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Date: Thu, 26 Oct 2023 10:24:07 -0600
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Subject: Re: [PHP-DEV] Basic Type Alias
From: lanre@online-presence.ca (Lanre Waju)

I would like to voice my support for this and i'm willing to help with 
the implementation. As for differentiating between type aliases and 
classnames, only one of them can be instantiated.

Lanre

On 2023-10-26 12:37 a.m., Oladoyinbo Vincent wrote:
> 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?
>