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(EXPR)

    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>