Specio::Constraint::Structurable - A class which represents structurable
constraints
my $tuple = t('Tuple');
my $tuple_of_str_int = $tuple->parameterize( of => [ t('Str'), t('Int') ] );
This class implements the API for structurable types like
"Dict",
"Map"< and
"Tuple".
This class implements the same API as Specio::Constraint::Simple, with a few
additions.
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.
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.
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".
The source code repository for Specio can be found at
<https://github.com/houseabsolute/Specio>.
Dave Rolsky <autarch@urth.org>
This software is Copyright (c) 2012 - 2021 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.