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=head1 METHODS

=head2 compare( ARG1, ARG2, OPTIONAL_CALLBACK )

You can call compare with either two strings compare( $str1, $str2 ):

    my ( $av_similarity,
         $sim_str1_to_str2,
         $sim_str2_to_str1,
         $matches,
         $in_str1_but_not_str2,
         $in_str2_but_not_str1
       ) = compare( 'this is a string-a', 'this is a string bbb' );

Note that the mathematical similarities of one string to another will be
different unless the strings have the same length. The first result returned
is the average similarity. Totally dissimilar strings will return 0. Identical
strings will return 1. The degree of similarity therefore ranges from 0-1 and
is reported as the biggest float your OS/Perl can manage.

You can also compare two array refs compare( \@ary1, \@ary2 ):

    my ( $av_similarity,
         $sim_ary1_to_ary2,
         $sim_ary2_to_ary1,
         $ref_ary_matches,
         $ref_ary_in_ary1_but_not_ary2,
         $ref_ary_in_ary2_but_not_ary1
       ) = compare( [ 1,2,3,4 ], [ 3,4,5,6,7 ] );


When called with two string you can specify an optional callback that changes
the default tokenization of strings (a simple split on null) to whatever you
need. The strings are passed to you callback in $_ and the sub is expected to
return an array ref. So for example to ignore all
whitespace you could:

    @res = compare( 'this is a string',

html/HowSimilar.html  view on Meta::CPAN

<HR>
<H1><A NAME="methods">METHODS</A></H1>
<P>
<H2><A NAME="compare( arg1, arg2, optional_callback )">compare( ARG1, ARG2, OPTIONAL_CALLBACK )</A></H2>
<P>You can call compare with either two strings compare( $str1, $str2 ):</P>
<PRE>
    my ( $av_similarity,
         $sim_str1_to_str2,
         $sim_str2_to_str1,
         $matches,
         $in_str1_but_not_str2,
         $in_str2_but_not_str1
       ) = compare( 'this is a string-a', 'this is a string bbb' );</PRE>
<P>Note that the mathematical similarities of one string to another will be
different unless the strings have the same length. The first result returned
is the average similarity. Totally dissimilar strings will return 0. Identical
strings will return 1. The degree of similarity therefore ranges from 0-1 and
is reported as the biggest float your OS/Perl can manage.</P>
<P>You can also compare two array refs compare( \@ary1, \@ary2 ):</P>
<PRE>
    my ( $av_similarity,
         $sim_ary1_to_ary2,
         $sim_ary2_to_ary1,
         $ref_ary_matches,
         $ref_ary_in_ary1_but_not_ary2,
         $ref_ary_in_ary2_but_not_ary1
       ) = compare( [ 1,2,3,4 ], [ 3,4,5,6,7 ] );</PRE>
<P>When called with two string you can specify an optional callback that changes
the default tokenization of strings (a simple split on null) to whatever you
need. The strings are passed to you callback in $_ and the sub is expected to
return an array ref. So for example to ignore all
whitespace you could:</P>
<PRE>
    @res = compare( 'this is a string',
                    'this is a string ',
                    sub { s/\s+//g; [split //] }