ENIGMA Development Environment

I doubt anyone would disagree that ENIGMA needs arrays. What I'm proposing is that rather than inherit array syntax from C++, we take a page out of the JavaScript playbook and denote them with [].

I want to use [] for a couple reasons. First, of course, is that [1, 2, 3][1] looks neater than {1,2,3}[1]. That was a joke; I don't give a shit about that. What I want to allow is this sort of syntax:

[x, y] = [y, x] // Switches the values of x and y
[x, y] = get_some_coordinates(); // Fetches a length-2 array of coordinates, assign

Using {} for arrays, {x,y} would be ambiguous; it could be a new scope which uses x and y, or it could be our assignment array. There would be next to no way to distinguish the two, so it's out of the question if we want the assignment array.

As for the dynamics, when compiling to C, this is what it would look like:
In the [a,b,c]=array_func() case:
{
  Array tmp = array_func(); // This is copied verbatim
  switch (tmp.length) { default: // Array size is size_t; must be >= 0
    case 3: c = tmp[3]; // Waterfall
    case 2: b = tmp[2];
    case 1: a = tmp[1];
    case 0: ;
  }
}

In the [a,b,c] = scalar_func() special case:
  c = b = a = scalar_func();

As for building an array, that's easy. Old ENIGMA can do that. [expression1, expression2, expression3] simply becomes this:
[snip=cpp](Array(3).put(0,expression1).put(1,expression2).put(2,expression3))[/snip]

Where [snip]Array(int N)[/snip] reserves N variants, and [snip]Array& Array::put(int, variant)[/snip] is the same as [snip]Array::operator[](int)::operator=(variant)[/snip].

This is an EDL feature; the expectation is that the user will distinguish those two with the use of a semicolon. However, if you have an idea to eliminate that, let's hear it.

What would you have [] = scalar do?

This is also cool, but what if I only want to set one of the variables? Like have:
[0, y] = get_some_coordinates();That wouldn't work would it?

So would there be a possibility to return only N'th result? From your previous example I see that this would probably work:
[x] = get_some_coordinates();As that would just return the first variable to x, but if I wanted the second one?

y = get_some_coordinates()[2]Also works. I just didn't think of that for some reason (though I do it all the time in C++ with OpenCV).

I don't want to use ?, since ? is ternary. [snip=EDL](boolean_expression ? x : y) = 10;[/snip] is already valid EDL. It will remain so in the arrays, I imagine. I do like your [snip]...[/snip] to denote that the array may be larger. However, I like HaRRi's 0 idea better than __unused.

Perhaps as a prefix, ? could denote optionality.
[snip=EDL][0, x, y, ?z] = get_wxyz();[/snip]

I was just going on about how that'd be fine. All I really need is to make sure JDI includes the & in variable types it coerces, then I can ask JDI for the type of ENIGMA's AST.