Parentheses on left-hand side of curried call are optional

[bamarsha]

This PR makes the parentheses on the left-hand side of a curried call optional, so these are equivalent:

((Foo(x))(y))(z)
Foo(x)(y)(z)

[cgranade]

💕!!!

[msoeken]

Will this also work for UDT member access? For example:

let numbers = [Complex(1.0, 2.0), Complex(2.0, 3.0)];
let firstReal = Head(numbers)::Real;

[bamarsha]

No, both named and array items must use parentheses:

(Head(numbers))::Real
(Tail(numbers))[0]

[bettinaheim]

@msoeken The choice here is between supporting Adjoint opArray[i] or supporting Head(numbers)::Real since I think that both named item access and numbered item access should have the same precedence (hence we can support either one but not both).

[bamarsha]

@bettinaheim Would requiring parentheses in Adjoint (opArray[i]) be that bad? Is that more common than Head(numbers)::Real or Tail(numbers)[0]?

[msoeken]

Thanks for the additional info @smarsha and @bettinaheim. From my own experience, I tend to add parentheses around Adjoint op and forget them around variables before member or array access.

[bamarsha]

Merging this for now since I expect any future changes to the parser related to functors/item access will preserve the repeated call syntax without parentheses.