Method returning a regex in Perl 6?

Question

I'm only beginning to study classes, so I don't understand the basics.

I want a method to construct regex using attributes of the object:

class TEST {
    has Str $.str;

    method reg {
        return 
            rx/
               <<
               <[abc]> *
               $!str
               <!before foo>
              /;
    }         
}   

my $var = TEST.new(str => 'baz');
say $var.reg;

When trying to run this program, I get the following error message:

===SORRY!=== Error while compiling /home/evb/Desktop/p6/e.p6
Attribute $!str not available inside of a regex, since regexes are methods on Cursor.
Consider storing the attribute in a lexical, and using that in the regex.
at /home/evb/Desktop/p6/e.p6:11
------>                <!before foo>⏏<EOL>
    expecting any of:
        infix stopper

So, what's the right way to do that?

Answer 1

Looks like this would work:

class TEST {
    has Str $.str;

    method reg {
        my $str = $.str;
        return 
            regex {
               <<
               <[abc]> *
               $str
               <!before foo>
               }
    }         
}   

my $var = TEST.new(str => 'baz');
say $var.reg;
say "foo" ~~ $var.reg;
say "<<abaz" ~~ $var.reg

You are returning an anonymous regex, which can be used as an actual regex, as it's done in the last two sentences.