[swift-evolution] [Proposal] Rename fatalError() API

[D. Felipe Torres]

*Introduction*

This function was introduced along others to halt execution of the running
instance to convey a state of affairs without resolution whatsoever. This
proposal lays the case that this function is not performing its stated
mission and attempts to help it come forward with its real intentions in
order  to have a better conformance with the Swift naming guidelines.

*Motivation*

The main motivation to this proposal is to act as a catalyst for the
community to acknowledge the identity of this function and stay true to the
values bestowed upon us by Chris Lattner and his disciples, the Core Team.

As evidenced in a quick search over a the great repository of Gitxandria
<https://github.com/search?l=Swift&q=fatalError%28%29&type=Code&utf8=✓> we
are witness to several examples of the true calling of fatalError(). A few
examples are cited below for those who receive this letter in print.

//Example 1

switch result {

case .Success(let response):

    print("Today's horoscope is: \(response)")

    break

case .Failure(let error):

    fatalError("Present \(error) to user")

}


//Example 2

func cell(at index: Int) -> Cell {

    if (0..<10).contains(index) {

        return Cell(horses[index])

    }

    if (10..<20).contains(index) {

        return Cell(ponies[index])

    }



    fatalError("Unicorns go here")

}


As seen in the previous examples, the calling of fatalError is seldom that.


 *Proposed solution*


The proposed solution is to rename `fatalError(_ message: String)` to
`willItToCompile(finishLater: String)` to convey the right terminology for
it's calling. Here are the revised examples:


//Example 1

switch result {

case .Success(let response):

    print("Today's horoscope is: \(response)")

    break

case .Failure(let error):

    willItToCompile(finishLater: "Present \(error) to user")

}


//Example 2

func cell(at index: Int) -> Cell {

    if (0..<10).contains(index) {

        return Cell(horses[index])

    }

    if (10..<20).contains(index) {

        return Cell(ponies[index])

    }



    willItToCompile(finishLater: "Unicorns go here")

}


As you can see, the intent of this code is clearer and the true meaning of
the developer is revealed.


 *Source Compatibility*


This is an important issue, we must stand to this shameful tradition and
break it. Functions deserve to be called by their purest and true identity,
we are still within the window of source breaking changes so there is no
better time, the time is now!


*Alternatives considered*


Keep calling it the same shameful name to an innocent function who has done
nothing but bring us joy to our development cycles and help us throughout
hard times.



------

Merry Christmas and

Happy New Year
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20170106/d7b3e1b2/attachment.html>