Give unary minus higher precedence, fixes #8

rockofox · Dec 28, 2023 · c30c053 · c30c053
1 parent 68ecd7d
commit c30c053
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Showing 2 changed files with 15 additions and 2 deletions.
diff --git a/lib/Parser.hs b/lib/Parser.hs
@@ -83,6 +83,8 @@ binOpTable :: [[Operator Parser Expr]]
 binOpTable =
     [ [prefix "^" Flexible]
     , [prefix "$" StrictEval]
+    , [prefix "!" Not]
+    , [prefix "-" UnaryMinus]
     , [binary "**" Power, binary "*" Mul, binary "/" Div]
     , [binary "%" Modulo]
     , [binary "+" Add, binary "-" Sub]
@@ -93,8 +95,6 @@ binOpTable =
     , [binary ":" ListConcat]
     , [binary "==" Eq, binary "!=" Neq, binary "<=" Le, binary ">=" Ge, binary "<" Lt, binary ">" Gt]
     , [binary "&&" And, binary "||" Or]
-    , [prefix "!" Not]
-    , [prefix "-" UnaryMinus]
     ]
 
 binary :: Text -> (Expr -> Expr -> Expr) -> Operator Parser Expr

diff --git a/tests/ParserSpec.hs b/tests/ParserSpec.hs
@@ -103,3 +103,16 @@ spec = do
                     parserCompilerFlags
                 `shouldBe` Right
                     (Program [FuncCall "filter" [FuncCall "==" [IntLit 1] anyPosition, ListLit [IntLit 1, IntLit 2, IntLit 3]] anyPosition])
+    describe "Unary minus" $ do
+        it "Should parse unary minus" $
+            parseProgram "-1" parserCompilerFlags
+                `shouldBe` Right
+                    (Program [UnaryMinus (IntLit 1)])
+        it "Should be able to use negative numbers in multiplication" $
+            parseProgram "1 *-1" parserCompilerFlags
+                `shouldBe` Right
+                    (Program [Mul (IntLit 1) (UnaryMinus (IntLit 1))])
+        it "Should be able to negate expressions in parentheses" $
+            parseProgram "2 * -(3-x*5)" parserCompilerFlags
+                `shouldBe` Right
+                    (Program [Mul (IntLit 2) (UnaryMinus (Sub (IntLit 3) (Mul (Var "x" anyPosition) (IntLit 5))))])