NAME

String::Pattern - create / identify strings by pattern

SYNOPSIS

        use String::Pattern;
        use strict;

        my $code = "73545-ved-8877";
        my $name = "Benalgin";
        my $prescription = 'X';
        my $price = 10.99;
        my $date;

        my $p = new Pattern 'code: 1223144-x-67 name: Aspirin prescription: [pr_flag] price: $5.90';
        my $print_view = new Pattern q{
                record date : 8/11/00
                code: 1223144-x-67
                name: Aspirin
                [pr_flag] prescription
                price: $5.90
        };

        $p->bind( '1223144-x-67' => \$code);
        $p->bind( Aspirin => \$name);
        $p->bind( '5.90' => \$price, '\d+(?:[,\.]\d{2})?');
        $p->bind( pr_flag => \$prescription);
        $print_view->bind_like($p);
        $print_view->bind( '8/11/00' => \$date);
        
        my $q="$p"; # equivalent ot my $q=$p->to_string;

        $prescription=" ";
        my $r = 'code: 1223144x-69 name: Aspirin-Bayer prescription: [ ] price: $3.124';

        for my $string ($r,     $p,     $q) {
                print $string, "\n";
                if ($p->identify($string)) {
                        print "Match on pattern \n";
                        $date = localtime;
                        print $print_view."\n";
                }else{
                        print "Not match on pattern \n\n"
                }
        }

DESCRIPTION

This module is designed to deal whith non atomic data strings representations whith fixed number of items on it - such as addresses, business cards, product descriptors etc. It simplificies string creation based on preliminary defined human readable patterns ( templates ) and identifying that any given string has format, "described" in the same pattern.

Methods

pattern

pattern ($string)

if $string is supplied then it will be used as pattern, otherwise currently used pattern is returned

bind ( tag => \$var)

bind ( tag => \$var, $re)

binds var ref to specific part of pattern (tag). When string is created, all occuriences of that tag will be replaced with the value of $var. Regular expession $re is used to describe what the tag looks like, and increases the accuracy of identify method in ambiguous cases. Pattern is used to build one regular expession whith backreferences ( for each occurrence of tag ) , so brackets usage in $re must be only like this (?: ... ).

to_string

Creates string based on pattern and bindings. This method is invoked when object ref is evaluated in string context

identify ($string)

Returns 1 if $string matches on pattern and all occurrences of given tag are equal, then sets vars to first occurrence of respective bounded tag. Otherwise returns 0 and nothig is changed.

bind_like ($other_pattern_object)

Gets bindings from other object. May be useful for copy like operations avoiding boring declararions.

        my $p1 = new String::Pattern .....;
        my $p2 = new String::Pattern .....;

        # a lot of bind ...
        $p1->bind....;
        ...
        $p1->bind....;
        $p2->bind_like($p1);

        # $p2 specific binds
        $p2->bind....;
        
        if ($p1->identify(...)) {
                print $p2
        }

so $p2 have all of $p1 bindings plus one additional

to do

erros and warnings: Adding some useful warnings and erros about content of variables, and their ralations with tags in the pattern

AUTHOR

Ivo Zdravkov, ivoz@starmail.com