That's great. Here's the outline for code that does exactly that. It passes a postponing object to overload::constant, postpones any concatenation and then runs the actual conversion function on stringification at the end.

package My::Package;
use strict;
use warnings;

sub convert {
    YOUR CODE GOES HERE
}

use overload( '.' => \ &_concat,
              '""' => \ &_finalize );

sub import { overload::constant qr => \ &_postpone; }
sub _postpone {
    my $re = shift;
    bless \ $re, __PACKAGE__;
}
sub _concat {
    my ( $a, $b, $inverted ) = @_;
    ($a,$b)=($b,$a) if $inverted;
    $a = $$a if ref( $a ) eq __PACKAGE__;
    $b = $$b if ref( $b ) eq __PACKAGE__;
    
    my $re = "$a$b";
    bless \ $re, __PACKAGE__;
}
sub _finalize {
    @_ = ${shift()};
    &convert;
}


1;

[download]

In reply to Re^2: overload::constant passes fragments, not whole strings under interpolation. Help? by diotalevi
in thread overload::constant passes fragments, not whole strings under interpolation. Help? by diotalevi

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.