76 lines
3.6 KiB
Haskell
76 lines
3.6 KiB
Haskell
import Data.Char (isAlpha)
|
|
import qualified Data.Text as T
|
|
import Generic.Random (genericArbitraryRec, uniform)
|
|
import LambdaCalculus
|
|
import LambdaCalculus.Parser
|
|
import Test.QuickCheck
|
|
import Test.Tasty
|
|
import Test.Tasty.HUnit
|
|
import Test.Tasty.QuickCheck
|
|
import TextShow (showt)
|
|
|
|
instance Arbitrary Expression where
|
|
arbitrary = genericArbitraryRec uniform
|
|
|
|
instance Arbitrary T.Text where
|
|
arbitrary = T.pack <$> listOf1 (elements $ ['A'..'Z'] ++ ['a'..'z'])
|
|
|
|
-- These are terms which have complex reduction steps and
|
|
-- are likely to catch bugs in the substitution function, if there are any.
|
|
-- However, they don't have any particular computational *meaning*,
|
|
-- so the names for them are somewhat arbitrary.
|
|
|
|
-- This should evaluate to `y y`.
|
|
dfi :: Expression
|
|
dfi = Application d (Application f i)
|
|
where
|
|
d = Abstraction "x" $ Application (Variable "x") (Variable "x")
|
|
f = Abstraction "f" $ Application (Variable "f") (Application (Variable "f") (Variable "y"))
|
|
i = Abstraction "x" $ Variable "x"
|
|
|
|
-- This should evalaute to `y`.
|
|
ttttt :: Expression
|
|
ttttt = Application (Application (Application f t) (Abstraction "x" (Variable "x"))) (Variable "y")
|
|
where
|
|
t = Abstraction "f" $ Abstraction "x" $
|
|
Application (Variable "f") (Application (Variable "f") (Variable "x"))
|
|
f = Abstraction "T" $ Abstraction "f" $ Abstraction "x" $
|
|
Application (Application
|
|
(Application (Variable "T")
|
|
(Application (Variable "T")
|
|
(Application (Variable "T")
|
|
(Application (Variable "T")
|
|
(Variable "T")))))
|
|
(Variable "f"))
|
|
(Variable "x")
|
|
|
|
prop_parseExpression_inverse :: Expression -> Bool
|
|
prop_parseExpression_inverse expr = Right expr == parseExpression (showt expr)
|
|
|
|
main :: IO ()
|
|
main = defaultMain $
|
|
testGroup "Tests"
|
|
[ testGroup "Evaluator tests"
|
|
[ testCase "DFI" $ eagerEval dfi @?= Application (Variable "y") (Variable "y")
|
|
, testCase "ttttt" $ eagerEval ttttt @?= Variable "y"
|
|
]
|
|
, testGroup "Parser tests"
|
|
[ testGroup "Unit tests"
|
|
[ testCase "identity" $ parseExpression "\\x.x" @?= Right (Abstraction "x" $ Variable "x")
|
|
, testCase "unary application" $ parseExpression "(x)" @?= Right (Variable "x")
|
|
, testCase "application shorthand" $ parseExpression "a b c d" @?= Right (Application (Application (Application (Variable "a") (Variable "b")) (Variable "c")) (Variable "d"))
|
|
, testCase "let" $ parseExpression "let x = \\y.y in x" @?= Right (Application (Abstraction "x" (Variable "x")) (Abstraction "y" (Variable "y")))
|
|
, testCase "multi-let" $ parseExpression "let x = y; y = z in x y" @?= Right (Application (Abstraction "x" (Application (Abstraction "y" (Application (Variable "x") (Variable "y"))) (Variable "z"))) (Variable "y"))
|
|
, testCase "ttttt" $ parseExpression "(\\T f x.(T (T (T (T T)))) f x) (\\f x.f (f x)) (\\x.x) y"
|
|
@?= Right ttttt
|
|
, testGroup "Redundant whitespace"
|
|
[ testCase "around variable" $ parseExpression " x " @?= Right (Variable "x")
|
|
, testCase "around lambda" $ parseExpression " \\ x y . x " @?= Right (Abstraction "x" $ Abstraction "y" $ Variable "x")
|
|
, testCase "around application" $ parseExpression " ( x (y ) ) " @?= Right (Application (Variable "x") (Variable "y"))
|
|
, testCase "around let" $ parseExpression " let x=(y)in x " @?= Right (Application (Abstraction "x" (Variable "x")) (Variable "y"))
|
|
]
|
|
]
|
|
, testProperty "parseExpression is the left inverse of show" prop_parseExpression_inverse
|
|
]
|
|
]
|