NAME

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

VERSION

version v0.7.0

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

SOURCE

The development version is on github at https://github.com/robrwo/Hash-Match and may be cloned from git://github.com/robrwo/Hash-Match.git

BUGS

Please report any bugs or feature requests on the bugtracker website https://github.com/robrwo/Hash-Match/issues

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

AUTHOR

Robert Rothenberg <rrwo@cpan.org>

Some development of this module was based on work for Foxtons http://www.foxtons.co.uk.

CONTRIBUTOR

Mohammad S Anwar <mohammad.anwar@yahoo.com>

COPYRIGHT AND LICENSE

This software is Copyright (c) 2018 by Robert Rothenberg.

This is free software, licensed under:

  The Artistic License 2.0 (GPL Compatible)

cpanm Hash::Match

perl -MCPAN -e shell
install Hash::Match