Problems with assignments as expressions #225

Similar to #221, evaluating assignments as expression has some issues.

Example:

declare function a(): number[];
declare function b(): number;
declare function c(): number;
declare const d: number[];
let e = ( a()[b()] = c() );

Currently produces:

local e = ((function() a()[(b())+1] = c(); return a()[(b())+1] end)());

The problem here being that a and b are called twice having potentially undesired effects.

A solution could be to cache with a temp:

local e = ((function() local __temp = c(); a()[(b())+1] = __temp; return __temp end)());

But there's a subtle problem with this. Now, c is called before a and b. This would cause issues if c depends on a or b. shudder

The only way I can think of to execute it all correctly would be to use another lambda:

local e = ((function() local __temp; a()[(b())+1] = (function() __temp = c(); return __temp end)(); return __temp end)());

At this point things should work correctly but it's very ugly and not great performance-wise.