#!/usr/bin/perl
use strict;
use re 'eval';
my $Jscript = join (" ",<DATA>);
# Extract function foo from Jscript
my $content = _extract("foo",$Jscript);

sub _extract {
    my ($funct,$Jscript) = @_;

    #regexes to match all but starting positions of strings and comments 
    my $double_quote_str = qr!(\\.|[^"\\])*"!;
    my $single_quote_str = qr!(\\.|[^'\\])*'!;
    my $comment1 = qr![^\n\r]*!;
    my $comment2 = qr!.*?\*/!s;    
    
    #now match complete strings or comments..whatever matches first will 'eat' others
	my $escape_strings = qr!
        
        (   
            '(?{$start='sing_quot'})|
             "(?{$start='dbl_quot'})|
            //(?{$start='comment1'})|
            /\*(?{$start='comment2'})
        )
        (?(?{$start eq 'sing_quot'})$single_quote_str)
        (?(?{$start eq 'dbl_quot'})$double_quote_str)
        (?(?{$start eq 'comment1'})$comment1)
        (?(?{$start eq 'comment2'})$comment2)
        
    !x;

    my ($round,$curly);
	
    # match balanced nested round braces ..escape strings and comments
    $round = qr!
    \((
        $escape_strings  
        |
        [^()]|(??{$round})
      )*
    \)
    !x;
	
    # match balanced nested curly braces ..escape strings and comments
    $curly = qr!
    { (
        $escape_strings
        |
        [^{}]|(??{$curly})
      )*
    }
    !x;
     
    if ($Jscript =~ m!(\bfunction\s+$funct\s*$round\s*$curly)!) {
        print "Matched :\n",$1;
    } 
}

__DATA__

//.. function foo goes here .......