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Subject: Re: [PHP-DEV] Methods Overloading in PHP
From: rowan.collins@gmail.com (Rowan Tommins)


On 28 February 2021 13:20:57 GMT, Eugene Sidelnyk <zsidelnik@gmail.com> 
wrote:
>> It looks like your message is missing at least a link
>Sorry, I am using gmail and have attached an image which you probably
>can't
>see.
>
> https://habrastorage.org/webt/my/8t/in/my8tin97ukibw6ebh0cbaqhmv64.png


It's not to do with your mail client or formatting, the mailing list 
strips all attachments. Screenshots of text are probably the worst way 
of sharing a quote from something anyway.


I don't know what the rest of the article is like, but that quote makes 
a pretty poor case for overloading.

It has very little to do with OOP - SmallTalk, where OO was invented, 
doesn't have it, but plenty of non-OO languages do. There is some 
relationship to polymorphism, in that you can consider two classes with 
the same method name to be overloading that method name based on the 
type of "$this"; but in that case PHP does have it.

If anything, overloading on the types of multiple parameters is 
something I'd associate more with Functional Programming, where you 
might have multiple overloads for a global function like add(x, y), 
without them being "owned by" a particular type.

The example given of content(File) vs content(File, Charset) is also not 
great, because it can be achieved in any language with optional 
parameters, which does include PHP.  In some languages, using 
overloading would save an if check at run-time, because the compiler 
would select the correct overload, but PHP's method despatching and type 
checking are all done at run-time anyway.

With union types and named parameters, a lot of cases where overloading 
would be used in C# or Java can be expressed in a slightly different 
form in modern PHP. It would sometimes be nice to have multiple 
constructors, but named constructors are more flexible than overloading 
by type (e.g. Foo::fromName(string $name) and Foo::fromCode(string 
$code)), and static methods provide a reasonable stand-in for those.

Regards,
-- 
Rowan Tommins
[IMSoP]