Syntax::Keyword::Assert(3pm)

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>