NAME

Specio::Constraint::Structurable - A class which represents structurable constraints

VERSION

version 0.40

SYNOPSIS

    my $tuple = t('Tuple');
    
    my $tuple_of_str_int = $tuple->parameterize( of => [ t('Str'), t('Int') ] );

DESCRIPTION

This class implements the API for structurable types like Dict, Map< and Tuple.

API

This class implements the same API as Specio::Constraint::Simple, with a few additions.

Specio::Constraint::Structurable->new(...)

This class's constructor accepts two additional parameters:

  • parameterization_args_builder

    This is a subroutine that takes the values passed to of and returns a hash of named arguments. These arguments will then be passed into the structured_constraint_generator or structured_inline_generator.

    This should also do argument checking to make sure that the argument passed are valid. For example, the Tuple type turns the arrayref passed to of into a hash, along the way checking that the caller did not do things like interleave optional and required elements or mix optional and slurpy together in the definition.

    This parameter is required.

  • name_builder

    This is a subroutine that is called to generate a name for the structured type when it is created. This will be called as a method on the Specio::Constraint::Structurable object. It will be passed the hash of arguments returned by the parameterization_args_builder.

    This parameter is required.

  • structured_constraint_generator

    This is a subroutine that generates a new constraint subroutine when the type is structured.

    It will be called as a method on the type and will be passed the hash of arguments returned by the parameterization_args_builder.

    This parameter is mutually exclusive with the structured_inline_generator parameter.

    This parameter or the structured_inline_generator parameter is required.

  • structured_inline_generator

    This is a subroutine that generates a new inline generator subroutine when the type is structured.

    It will be called as a method on the Specio::Constraint::Structured object when that object needs to generate an inline constraint. It will receive the type parameter as the first argument and the variable name as a string as the second.

    The remaining arguments will be the parameter hash returned by the parameterization_args_builder.

    This probably seems fairly confusing, so looking at the examples in the Specio::Library::Structured::* code may be helpful.

    This parameter is mutually exclusive with the structured_constraint_generator parameter.

    This parameter or the structured_constraint_generator parameter is required.

$type->parameterize(...)

This method takes two arguments. The of argument should be an object which does the Specio::Constraint::Role::Interface role, and is required.

The other argument, declared_at, is optional. If it is not given, then a new Specio::DeclaredAt object is creating using a call stack depth of 1.

This method returns a new Specio::Constraint::Structured object.

SUPPORT

Bugs may be submitted at https://github.com/houseabsolute/Specio/issues.

I am also usually active on IRC as 'autarch' on irc://irc.perl.org.

SOURCE

The source code repository for Specio can be found at https://github.com/houseabsolute/Specio.

AUTHOR

Dave Rolsky <autarch@urth.org>

COPYRIGHT AND LICENSE

This software is Copyright (c) 2012 - 2017 by Dave Rolsky.

This is free software, licensed under:

  The Artistic License 2.0 (GPL Compatible)

The full text of the license can be found in the LICENSE file included with this distribution.