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https://github.com/kfly8/p5-function-interface
Declare typed interface package
https://github.com/kfly8/p5-function-interface
perl perl5 perl5-module
Last synced: 2 days ago
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Declare typed interface package
- Host: GitHub
- URL: https://github.com/kfly8/p5-function-interface
- Owner: kfly8
- License: other
- Created: 2019-02-24T05:23:00.000Z (over 5 years ago)
- Default Branch: main
- Last Pushed: 2022-06-13T10:46:39.000Z (over 2 years ago)
- Last Synced: 2024-09-24T19:50:20.853Z (2 days ago)
- Topics: perl, perl5, perl5-module
- Language: Perl
- Homepage:
- Size: 75.2 KB
- Stars: 8
- Watchers: 3
- Forks: 1
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- Changelog: Changes
- License: LICENSE
Awesome Lists containing this project
README
[](https://travis-ci.org/kfly8/p5-Function-Interface) [](https://coveralls.io/r/kfly8/p5-Function-Interface?branch=master) [](https://metacpan.org/release/Function-Interface)
# NAME
Function::Interface - declare typed interface package
# SYNOPSIS
Declare typed interface package `IFoo`:
```perl
package IFoo {
use Function::Interface;
use Types::Standard -types;
fun hello(Str $msg) :Return(Str);
fun add(Int $a, Int $b) :Return(Int);
}
```
Implements the interface package `IFoo`:
```perl
package Foo {
use Function::Interface::Impl qw(IFoo);
use Types::Standard -types;
fun hello(Str $msg) :Return(Str) {
return "HELLO $msg";
}
fun add(Int $a, Int $b) :Return(Int) {
return $a + $b;
}
}
```
Use the type `ImplOf`:
```perl
package FooService {
use Function::Interface::Types qw(ImplOf);
use Function::Parameters;
use Function::Return;
use Mouse;
use aliased 'IFoo';
fun greet(ImplOf[IFoo] $foo) :Return() {
print $foo->hello;
return;
}
}
my $foo_service = FooService->new;
my $foo = Foo->new; # implements of IFoo
$foo_service->greet($foo);
```
# DESCRIPTION
This module provides a typed interface.
`Function::Interface` declares abstract functions without implementation and defines an interface package.
`Function::Interface::Impl` checks if the abstract functions are implemented at **compile time**.
## SUPPORT
This module supports all perl versions starting from v5.14.
## Declare function
`Function::Interface` provides two new keywords, `fun` and `method`, for declaring abstract functions and methods with types:
```
fun hello(Str $msg) :Return(Str);
method new(Num :$x, Num :$y) :Return(Point);
```
The method of declaring abstract functions is the same as [Function::Parameters](https://metacpan.org/pod/Function::Parameters) and [Function::Return](https://metacpan.org/pod/Function::Return).
### declare parameters
Function arguments must always specify a variable name and type constraint, and named arguments and optional arguments can optionally be specified:
```perl
# positional parameters
# e.g. called `foo(1,2,3)`
fun foo1(Int $a, Int $b, Int $c) :Return();
# named parameters
# e.g. called `bar(x => 123, y => 456)`
fun foo2(Num :$x, Num :$y) :Return();
# optional
# e.g. called `baz()` or `baz('some')`
fun foo3(Str $msg=) :Return();
```
### declare return types
Specify zero or more type constraints for the function's return value:
```
# zero(empty)
fun bar1() :Return();
# one
fun bar2() :Return(Str);
# two
fun bar3() :Return(Str, Num);
```
## requirements of type constraint
The requirements of type constraint of `Function::Interface` is the same as for [Function::Parameters](https://metacpan.org/pod/Function::Parameters) and [Function::Return](https://metacpan.org/pod/Function::Return).
# METHODS
## Function::Interface::info($interface\_package)
The function `Function::Interface::info` lets you introspect interface functions:
```perl
# declare interface package
package IBar {
use Function::Interface;
fun hello() :Return();
fun world() :Return();
}
# introspect
my $info = Function::Interface::info 'IBar';
$info->package; # => IBar
$info->functions; # => list of Function::Interface::Info::Function
```
It returns either `undef` if it knows nothing about the interface or an object of [Function::Interface::Info](https://metacpan.org/pod/Function::Interface::Info).
# SEE ALSO
[Function::Interface::Impl](https://metacpan.org/pod/Function::Interface::Impl)
# LICENSE
Copyright (C) kfly8.
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
# AUTHOR
kfly8