---
name: "Specio::Constraint::Structurable"
section: "3pm"
platform: "linux"
package: "perl-specio"
version: "0.53-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Specio::Constraint::Structurable"
---

# Specio::Constraint::Structurable(3pm)

A class which represents structurable constraints

## NAME

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

## VERSION

version 0.53

## 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\>.

## 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 - 2025 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.