Parsing updates for unicode

- Allow unicode characters in indents and operators
- Show lexing errors

newt/Combinatory.newt

@@ -0,0 +1,40 @@
+module Combinatory
+
+data Unit : U where
+  MkUnit : Unit
+
+infixr 7 _::_
+data List : U -> U where
+  Nil : {A : U} -> List A
+  _::_ : {A : U} -> A -> List A -> List A
+
+-- prj/menagerie/papers/combinatory
+
+infixr 6 _~>_
+data Type : U where
+  ι : Type
+  _~>_ : Type -> Type -> Type
+
+A : U
+A = Unit
+
+Val : Type -> U
+Val ι = A
+Val (x ~> y) = Val x -> Val y
+
+Ctx : U
+Ctx = List Type
+
+data Ref : Type -> Ctx -> U where
+  Z : {σ : Type} {Γ : Ctx} -> Ref σ (σ :: Γ)
+  S : {σ τ : Type} {Γ : Ctx} -> Ref σ Γ -> Ref σ (τ :: Γ)
+
+data Term : Ctx -> Type -> U where
+  App : {Γ : Ctx} {σ τ : Type} -> Term Γ (σ ~> τ) -> Term Γ σ -> Term Γ τ
+  Lam : {Γ : Ctx} {σ τ : Type} -> Term (σ :: Γ) τ -> Term Γ (σ ~> τ)
+  Var : {Γ : Ctx} {σ : Type} -> Ref σ Γ → Term Γ σ
+
+-- FIXME, I'm not getting an error for Nil, but it's shadowing Nil
+data Env : Ctx -> U where
+  ENil : Env Nil
+  ECons : {Γ : Ctx} {σ : Type} → Val σ → Env Γ → Env (σ :: Γ)

newt/Prelude.newt

@@ -17,6 +17,7 @@ data Either : U -> U -> U where
 
 infixr 0 _$_
 
+-- Currently very noisy in generated code
 _$_ : {a b : U} -> (a -> b) -> a -> b
 f $ a = f a