Eval::TypeTiny - utility to evaluate a string of Perl code in a clean environment
This module is considered part of Type-Tiny's internals. It is not
covered by the
Type-Tiny stability policy.
This module is used by Type::Tiny to compile coderefs from strings of
Perl code, and hashrefs of variables to close over.
This module exports one function, which works much like the similarly named
function from the Eval::Closure manpage:
- eval_closure(source => $source, environment => \%env, %opt)
-
The following constants may be exported, but are not by default.
- HAS_LEXICAL_SUBS
-
Boolean indicating whether Eval::TypeTiny has support for lexical subs.
(This feature requires Perl 5.18.)
- ALIAS_IMPLEMENTATION
-
Returns a string indicating what implementation of
alias => 1 is
being used. Eval::TypeTiny will automatically choose the best implementation.
This constant can be matched against the IMPLEMENTAION_* constants.
- IMPLEMENTATION_NATIVE
-
If
ALIAS_IMPLEMENTATION eq IMPLEMENTATION_NATIVE then Eval::TypeTiny is
currently using Perl 5.22's native alias feature. This requires Perl 5.22.
- IMPLEMENTATION_DEVEL_LEXALIAS
-
If
ALIAS_IMPLEMENTATION eq IMPLEMENTATION_DEVEL_LEXALIAS then
Eval::TypeTiny is currently using the Devel::LexAlias manpage to provide aliases.
- IMPLEMENTATION_PADWALKER
-
If
ALIAS_IMPLEMENTATION eq IMPLEMENTATION_PADWALKER then
Eval::TypeTiny is currently using PadWalker to provide aliases.
- IMPLEMENTATION_TIE
-
If
ALIAS_IMPLEMENTATION eq IMPLEMENTATION_TIE then Eval::TypeTiny is
using the fallback implementation of aliases using tie. This is the
slowest implementation, and may cause problems in certain edge cases, like
trying to alias already-tied variables, but it's the only way to implement
alias => 1 without a recent version of Perl or one of the two optional
modules mentioned above.
The evaluation is performed in the presence of strict, but the absence of
warnings. (This is different to the Eval::Closure manpage which enables warnings for
compiled closures.)
The feature pragma is not active in the evaluation environment, so the
following will not work:
use feature qw(say);
use Eval::TypeTiny qw(eval_closure);
my $say_all = eval_closure(
source => 'sub { say for @_ }',
);
$say_all->("Hello", "World");
The feature pragma does not ``carry over'' into the stringy eval. It is
of course possible to import pragmas into the evaluated string as part of the
string itself:
use Eval::TypeTiny qw(eval_closure);
my $say_all = eval_closure(
source => 'sub { use feature qw(say); say for @_ }',
);
$say_all->("Hello", "World");
Please report any bugs to
http://rt.cpan.org/Dist/Display.html.
the Eval::Closure manpage, the Error::TypeTiny::Compilation manpage.
Toby Inkster <tobyink@cpan.org>.
This software is copyright (c) 2013-2014, 2017-2019 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.
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.
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