NAME

Hash::Match - match contents of a hash against rules

SYNOPSIS

  use Hash::Match;

  my $m = Hash::Match->new( rules => { key => qr/ba/ } );

  $m->( { key => 'foo' } ); # returns false

  $m->( { key => 'bar' } ); # returns true

  $m->( { foo => 'bar' } ); # returns false

DESCRIPTION

This module allows you to specify complex matching rules for the contents of a hash.

METHODS

new

  my $m = Hash::Match->new( rules => $rules );

Returns a function that matches a hash reference against the $rules, e.g.

  if ( $m->( \%hash ) ) { ... }

Rules

The rules can be a hash or array reference of key-value pairs, e.g.

  {
    k_1 => 'string',    # k_1 eq 'string'
    k_2 => qr/xyz/,     # k_2 =~ qr/xyz/
    k_3 => sub { ... }, # k_3 exists and sub->($hash) is true
  }

For a hash reference, all keys in the rule must exist in the hash and match the criteria specified by the rules' values.

For an array reference, at least one key must exist and match the criteria specified in the rules.

Boolean Operators

The following special keys allow you to use nested boolean operators:

-not

  {
    -not => $subrules,
  }

Negate the $subrules.

If $subrules is a hash reference, that it is true when not all of the rules match.

If $subrules is an array reference, then it is true when none of the rules match.

-and

  [
    -and => \%subrules,
  ]

True if all of the %subrules are true.

You can also use

  {
    -and => \@subrules,
  }

which is useful for cases where the keys of @subrules are not strings, e.g. regular expressions.

-or

  {
    -or => \@subrules,
  }

True if at least one of the @subrules is true.

Regular Expressions for Keys

You can use regular expressions for matching keys. For example,

  -or => [
    qr/xyz/ => $rule,
  ]

will match if there is any key that matches the regular expression has a corresponding value which matches the $rule.

You can also use

  -and => [
    qr/xyz/ => $rule,
  ]

to match if all keys that match the regular expression have corresponding values which match the $rule.

AUTHOR

Robert Rothenberg, <rrwo at cpan.org>

LICENSE AND COPYRIGHT

Copyright 2014 Robert Rothenberg.

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

Any use, modification, and distribution of the Standard or Modified Versions is governed by this Artistic License. By using, modifying or distributing the Package, you accept this license. Do not use, modify, or distribute the Package, if you do not accept this license.

If your Modified Version has been derived from a Modified Version made by someone other than you, you are nevertheless required to ensure that your Modified Version complies with the requirements of this license.

This license does not grant you the right to use any trademark, service mark, tradename, or logo of the Copyright Holder.

This license includes the non-exclusive, worldwide, free-of-charge patent license to make, have made, use, offer to sell, sell, import and otherwise transfer the Package with respect to any patent claims licensable by the Copyright Holder that are necessarily infringed by the Package. If you institute patent litigation (including a cross-claim or counterclaim) against any party alleging that the Package constitutes direct or contributory patent infringement, then this Artistic License to you shall terminate on the date that such litigation is filed.

Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES. THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT PERMITTED BY YOUR LOCAL LAW. UNLESS REQUIRED BY LAW, NO COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

cpanm Hash::Match

perl -MCPAN -e shell
install Hash::Match