Lambda calculus in PureScript types

Check at the bottom of /test/Main.purs for examples.

Expressions

• String literals via symbols: Sym "example"
• String concatenation: Cat (Sym "Hello") (Sym "World")
• Boolean literals: Bool True/Bool False
• If expressions: If (Bool True) (Sym "X") (Sym "Y") to get Sym "X"
• Type literals: Typ Int, Typ (Maybe Int)
• Type constructor literals: Typ1 Maybe, Typ1 Array
• Functions via Lam :: * -> *:
  • Lam (Sym "example") is a function returning the symbol "example"
• Variables in binder counting form:
  • Var Here/V0
  • Var (There Here)/V1
  • ...
  • V5
• Application via App f x:
  • Type constructors: App (Typ1 Array) (Typ Int) to get Typ (Array Int)
  • Functions: App (Lam V0) (Sym "x") to get Sym "x"
• Empty record via EmptyRec
• Record cons via ConsRec k v r
• Record index via IndexRec k r

Values

• Functions
• Symbols
• Types
• Type constructors
• Booleans
• Records