tidying up, more tests

haskell-experiments/src/ArithmeticParser.hs

@@ -7,7 +7,7 @@ import Text.Megaparsec.Char
 import qualified Text.Megaparsec.Char.Lexer as L
 import Data.Void
 import Data.Text (Text)
-import qualified Data.Text as T
+-- import qualified Data.Text as T
 
 -- Type aliases for convenience
 type Parser = Parsec Void Text
@@ -95,17 +95,3 @@ chainl1 p op = do
   where
     rest x = (do f <- op; y <- p; rest (f x y)) <|> pure x
 
--- ┌───────────────────────────────┐
--- │           Examples            │
--- └───────────────────────────────┘
-examples :: [(Text, Maybe Expr)]
-examples =
-  [ ("42",                    Just $ ENumber 42)
-  , ("-7 + 3",                Just $ EAdd (ENumber (-7)) (ENumber 3))
-  , ("2 * (3 + 4)",           Just $ EMul (ENumber 2) (EAdd (ENumber 3) (ENumber 4)))
-  , ("10 - 2 * 3",            Just $ ESub (ENumber 10) (EMul (ENumber 2) (ENumber 3)))
-  , ("(8 / 2) + 1",           Just $ EAdd (EDiv (ENumber 8) (ENumber 2)) (ENumber 1))
-  , ("",                      Nothing)
-  , ("5 +",                   Nothing)   -- incomplete
-  , ("2 ** 3",                Nothing)   -- ** not supported
-  ]

haskell-experiments/test/Test/ArithmeticParserSpec.hs

@@ -14,6 +14,7 @@ module Test.ArithmeticParserSpec where
 import Test.Hspec
 
 import ArithmeticParser
+import Data.Either
 
 spec :: Spec
 spec = do
@@ -25,6 +26,6 @@ spec = do
       parseExpr "10 - 2 * 3" `shouldBe` Right (ESub (ENumber 10) (EMul (ENumber 2) (ENumber 3)))
       parseExpr "(8 / 2) + 1" `shouldBe` Right (EAdd (EDiv (ENumber 8) (ENumber 2)) (ENumber 1))
       parseExpr "2 + 3 * (10 - 4)" `shouldBe` Right (EAdd (ENumber 2) (EMul (ENumber 3) (ESub (ENumber 10) (ENumber 4))))
-
+      isLeft (parseExpr "") `shouldBe` True         -- missing expression
-
+      isLeft (parseExpr "5 +") `shouldBe` True      -- incomplete
-
+      isLeft (parseExpr "2 ** 3") `shouldBe` True   -- not supported