Calling a fun that doesn't exist returns `Not IO term`

[kings177]

When deploying this:

run {
  ask x = (Call 'a10000000000' []);
  (Done x)
}

it returns:

ERROR: 'FUN:a10000000000:91fd' is not an IO term

since "a10000000000" is not an existent fun, shouldn't it just return something like:

ERROR: Couldn't find 'FUN:a10000000000'

cc @steinerkelvin

[o-santi]

When I added this error check, there was really no way to no if a name had been defined before or not (maybe checking if arity was defined for it? this would be clumsy). As I am adding statement indexes, this becomes much easier to fix.

[steinerkelvin]

The problem here is actually that when Funs do not reduce they just stay stuck (exactly as in the original HVM). So we would need to (a) make this a runtime error, or (b) make an error specific on call (ugly).

(a) would be something like RuntimeError::FunDoesNotReduce { name, arg_prts: [...] }