lambda-cube-0.3.0.0: src/LambdaCube/SystemF/Normalizer.hs

module LambdaCube.SystemF.Normalizer where

import           LambdaCube.SystemF.Ast
import           LambdaCube.SystemF.Substitution

normalize :: LCTerm -> LCNormalTerm
normalize = go
  where
    go (LCVar x) = LCNormNeut $ LCNeutVar x
    go (LCLam t b) = LCNormLam t $ go b
    go (LCTLam b) = LCNormTLam $ go b
    go (LCApp f a) =
      case go f of
        LCNormLam _ b -> substituteNormalInNormal a' 0 b
        LCNormTLam _  -> error "Did you really type check this?"
        LCNormNeut nt -> LCNormNeut $ nt `LCNeutApp` a'
      where
        a' = go a
    go (LCTApp f t) =
      case go f of
        LCNormLam _ _ -> error "Did you really type check this?"
        LCNormTLam b  -> substituteTypeInNormal t 0 b
        LCNormNeut nt -> LCNormNeut $ nt `LCNeutTApp` t