---
name: "Type::Params::Signature"
section: "3pm"
platform: "linux"
package: "perl-type-tiny"
version: "2.010001-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Type::Params::Signature"
---

# Type::Params::Signature(3pm)

internal representation of a function signature

## NAME

Type::Params::Signature - internal representation of a function signature

## STATUS

This module is not covered by the Type-Tiny stability policy.

## DESCRIPTION

This is mostly internal code, but can be used to provide basic introspection for signatures.

### Constructors

- new(%attributes)

  - "new\_from\_compile($style, %attributes)"

  - new\_from\_v2api(\\%attributes)

  ### Attributes

All attributes are read-only.

- "package" **ClassName**

  The package we're providing a signature for. Will be used to look up any stringy type names.

- "subname" **Str**

  The sub we're providing a signature for.

- "description" **Str**

  - "method" **ArrayRef\[InstanceOf\['Type::Params::Parameter'\]\]**

  - "head" **ArrayRef\[InstanceOf\['Type::Params::Parameter'\]\]**

  - "tail" **ArrayRef\[InstanceOf\['Type::Params::Parameter'\]\]**

  - "parameters" **ArrayRef\[InstanceOf\['Type::Params::Parameter'\]\]**

  - "slurpy" **InstanceOf\['Type::Params::Parameter'\]**

  - "on\_die" **CodeRef**

  - "strictness" **Bool\|ScalarRef**

  - "next" **CodeRef**

  - "goto\_next" **CodeRef**

  Alias for `"next"`.

- "can\_shortcut" **Bool**

  Indicates whether the signature has no potential to alter `@_` allowing it to be returned without being copied if type checks pass. Generally speaking, you should not provide this to the constructor and rely on Type::Params::Signature to figure it out.

- "coderef" **InstanceOf\['Eval::TypeTiny::CodeAccumulator'\]**

  You probably don't want to provide this to the constructor. The whole point of this module is to build it for you!

*Attributes related to named parameters*

- "is\_named" **Bool**

  - "allow\_dash" **Bool**

  - "bless" **Bool\|ClassName**

  - "class" **ClassName**

  - "constructor" **Str**

  - "class\_attributes" **HashRef**

  HashRef suitable for passing to the `"import"` method of Class::XSAccessor. A default will be generated based on `"parameters"`

- "named\_to\_list" **ArrayRef**

  Can be coerced from a bool based on `"parameters"`.

- "list\_to\_named" **Bool**

  - "oo\_trace" **Bool**

  Defaults to true. Indicates whether blessed `$arg` hashrefs created by the signature will include a `'~~caller'` key.

*Bare attributes*

These attributes may be passed to the constructors and may do something, but no methods are provided to access the values later.

- "positional" or "pos" **ArrayRef**

  - "named" **ArrayRef**

  - "multiple" or "multi" **ArrayRef**

  - "returns" **Bool**

  Shortcut for setting `"returns_scalar"` and `"returns_list"` simultaneously.

- "want\_source" **Bool**

  - "want\_details" **Bool**

  - "want\_object" **Bool**

  - "rationalize\_slurpies" **Bool**

  ### Methods

*Predicates*

Predicate methods return true/false to indicate the presence or absence of attributes.

- "has\_description"

  - "has\_head"

  - "has\_tail"

  - "has\_parameters"

  - "has\_slurpy"

  - "has\_on\_die"

  - "has\_strictness"

  - "has\_returns\_scalar"

  - "has\_returns\_list"

  *Class making methods*

These methods will be called automatically during object construction and should not typically be called. They are public methods in case it is desired to subclass Type::Params::Signature.

- "make\_class\_pp"

  Builds the class specified in `"bless"` by evaluating Perl code.

- "make\_class\_xs"

  Builds the class specified in `"bless"` using Class::XSAccessor.

- "make\_class"

  Calls either `"make_class_pp"` or `"make_class_xs"`.

- "make\_class\_pp\_code"

  Generates the code for `"make_class_pp"`.

*Other methods*

- "BUILD"

  Called by the constructors. You should not call this.

- "return\_wanted"

  Normally returns the signature coderef, unless `"want_source"`, `"want_details"`, or `"want_object"` were provided to the constructor, in which case it will return the source code for the coderef, a hashref of details, or `$self`.

## ENVIRONMENT

- "PERL\_TYPE\_PARAMS\_XS"

  Affects the building of accessors for `$arg` objects. If set to true, will use Class::XSAccessor. If set to false, will use pure Perl. If this environment variable does not exist, will use Class::XSAccessor.

  If Class::XSAccessor is not installed or is too old, pure Perl will always be used as a fallback.

## BUGS

Please report any bugs to \<https://github.com/tobyink/p5-type-tiny/issues\>.

## SEE ALSO

Type::Params, Type::Params::Parameter, Type::Params::Alternatives.

## AUTHOR

Toby Inkster \<tobyink@cpan.org\>.

## COPYRIGHT AND LICENCE

This software is copyright (c) 2023-2025 by Toby Inkster.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

## DISCLAIMER OF WARRANTIES

THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.