NAME
    String::Interpolate::Delayed - delay string interpolation until you
    really want it

SYNOPSIS
       use strict;
       use warnings;
       use String::Interpolate::Delayed;
   
       my $str   = delayed "$role of the $thing";
       my $role  = "Lord";
       my $thing = [qw( Rings Flies Dance )]->[rand 3];
   
       print "$str\n";

DESCRIPTION
    This module allows you to create strings which are interpolated, but not
    immediately.

    Running the code in the SYNPOSIS will print the name of one of my
    favourite lords, even though at the time $str was declared, the
    variables $role and $thing had still not been declared!

  Discussion
    How does this pass strictures? You might expect that the line which
    declares $str would trigger a compile-time error, as it refers to two
    variables which don't exist. Fear not! "delayed" is technically a
    quote-like operator, not a function; the string following it is parsed
    by Perl as an *uninterpolated* string, even if it appears in double
    quotes. We could equally have written:

       my $str = delayed/$role of the $thing/;

    I prefer the double-quoted style because it fares better with syntax
    highlighting.

    What is $str? It's actually a blessed object, but it uses UNIVERSAL::ref
    to conceal this fact. ("blessed" from Scalar::Util knows the truth
    though.)

    And it overloads stringification, right? By George! You've got it! Yes,
    it overloads stringification and plays silly games with PadWalker and
    String::Interpolate.

  Methods
    As mentioned above, strings with delayed interpolation are blessed
    objects. As such, they have methods:

    "new($text)"
        Object-oriented way to create a string with delayed interpretation,
        bypassing the "delayed" quote-like operator.

           my $str = "String::Interpolate::Delayed"->new('$foo');

    "interpolated"
        Retrieve the text as a Perl scalar string, performing interpolation.

        The object overloads stringification to call this method. Passing a
        hashref as a parameter, allows you to define additional variables:

           my $str   = delayed "The $thing in $place @description.\n";
           my $thing = "rain";
   
           print $str->interpolated({
              place       => \"Spain",
              description => [qw/ stays mainly on the plain /],
           });

    "uninterpolated"
        Retrieve the text as a Perl scalar string, *without* performing
        interpolation.

    "ref"
        Just returns "undef". This is for the benefit of UNIVERSAL::ref.

CAVEATS
  Limitations on interpolation
    Most variables, including lexical variables and "magic" variables (such
    as $1, $_, etc) will work. There's one significant exception: @_. This
    limitation is inherited from "String::Interpolate".

  Danger, Will Robinson!!
    Interpolated Perl strings can execute arbitrary code:

       my $str = "I think I might @{[ unlink '/etc/passwd' ]}";

    This is a caveat with interpolated strings in Perl in general, however
    String::Interpolate::Delayed makes it easier to fall into this trap,
    because you might be tempted to load strings with delayed interpolation
    from an untrusted external source and throw them at the OO constructor.

  String::Interpolate
    This module includes a workaround for a bug in String::Interpolate. If
    the bug is fixed, the workaround may stop working. The workaround can be
    disabled by setting

       $String::Interpolate::Delayed::WORKAROUND = 0;

BUGS
  forkprove
    Test suite fails when run using App::ForkProve, but runs fine using
    App::Prove. I don't know what all that's about...

  Bug tracker
    Please report any other bugs to
    <http://rt.cpan.org/Dist/Display.html?Queue=String-Interpolate-Delayed>.

SEE ALSO
    String::Interpolate, PerlX::QuoteOperator.

AUTHOR
    Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE
    This software is copyright (c) 2013 by Toby Inkster.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.

DISCLAIMER OF WARRANTIES
    THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
    WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
    MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

