Re: matching the words

[roboticus]

venky4289:

What part are you having difficulty with?

If you haven't started at all, I'd suggest converting the words with underscores in them into regular expressions, and then searching through your dictionary.

...roboticus

When your only tool is a hammer, all problems look like your thumb.

[venky4289]

I have stored all the dictionary words into an array. . And all the words i need to search into another array. .. For example @array1=("fil_" , "t_xt"); words need to be filled @array2=("file","text","fils") words in dictionary file Now i need to match the elements of array1 with array2 and i should get the output as fil_ : file,fils T_xt : text Thanks for ur replies

[Kenosis]

Yes, that helped! Here's one option that substitutes the "_" with ".+" for use in a regex (use "." if you want only one letter to match):

use strict;
use warnings;

my @array1 = qw (fil_  t_xt _erl);
my @array2 = qw (Merlin file text fils perl filled);

for my $stem (@array1) {
    my $re = $stem;
    $re =~ s/_/.+/;
    /\b$re\b/ and print "$stem: $_\n" for @array2;
}

Output:

fil_: file
fil_: fils
fil_: filled
t_xt: text
_erl: perl

Only whole words are matched, as word boundires (\b) are used in the regex which, if omitted, will also match substrings within the dictionary words.

Hope this helps!

Update: Below is an updated version which adapts BrowserUk's preferred solution:

use strict;
use warnings;

my @array1 = qw (fil_  t_xt _erl);
my @array2 = qw (Merlin file text fils perl filled);

my $words = join ' ', @array2;

for my $stem (@array1) {
    my $re = $stem;
    $re =~ s/_/./;
    print "$stem: $1\n" while $words =~ /\b($re)\b/g;
}

Output:

fil_: file
fil_: fils
t_xt: text
_erl: perl

If you want the "_" to be matched by more than one letter in the dictionary words, change the substitution to $re =~ s/_/\\S+/;.

[BrowserUk]

Rather than loading the real words as an array, I'd load them as a single whitespace delimited string.

It is a couple of hundred times faster to invoke the regex engine, once, to search for one word in a string containing hundreds or thousands of words; than to invoke it hundreds or thousands of times to match against one word at a time:

#! perl -slw
use strict;
use Benchmark qw[ cmpthese ];

our $words = do{ local( @ARGV, $/ ) = 'words.txt'; <> };
our @words = split ' ', $words;

our $P //= 0.01;
our @toLookFor = map {
    rand() > $P ? ()
        :  do {
            my $w = $_;
            my $p = int( rand length()-1 );
            $w =~ s[.{$p}\K.][.];
            $w;
        };
} @words;

printf "Looking for %d terms amongst %d words\n",
    scalar @toLookFor, scalar @words;

cmpthese 1, {
    a => q[
        for my $re ( @toLookFor ) {
             m[^$re$]
                 #and print "a:$re :: $_"
                 for @words;
         }
    ],
    b => q[
        $words =~ m[\b($_)\b]
            #and print "b:$_ :: $1"
            for @toLookFor;
    ],
}

__END__
C:\test>junk42
Looking for 1846 terms amongst 178691 words
  s/iter     a     b
a   85.2    --  -95%
b   3.94 2065%    --

C:\test>junk42 -P=0.02
Looking for 3564 terms amongst 178691 words
  s/iter     a     b
a    166    --  -95%
b   7.83 2022%    --

cmpthese