[swift-evolution] Anoymous Enums (Updated)

[Shawn Erickson]

I have similar concerns as David. I do like the idea but I see it becoming
a problem in not a typical usage as David outlined. You likely would never
want to use this in any public API or possibly any function signature for
that matter (again given the limits implied by the short hand). I see it
being useful in a given scope of code for the purpose of readability and
even safety. It is when it starts to escape that scope it become less
useful and possibly unsafe.

On Mon, Feb 22, 2016 at 9:12 AM David Waite via swift-evolution <
swift-evolution at swift.org> wrote:

> Having this work similar to other anonymous types would be an extension to
> the proposal.
>
> Other anonymous types can be considered equivalent by their definitions,
> e.g. (x:Int, y:Int) taken as input from one function can be passed to
> another.
>
> E.g. your adjustTemperature function wanted to call a
> checkSafety(device:DeviceType, [low | medium | high]:temperature) -> Bool
> function - could it?
>
> what about if adjustTemperature took [low | medium | high | extreme]?
>
> what about adjustTemperature having an internal var lastAdjustment:[low |
> medium | high] - would that work?
>
> My concern is that there could many reasons to need to switch from
> shorthand/anonymous syntax to a full enum, and that switch will have the
> same fragility as changing a function from accepting a tuple to accepting a
> struct. If passing to another function or assigning to a variable would
> require a switch to a properly qualified enum, the feature seems not worth
> its character savings.
>
> And I’m already unsure it is worth its existing character savings,
> especially once you start documenting the meaning of low / medium / high
> for other developers, and especially if you now have to do so for multiple
> functions rather than a single enum declaration.
>
> -DW
>
> On Feb 22, 2016, at 9:46 AM, Erica Sadun via swift-evolution <
> swift-evolution at swift.org> wrote:
>
>
> On Feb 22, 2016, at 3:53 AM, Tino Heth via swift-evolution <
> swift-evolution at swift.org> wrote:
>
> I'm not sure wether I want to see that feature added, but I think there is
> a "structural" argument for it:
> We have anonymous functions (closures) and a (restricted) form of
> anonymous structs (tuples), so it would be consequent to have a anonymous
> variant for each fundamental entity in the language.
> I guess it is to late to establish a unified syntax for all of those,
> though…
>
>
> I like the symmetry with the other anonymous types. This provides a highly
> focused tweak to Swift, with limited impact, and a measurable benefit to
> developers. (AKA the "Rule of Lattner")
>
> Further, the values cannot be assigned to variables or passed as arguments
> as they have no "type".  I suspect it won't be hard to restrict them for
> being used with `Any` argument, limiting their use to flags and switch
> cases. If I'm conceptualizing this correctly, the benefits are clear and
> the consequences are small.
>
> -- Erica
>
> On Feb 21, 2016, at 11:52 PM, Yong hee Lee via swift-evolution <
> swift-evolution at swift.org> wrote:
>
>
> please check the link below.
>
> https://gist.github.com/erica/9148e2be916c7fae6f1e
>
>
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