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

  my $n = Hash::Match->new( rules => {
     -any => [ key => qr/ba/,
               key => qr/fo/,
             ],
  } )

  $n->( { key => 'foo' } ); # returns true

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->{k_3}) 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, some (any) key must exist and match the criteria specified in the rules.

You can specify more complex rules using special key names:

-all

  {
    -all => $rules,
  }

All of the $rules must match, where $rules is an array or hash reference.

-any

  {
    -any => $rules,
  }

Any of the $rules must match.

-notall

  {
    -notall => $rules,
  }

Not all of the $rules can match (i.e., at least one rule must fail).

-notany

  {
    -any => $rules,
  }

None of the $rules can match.

-and

This is a (deprecated) synonym for -all.

-or

This is a (deprecated) synonym for -any.

-not

This is a (deprecated) synonym for -notall and -notany, depending on the context.

Note that rules can be specified arbitrarily deep, e.g.

  {
    -any => [
       -all => { ... },
       -all => { ... },
    ],
  }

or

  {
    -all => [
       -any => [ ... ],
       -any => [ ... ],
    ],
  }

The values for special keys can be either a hash or array reference. But note that hash references only allow strings as keys, and that keys must be unique.

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

  -any => [
    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

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

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

You can also use functions to match keys. For example,

  -any => [
    sub { $_[0] > 10 } => $rule,
  ]

SEE ALSO

The following modules have similar functionality:

Data::Match

Data::Search

AUTHOR

Robert Rothenberg, <rrwo at cpan.org>

Contributors

Mohammad S Anwar

ACKNOWLEDGEMENTS

Foxtons, Ltd.

LICENSE AND COPYRIGHT

Copyright 2017 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