NAME

Syntax::Keyword::Assert - assert keyword for Perl with zero runtime cost

SYNOPSIS

use Syntax::Keyword::Assert;

my $obj = bless {}, "Foo";
assert($obj isa "Bar");
# => Assertion failed (Foo=HASH(0x11e022818) isa "Bar")

DESCRIPTION

Syntax::Keyword::Assert provides a syntax extension for Perl that introduces a assert keyword.

By default assertions are enabled, but can be disabled by setting $ENV{PERL_ASSERT_ENABLED} to false before this module is loaded:

BEGIN { $ENV{PERL_ASSERT_ENABLED} = 0 }  # Disable assertions

When assertions are disabled, the assert are completely ignored at compile phase, resulting in zero runtime cost. This makes Syntax::Keyword::Assert ideal for use in production environments, as it does not introduce any performance penalties when assertions are not needed.

KEYWORDS

assert

assert(EXPR)

If EXPR is truthy in scalar context, then happens nothing. Otherwise, it dies with a user-friendly error message.

Here are some examples:

assert("apple" eq "banana");  # => Assertion failed ("apple" eq "banana")
assert(123 != 123);           # => Assertion failed (123 != 123)
assert(1 > 10);               # => Assertion failed (1 > 10)

SEE ALSO

• PerlX::Assert

  This module also uses keyword plugin, but it depends on Keyword::Simple. And this module's error message does not include the failed expression.

• Devel::Assert

  This module provides a similar functionality, but it dose not use a keyword plugin.

LICENSE

Copyright (C) kobaken.

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

AUTHOR

kobaken kentafly88@gmail.com