Reason: Ternary formatting

[bordoley]

Assuming #1700 isn't implemented (I'm not against that change btw) can the formatting of ternaries be improved. For the common if/else formatting, it would preferable to follow facebook standard which is:

  ? trueResult
  : falseResult;

which is far more readable vs. the current formatting:

booleanCheck ?
  trueResult : falseResult;

For the nested ternaries, I'd love to see a JS style pattern match layout used, though I'm sure this is more contentious. For instance:

  ? trueResult1 :
booleanCheck2
  ? trueResult2 :
booleanCheck3
  ? trueResult3 :
fallbackResult;

[chenglou]

First one should be done. Not sure we should encourage the last one though. That should be pattern matching on a tuple

[bordoley]

Regarding the second pattern, I don't find myself using it in my reason/ocaml code, as pattern matching is so much more powerful. That said my major annoyance with prettier in the javascript world is it's formatting of ternaries. Perhaps non-nested formatting of these would be a decent incremental step when introducing people to reason. Or even better, maybe convert nested ternaries into switch statements.

[rickyvetter]

Pattern match on a tuple isn't lazy so it's not quite the same. I definitely think the simple case formatting is more important here.

[jordwalke]

Flattening out the formatting seems nice. I don't have strong opinions on the formatting style of ? placement (end of line or beginning). I suppose beginning of line would make it consistent with other operators.