@John McCall The expense at runtime issue of course. The fact that I need to add one more line would never bother me enough to bother a few hundreds ppl in turn :).
On Tue, Jan 31, 2017 at 9:51 PM, John McCall <[email protected]> wrote: > On Jan 28, 2017, at 1:07 PM, Victor Petrescu via swift-evolution < > [email protected]> wrote: > Hello, > > My name is Victor, been a developer (C, delphi, php, java, js) for the > last 10 years or so and lately I had the chance to try swift. I have a > suggestion/question regarding initializers. > > Sidenote: If this is not the correct mailing list for this can you please > redirect me to the right place? > > Consider the following 2 classes and code: > > class A { > var x:Int > > init() { > x = 1 > } > } > > class B : A { > override init() { > super.init() // Swift FORCES this call > x = 2 > } > } > > var a:B > for i in 0...99999999 { > a = B() // Whatever... some code that inits B. > } > > This results in 99999999 x = 1 then 99999999 x = 2... the x = 1 being > totally useless in this particular case. > > In this case, if you don't make the super init you get a compile error. > > > > *Now... I see the use of this. It ensure that all members are initialized. > For example if A had a private variable (another strange choice here with > what private means in swift but I haven't thought on it yet so... maybe is > a cool choice), the B init could not initialize it. I also understand that > the cases when you need this minor performance gain are rather rare (but > they do still exist). So I guess the choice for the super.init() had that > reasoning.* > > Still... my suggestion would be to give a warning, maybe force a key word > before the init (like iKnowWhatImDoing init() {}), THEN in case vars are > still not inited give a runtime error (afaik Objective C for example gives > a warning). That ensures everything is ok and also allows programmers that > have strange cases to treat them accordingly. > > Anyway... that would be my suggestion. Maybe this was discussed before > also... If this was discussed before can you please point me to the > discussion? I like to understand the choices for the tools I use. > > > What problem are you trying to solve here? Are you annoyed at having to > write super.init() and/or initialize your instance variables instead of > having the compiler "do the right thing" automatically, or are you worried > that calling super.init() will be a small but unnecessary expense at > runtime? Because these seem like completely different problems that should > be addressed in completely different ways. > > John. > > > > P.S. Please excuse any grammatical errors... English is not my first > language. > > Thank you for your time and have a great day, > Petrescu Victor > _______________________________________________ > swift-evolution mailing list > [email protected] > https://lists.swift.org/mailman/listinfo/swift-evolution > > >
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