Declare::Constraints::Simple::Library::Operators - Operators
# all hast to be valid my $and_constraint = And( IsInt, Matches(qr/0$/) ); # at least one has to be valid my $or_constraint = Or( IsInt, HasLength ); # only one can be valid my $xor_constraint = XOr( IsClass, IsObject ); # reverse validity my $not_an_integer = Not( IsInt ); # case valid, validate 'bar' key depending on 'foo' keys value my $struct_prof = And( IsHashRef, CaseValid( OnHashKeys(foo => IsEq("FooArray")), OnHashKeys(bar => IsArrayRef), OnHashKeys(foo => IsEq("FooHash")), OnHashKeys(bar => IsHashRef) ));
This module contains the frameworks operators. These constraint like elements act on the validity of passed constraints.
Is true if all passed
@constraints are true on the value. Returns the result of the first failing constraint.
Is true if at least one of the passed
@contraints is true. Returns the last failing constraint's result if false.
Valid only if a single one of the passed
@constraints is valid. Returns the last failing constraint's result if false.
This is valid if the passed
$constraint is false. The main purpose of this operator is to allow the easy reversion of a constraint's trueness.
This runs every given
$test argument on the value, until it finds one that returns true. If none is found, false is returned. On a true result, howver, the corresponding
$conseq constraint is applied to the value and it's result returned. This allows validation depending on other properties of the value:
my $flexible = CaseValid( IsArrayRef, And( HasArraySize(1,5), OnArrayElements(0 => IsInt) ), IsHashRef, And( HasHashElements(qw( head tail )), OnHashKeys(head => IsInt) ));
Of course, you could model most of it probably with the other operators, but this is a bit more readable. For default cases use
ReturnTrue from Declare::Constraints::Simple::Library::General as test.
Robert 'phaylon' Sedlacek
This module is free software, you can redistribute it and/or modify it under the same terms as perl itself.