Set and Range objects and literals

💡 Ideas
1

Expanding my comment from the chaining comparitor proposal...

Currently we write:

if (longVariableName == 'p' || longVariableName == 'div') {...}
if (effectiveMousePos.x <= right && effectiveMousePos.x >= left) {...}

and it's annoyingly verbose. Instead, I'd like to write:

if (longVariableName in {{p, div}}) {...}
if (effectiveMousePos.x in [<left, right>]) {...}

Sets are kind of like maps, so you can write (I have written)

if (longVariableName in {p:1, div:1}) {...}

but the irrelevant values are distracting, so it's awkward. Doubly so if there's a formatter or style rule that insists on thinking of the set as a map.

Literals and in tests are the case I most care about, but as long as we're doing this...

  • set[key] = True/False adds or removes a key from a set
  • sets take *, +, and - operators for intersection, union, and set-difference, with obvious *=, +=, and -=.
  • for (i in set) does this obvious
  • ranges have members start, end, min, and max. The first two are ordered based on definition, the latter based on comparison.
  • for (i of range) starts at min, then adds 1 until i exceeds max
  • for (i of range.by(step)) does the same except that it adds step each time. If step is negative, it starts from max.
2

It's probably not worth adding syntax for this.

For your first use case, ['p', 'div'].includes(longVariableName) already exists, is sufficient, and is plenty fast (you need a surprisingly amount of data before membership tests start being slower for arrays than for hashmaps, certainly more than it would be sensible to write inline).

1 Like
3

How would this syntax handle logic?

if( x > left && x < right ) ...
//vs.:
if( x > left || x < right ) ...
4

Try this:

//Yours
if (effectiveMousePos.x <= right && effectiveMousePos.x >= left) {...}

//Alternative (loose)
if ({with(effectiveMousePos) {x <= right && x>= left}}) {...}

//Alternative (strict)
if ((({x}) => (x <= right && x>= left))(effectiveMousePos)) {...}