Optional precondition after else and #else


(Amir Michail) #1

For example:

if a > 0 {
….
} else a < -5 {

}

This would be the same as:

if a > 0 {
….
} else {
  precondition(a < -5)

}


(Jordan Rose) #2

My first thought was that at first glance I'd get this confused with "else if". Obviously that doesn't change semantics in correct code, but it does seem a little subtle.

My second thought was "precondition or assert?" (i.e. "is the check enabled in release builds?") and that convinced me that this wasn't really worth the added complexity. It's a neat idea, but I think the language becomes more complex because of it without sufficient gain.

Jordan

···

On Dec 8, 2015, at 5:47, Amir Michail via swift-evolution <swift-evolution@swift.org> wrote:

For example:

if a > 0 {
….
} else a < -5 {

}

This would be the same as:

if a > 0 {
….
} else {
precondition(a < -5)

}

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(Adrian Kashivskyy) #3

How is this different from `else if`? :smile:

if a > 0 {
  ...
} else if a < -5 {
  ...
}

Pozdrawiam – Regards,
Adrian Kashivskyy

···

Wiadomość napisana przez Amir Michail via swift-evolution <swift-evolution@swift.org> w dniu 08.12.2015, o godz. 14:47:

For example:

if a > 0 {
….
} else a < -5 {

}

This would be the same as:

if a > 0 {
….
} else {
precondition(a < -5)

}


(Amir Michail) #4

My first thought was that at first glance I'd get this confused with "else if". Obviously that doesn't change semantics in correct code, but it does seem a little subtle.

My second thought was "precondition or assert?" (i.e. "is the check enabled in release builds?") and that convinced me that this wasn't really worth the added complexity. It's a neat idea, but I think the language becomes more complex because of it without sufficient gain.

I think “assert" should be removed from the language.

···

On Dec 8, 2015, at 6:34 PM, Jordan Rose <jordan_rose@apple.com> wrote:

Jordan

On Dec 8, 2015, at 5:47, Amir Michail via swift-evolution <swift-evolution@swift.org> wrote:

For example:

if a > 0 {
….
} else a < -5 {

}

This would be the same as:

if a > 0 {
….
} else {
precondition(a < -5)

}

_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution