Re: RFC - Immutable classes

I had a talk at Room11 and we discussed idea of mutator keyword. There were some concerns using mutator as a keyword - that's because immutable object is not being muted and also magically appeared $clone would be confusing. There's an idea of creating clone before function begins and operating simply on $this while it's newly created clone from immutable object instance and the additional keyword for such method would be for eg. transformer, so basically it may look like this: immutable class Money { public $amount = 0; public $currency; public function __construct($amount, $currency) { $this->amount = $amount; $this->currency = $currency; } public transformer function amount($newamount) { $this->amount = $newAmount; // $this actually is newly created clone return $this; } } $oneHundret = new Money(100, $eur); $twoHundret = $oneHundret->amount(200); How about that? 2016-09-05 4:21 GMT+02:00 Michał Brzuchalski <michal@brzuchalski.com>: > > > 2016-09-04 22:38 GMT+02:00 Fleshgrinder <php@fleshgrinder.com>: > >> On 9/4/2016 2:29 PM, Michał Brzuchalski wrote: >> >> Providing mutator | >> >> mut keyword as method modifier sounds liek a >> good >> >> idea, >> >> althought passing $clone parameter as first >> >> additional param could >> break >> >> method declaration and would be misleading. >> >> >> >> Assuming mutator method is designed to return mutated clone of >> immutable >> >> object >> >> having $clone variable could be handled internally >> >> without breaking >> >> method declaration. >> >> >> >> Such variable could be unlocked while in mutator method and locked on >> >> return. >> >> I was thinking about additional check if such mutator returns >> >> $clone >> but >> >> not $this >> >> but I don't see the need of it - assuming there is no what to change in >> >> some >> >> circumstances ther would be also possible to return >> >> $this. >> >> >> >> The return type declaration self could increase >> >> readability, but >> should >> >> not be required, >> >> as some developers doesn't already use return types. >> >> >> > >> > It could look like in this gist >> > >> > https://gist.github.com/brzuchal/e7b721e22a19cca42ec0d1f597a23baf >> > >> >> This is exactly how I meant it, yes. I actually prefer it if the >> variable just exist in the context instead of passing it as first >> argument. It's less obvious that it exists but the same could be said >> about $this. >> >> Would it be possible to have this thing just in time instead of >> automatically created in every mutator function? >> >> public mutator function f() { >> if (condition) { >> $clone is created; >> return $clone; >> } >> return $this; >> } >> >> PS: I started overhauling the test cases and error messages and will >> create a PR against your branch soon. I will start with the RFC >> afterwards. Should I simply edit the RFC in the Wiki or should we manage >> this somewhere else? >> >> > You may begin with modifications on RFC eg. in a gist so we can all discuss > about it before putting on RFC, is that okay to you? > > >> -- >> Richard "Fleshgrinder" Fussenegger >> >> > > > -- > regards / pozdrawiam, > -- > Michał Brzuchalski > brzuchalski.com > -- regards / pozdrawiam, -- Michał Brzuchalski brzuchalski.com