Re: join() and split() to respect string overload operations

On Sat, Jun 05, 2010 at 08:01:37PM +0300, Yuval Kogman wrote:
> Why not just add a split method to your class? Seems like a lot of work for
> something that is a pretty high level idea anyway.

Well, it already contains a ->substr method.

I suppose I -could- write:

((caveat: untested, but this is the rough idea ;) ))

 sub split
 {
    my $self = shift;
    my ( $re ) = @_;

    my @points = ( 0 );
    while( $self =~ m/$re/g ) {
       push @points, $-[0], $+[0]
    }
    push @points, len $self;

    my @ret;
    while( @points ) {
       my $start = shift @points;
       push @ret, $self->substr( $start, shift(@points) - $start );
    }

    return @ret;
 }

However, observe that the -only- line at all relevant to String::Tagged
is the ->substr() line. If Perl were to provide a protocol, an
interface, a way for a subclass to declare "here is my substring
extraction method", then that line could be changed to use that generic
interface, and this entire method can become a useful function for -all-
strings or string-like objects, regardless of where they put their
substring extract method. I observe that  use overload substr => $METHOD
would be a convenient way for such a class to tell perl where it keeps
that code.

> With autobox you can even treat your strings and objects as pretty much the
> same thing.

I'm not sure I see how this is relevant in this case.

-- 
Paul "LeoNerd" Evans

[email protected]
ICQ# 4135350       |  Registered Linux# 179460
http://www.leonerd.org.uk/

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