> On 4 Apr 2016, at 15:49, Jeremy Pereira <[email protected]> > wrote: > >> On 3 Apr 2016, at 17:20, Haravikk via swift-evolution >> <[email protected]> wrote: >> >> Although I use trailing closures a lot less now, I think I’m a +1 anyway for >> consistency’s sake. >> >> I actually really like the idea of having trailing keywords in loops and if >> statements, these needn’t be required (except where a trailing closure is >> used) but for example it means I could do a fully natural language loop like: >> >> for eachValue in theValues do { … } > > This is actually kind of bizarre. Here we are trying to invent new syntax so > that the trailing closure can be used in if/while conditions and for > sequences. However, there is already a perfectly good syntax for putting > closures in these positions: put the closure in the parentheses of the > function call. Are people really so desperate to use trailing closures > everywhere that we have to add new keywords to the language? I don’t think > they are.
While I kind of agree (and personally prefer the use of parenthesis in most places anyway) it’s an inconsistency to be unable to use them I think. While It’s understandable from a parsing/ambiguity perspective, it’s not really intuitive. >> I like the consistency of every block having a kind of type (do, else, >> defer, catch etc.). > > That is a rabbit hole down which you probably shouldn't go. If we go down the > route of blocks having a “type”, the current situation in Swift becomes > somewhat inconsistent. I would argue that the `else` block on a `guard` is of > a different type to the `else` block on an `if`. If anything, the `else` > block of an `if` is closer to the `then` block. Also, would you allow the > `do` block in a `for` or `while` to have a `catch` block following it? If > not, then these blocks are different to the existing bare `do` block. Actually that’s not quite what I meant by “type”; while there is a case to be made for unifying these more (else and catch on loops for example) I just meant more along the lines that “do” would always group the main branch, “else” indicates an alternative path if a condition isn’t met and so-on. For the short term however this would just be a case of allowing do on the end to eliminate ambiguity and thus allow trailing closures, but in the long term it could be explored further. _______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
