Exhaustive match completion for tuples of enums

[spamegg1]

Is your feature request related to a problem? Please describe.

When I use tuples of enums, the exhaustive completion that is offered looks like case Tuple2(_1, _2) => .

Describe the solution you'd like

It would be nice if Metals can offer the "Cartesian product" of all the possible pairs. For example

enum Rotate:
  case L, R
enum Dir:
  case N, S, E, W

def spam(r: Rotate, d: Dir) = (r, d) match
  case (Rotate.L, Dir.N) => 
  // Metals completes all 8 possibilities in "match (exhaustive)"

Describe alternatives you've considered

n/a

Additional context

n/a

Search terms

enum match exhaustive completion

[spamegg1]

Just came to my mind... would it be possible to complete them with ??? on all the right sides (so it still compiles)? Just a little comfort / luxury thing.

[tgodzik]

It would be possible, we could even use the snippet syntax to be able to go over each ($1 $2 etc. will allow user to use tab to move to next), though not sure about the case where someone might want an empty case 🤔

It's worth experimenting, what will be most user friendly.