[ghc-steering-committee] Proposal #173: The dot type operator, rec: accept

[Eric Seidel]

Hello,

This proposal would extend the parser to allow the '.' character to appear in type operators, allowing one to write code like the following:

```
type (f . g) x = f (g x)

foo :: (Maybe . Either Int) Bool
foo = Just (Right True)
```

I recommend we accept the proposal, as it would resolve an odd inconsistency between the term and type languages. The main downside seems to be that combining a type-level '.' with a 'forall' is a bit hard to read, but I think the benefits of a more consistent syntax outweigh this concern.

Eric