NAME
Declare::Constraints::Simple::Library::General - General Constraints
SYNOPSIS
# custom error messages
my $constraint =
And( Message( 'You need to specify a Value', IsDefined ),
Message( 'The specified Value is not an Int', IsInt ));
# build results
my $valid = ReturnTrue;
my $invalid = ReturnFalse('Just because');DESCRIPTION
This library is meant to contain those constraints and constraint-like elements that apply generally to the whole framework.
CONSTRAINTS
Message($message, $constraint)
Overrides the message set on the result object for failures in $constraint. For example:
my $message = 'How hard is it to give me a number?';
my $constraint = Message($message, IsNumber);
my $result = $constraint->('duh...');
print $result->message, "\n";The Message constraint overrides the error message returned by it's whole subtree, however, the Message specification nearest to the point of failure will win. So while this
my $constraint = Message( 'Foo',
IsArrayRef( Message( 'Bar', IsInt )));
my $result = $constraint->(['I am not an Integer']);
print $result->message;will print Bar, this
my $result = $constraint->('I\'m not even an ArrayRef');
print $result->message;will output Foo.
Scope($name, $constraint)
Executes the passed $constraint in a newly generated scope named $name.
SetResult($scope, $name, $constraint)
Stores the result ov an evaluation of $constraint in $scope under $name.
IsValid($scope, $name)
Returns a true result if the result $name, which has to have been stored previously in the scope named $scope, was valid.
ReturnTrue()
Returns a true result.
ReturnFalse($msg)
Returns a false result containing $msg as error message.
SEE ALSO
Declare::Constraints::Simple, Declare::Constraints::Simple::Library
AUTHOR
Robert 'phaylon' Sedlacek <phaylon@dunkelheit.at>
LICENSE AND COPYRIGHT
This module is free software, you can redistribute it and/or modify it under the same terms as perl itself.