Template::Stash::Context(3)

NAME
Template::Stash::Context - Experimetal stash allowing list/scalar context definition

SYNOPSIS
    use Template;
    use Template::Stash::Context;

    my $stash = Template::Stash::Context->new(\%vars);
    my $tt2   = Template->new({ STASH => $stash });

DESCRIPTION
This is an alternate stash object which includes a patch from Craig Barratt to implement various new virtual methods to allow dotted template variable to denote if object methods and subroutines should be called in scalar or list context. It adds a little overhead to each stash call and I'm a little wary of applying that to the core default stash without investigating the effects first. So for now, it's implemented as a separate stash module which will allow us to test it out, benchmark it and switch it in or out as we require.

This is what Craig has to say about it:

Here's a better set of features for the core. Attached is a new version of Stash.pm (based on TT2.02) that:

* supports the special op "scalar" that forces scalar context on function calls, eg:

    cgi.param("foo").scalar

calls cgi.param("foo") in scalar context (unlike my wimpy scalar op from last night). Array context is the default.

With non-function operands, scalar behaves like the perl version (eg: no-op for scalar, size for arrays, etc).

* supports the special op "ref" that behaves like the perl ref. If applied to a function the function is not called. Eg:

    cgi.param("foo").ref

does *not* call cgi.param and evaluates to "CODE". Similarly, HASH.ref, ARRAY.ref return what you expect.

* adds a new scalar and list op called "array" that is a no-op for arrays and promotes scalars to one-element arrays.

* allows scalar ops to be applied to arrays and hashes in place, eg: ARRAY.repeat(3) repeats each element in place.

* allows list ops to be applied to scalars by promoting the scalars to one-element arrays (like an implicit "array"). So you can do things like SCALAR.size, SCALAR.join and get a useful result.

This also means you can now use x.0 to safely get the first element whether x is an array or scalar.

The new Stash.pm passes the TT2.02 test suite. But I haven't tested the new features very much. One nagging implementation problem is that the "scalar" and "ref" ops have higher precedence than user variable names.

AUTHOR
Andy Wardley <abw@wardley.org>

<http://wardley.org/>

VERSION
1.63, distributed as part of the Template Toolkit version 3.009, released on 30 March 2020.

COPYRIGHT
  Copyright (C) 1996-2007 Andy Wardley.  All Rights Reserved.

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

SEE ALSO
Template::Stash