Swift style syntax

[Isiah Meadows]

Ok... I don't have a device to properly learn Swift with, as I don't own or
have easy access to a Mac.

On Tue, Oct 13, 2015, 13:48 Mohsen Azimi <me at azimi.me> wrote:

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> Isiah,
>
> In Swift it's not allowed to assign an operator so the ambiguous case you
> brought up can be avoided by not allowing assigning operators.
>
> ```
> let x = +; // not allowed
> ```
>
> Or it's not allowed to store operators in dictionaries:
>
> ```
>
> let dic = [
>   "add": +
> ];
>
> ```
> The only place (as far as I know) you can pass operators as functions is
> in arguments list of a function call. I don't know why but it doesn't work
> with unary operators either:
> ```
> let nums = [1,3,4];
>
>
> numsnums.map(++) // error
>
> ```
>
> On Tue, Oct 13, 2015 at 10:27 AM Isiah Meadows <isiahmeadows at gmail.com>
> wrote:
>
>> Steve, I have little problem with whatever ends up the case, as long as
>> it's shorter than `(x, y) => x + y`. The current idea was inspired by
>> Swift's `list.sort(>)` and `list.reduce(0, +)`.
>>
>> On Tue, Oct 13, 2015, 12:34 Steve Fink <sphink at gmail.com> wrote:
>>
>>> On 10/12/2015 11:06 PM, Isiah Meadows wrote:
>>> >
>>> > +1 for operators as functions (I frequently is them in languages that
>>> > have them), but there is an ambiguous case that frequently gets me:
>>> > does `(-)` represent subtraction or negation. It's usually the former
>>> > in languages with operators as functions.
>>> >
>>> > But here's a couple other potential syntactical ambiguities, dealing
>>> > with ASI:
>>> >
>>> > ```js
>>> > // Is this `x => f(x)` or `x = (>); f(x)`
>>> > x =>
>>> > f(x)
>>> >
>>> > // Is this `-x` or `-; x`?
>>> > -
>>> > x
>>> > ```
>>> >
>>> > Those can be addressed with a cover production to be used for
>>> > expression statements and direct value assignment, requiring
>>> > parentheses to clarify the latter case in each.
>>> >
>>> > A similar ambiguity problem, arguably harder to resolve, is partially
>>> > applied subtraction, such as `(- 2)`. Is that a -2 or is it equivalent
>>> > to `x => x - 2`? I will caution on this idea, as I know that's the
>>> > next logical step.
>>> >
>>>
>>> It it just me? I find all this talk of bare operators to be
>>> completely... uh, I'll go with "inadvisable".
>>>
>>> I can believe that you could carve out an unambiguous path through the
>>> grammar. But (a) it's going the way of line noise, (b) it uses up lots
>>> of possibilities for future expansion on something that isn't all that
>>> useful in the first place, and (c) it seems to be choosing concise
>>> syntax over readability in a big way.
>>>
>>> C++ has an 'operator' keyword (and even then it comes out pretty ugly --
>>> operator()(), anyone?) Perl6 has better syntax (syntax syntax?) for this:
>>>
>>>      infix:<+>
>>>      circumfix:«( )»
>>>
>>> or whatever. And of course Python uses double __underscores__ with ASCII
>>> operator names. All those are preferable to bare operators, to me.
>>>
>>>     -compose(+, *)(++x, +(3, 4), --y) - (3 + 4) - -(1, 2);
>>>
>>> I don't really *want* that to parse! At least make it
>>>
>>>    list.sort(#`>`);
>>>
>>> or something.
>>>
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>>>
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