churf/tests/Tests.hs
2023-02-28 17:15:48 +01:00

94 lines
4 KiB
Haskell

{-# LANGUAGE OverloadedStrings #-}
{-# OPTIONS_GHC -Wno-unrecognised-pragmas #-}
{-# HLINT ignore "Use <$>" #-}
{-# HLINT ignore "Use camelCase" #-}
module Main where
import Data.Either (isLeft, isRight)
import Data.Map (Map)
import qualified Data.Map as M
import Grammar.Abs
import Test.Hspec
import Test.QuickCheck
import TypeChecker.TypeChecker
import qualified TypeChecker.TypeCheckerIr as T
import TypeChecker.TypeCheckerIr (Ctx (..), Env (..), Error, Infer,
Poly (..))
main :: IO ()
main = hspec $ do
infer_elit
infer_eann
infer_eid
infer_eabs
infer_eapp
infer_elit = describe "algoW used on ELit" $ do
it "infers the type mono Int" $ do
getType (ELit (LInt 0)) `shouldBe` Right (TMono "Int")
it "infers the type mono Int" $ do
getType (ELit (LInt 9999)) `shouldBe` Right (TMono "Int")
infer_eann = describe "algoW used on EAnn" $ do
it "infers the type and checks if the annotated type matches" $ do
getType (EAnn (ELit $ LInt 0) (TMono "Int")) `shouldBe` Right (TMono "Int")
it "fails if the annotated type does not match with the inferred type" $ do
getType (EAnn (ELit $ LInt 0) (TPol "a")) `shouldSatisfy` isLeft
it "should be possible to annotate with a more specific type" $ do
let annotated_lambda = EAnn (EAbs "x" (EId "x")) (TArr (TMono "Int") (TMono "Int"))
in getType annotated_lambda `shouldBe` Right (TArr (TMono "Int") (TMono "Int"))
it "should fail if the annotated type is more general than the inferred type" $ do
getType (EAnn (ELit (LInt 0)) (TPol "a")) `shouldSatisfy` isLeft
it "should fail if the annotated type is an arrow but the annotated type is not" $ do
getType (EAnn (EAbs "x" (EId "x")) (TPol "a")) `shouldSatisfy` isLeft
infer_eid = describe "algoW used on EId" $ do
it "should fail if the variable is not added to the environment" $ do
property $ \x -> getType (EId (Ident (x :: String))) `shouldSatisfy` isLeft
it "should succeed if the type exist in the environment" $ do
property $ \x -> do
let env = Env 0 mempty mempty
let t = Forall [] (TPol "a")
let ctx = Ctx (M.singleton (Ident (x :: String)) t)
getTypeC env ctx (EId (Ident x)) `shouldBe` Right (TPol "a")
infer_eabs = describe "algoW used on EAbs" $ do
it "should infer the argument type as int if the variable is used as an int" $ do
let lambda = EAbs "x" (EAdd (EId "x") (ELit (LInt 0)))
getType lambda `shouldBe` Right (TArr (TMono "Int") (TMono "Int"))
it "should infer the argument type as polymorphic if it is not used in the lambda" $ do
let lambda = EAbs "x" (ELit (LInt 0))
getType lambda `shouldSatisfy` isArrowPolyToMono
it "should infer a variable as function if used as one" $ do
let lambda = EAbs "f" (EAbs "x" (EApp (EId "f") (EId "x")))
let isOk (Right (TArr (TArr (TPol _) (TPol _)) (TArr (TPol _) (TPol _)))) = True
isOk _ = False
getType lambda `shouldSatisfy` isOk
infer_eapp = describe "algoW used on EApp" $ do
it "should fail if a variable is applied to itself (occurs check)" $ do
property $ \x -> do
let env = Env 0 mempty mempty
let t = Forall [] (TPol "a")
let ctx = Ctx (M.singleton (Ident (x :: String)) t)
getTypeC env ctx (EApp (EId (Ident x)) (EId (Ident x))) `shouldBe` Left "Occurs check failed"
isArrowPolyToMono :: Either Error Type -> Bool
isArrowPolyToMono (Right (TArr (TPol _) (TMono _))) = True
isArrowPolyToMono _ = False
-- | Empty environment
getType :: Exp -> Either Error Type
getType e = pure fst <*> run (inferExp e)
-- | Custom environment
getTypeC :: Env -> Ctx -> Exp -> Either Error Type
getTypeC env ctx e = pure fst <*> runC env ctx (inferExp e)