Uninformative message on missing "in"

[maedoc]

with some code like

entry main (x:i32): f32 = 
  let f_ = map f (1..<x)
  let k_ = kura f_ 1f32 0.1f32

  reduce (+) 0.0f32 k_

where in is missing, the message is

Error at test.fut:16:1-1: unexpected end of file.

and then helpfully suggests filing an issue. I saw that in was missing but only because it was missing near the end of the file. I read that whitespace is ignored, but the compiler should know that there are only 3 arguments to kura so what sense would a call to reduce make after that?

Anyway, not a big deal, but since it suggested filing an issue, here we are

[athas]

The parser has almost no niceties in terms of good errors. Maybe it could be given some state so it can say what it's currently trying to parse, and what it's looking for... It's been a while since I looked at what our parser generator (Happy) can provide in this area, though.