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Date: Thu, 26 Oct 2023 07:37:09 +0100
Message-ID: <CAHXoPRtjsPzgpYnhB05hjdZo6Q-MDr4TUGbn9LQ77-hKVTCZOA@mail.gmail.com>
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Subject: Basic Type Alias
From: oladoyinbov@gmail.com (Oladoyinbo Vincent)

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Greetings to you all,

I will like to submit an RFC on introducing type alias to php.

Even though Generics won't or never be introduced to PHP, personally i will
like php to add the type alias feature.

Type aliases provide a mechanism to create more descriptive and readable
type hints in PHP code. This enhancement will improve code readability and
maintainability and also to promote type reusability.


Motivation:

The motivation behind introducing type aliases is to:

1. Enhance code readability by allowing developers to use meaningful type
hint names.
2. Improve code maintainability by reducing the likelihood of type hint
updates throughout the codebase.
3. Encourage the adoption of best practices for type hinting.


Proposal:

Syntax:

Type aliases will be declared using the `type` or `typealias` keyword,
followed by the alias name, an equal sign (`=`), and the type it is aliased
to.


Sample:

```
type MyType = string;

// or

typealias MyType = string;


// Advance

type MyType = string|null;

// or

type MyType = [string, null];

```


Usage:

Type aliases can be used in parameter and return type hints as follows:

```

function greetings(MyType $message): string {

    // Implementation

}

greetings(1); // TypeError

```

Since this is just a basic feature, Type aliases Inheritance (compound
type) may not be added, since we are not digging deeper into generics :).



References:

https://docs.python.org/3/glossary.html#term-type-alias

https://doc.rust-lang.org/beta/reference/items/type-aliases.html

https://www.typescriptlang.org/docs/handbook/typescript-in-5-minutes-func.html#type-aliases


So, What do you think?

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