on the right-hand side, and to repeat this match "globally" (/g) across the target string. And, because $line is "aliased" to each row in @story, you don't need to make a second pass through @story.

    Then, to print the story

    print @story;
    Now, you've localized all of the interesting work to
    sub Replace { my $word = shift; ... }
    which I'll leave as an exercise.

Re: Re: Re: pattern matching
by graff (Chancellor) on Feb 26, 2003 at 02:58 UTC
    One (perhaps main) reason your script didn't work as intended can be found on this line:
    if ($word =~ /^\[/ && $word =~ /$\]/)
    I think you're trying to use the dollar sign in the second regex to mean "if the word ends with a close-square-bracket", but since the dollar sign there is supposed to mean "end of string", you're supposed to place it at the end of the pattern, like this:
    if ($word =~ /^\[/ && $word =~ /\]$/)
    But as others have pointed out, there is room for quite a few other improvements to the code...