Move keyword arguments to the end and always use `;` before kwargs

[fredrikekre]

For example

 f(a; b) = a + b
-f(b = 2, 4)
-f(4, b = 2)
+f(4; b = 2)
+f(4; b = 2)

[fredrikekre]

Maybe also

-f(; a = a)
+f(; a)

[giordano]

Yes please 🤩

[giordano]

Maybe also

-f(; a = a)
+f(; a)

Maybe slightly convoluted, but I also like the automatic unpacking of fields in keyword arguments:

-f(; a = x.a)
+f(; x.a)

[gdalle]

Bumping this now that I use Runic on a daily basis, this is among my biggest pet peeves! It would be so lovely to avoid wondering about that bloody semicolon

[icweaver]

Same, this would be fantastic!

[fredrikekre]

One "showstopper" here is that rewriting f(a = g(), h()) to f(h(); a = g()) changes the evaluation order since Julia evaluates in source-order (order of g() and h() would swap). The good news is that having to reorder is very very rare: the 🤖 looked in 1000 Julia files, found ~3k calls with comma-kwargs but only one place where reordering was needed.

The safe implementation would be to just swap , to ; when allowed and never reorder arguments.

[fredrikekre]

Since reordering is very rare I think we can just skip it actually. See #231.