Fix precedence inconsistency bug (#2470)

Precedence inconsistency was not always correctly detected.
anoma · Oct 25, 2023 · ef1148b · ef1148b
1 parent 830b3be
commit ef1148b
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Showing 3 changed files with 13 additions and 1 deletion.
diff --git a/src/Juvix/Compiler/Concrete/Translation/FromParsed/Analysis/Scoping.hs b/src/Juvix/Compiler/Concrete/Translation/FromParsed/Analysis/Scoping.hs
@@ -707,7 +707,7 @@ resolveFixitySyntaxDef fdef@FixitySyntaxDef {..} = topBindings $ do
       belowPrec = fromIntegral $ maximum (minInt + 1 : maybe [] (map (getPrec tab)) above)
       abovePrec :: Integer
       abovePrec = fromIntegral $ minimum (maxInt - 1 : maybe [] (map (getPrec tab)) below)
-  when (belowPrec >= abovePrec + 1) $
+  when (belowPrec + 1 >= abovePrec) $
     throw (ErrPrecedenceInconsistency (PrecedenceInconsistencyError fdef))
   when (isJust same && not (null below && null above)) $
     throw (ErrPrecedenceInconsistency (PrecedenceInconsistencyError fdef))

diff --git a/test/Scope/Negative.hs b/test/Scope/Negative.hs
@@ -330,6 +330,13 @@ scoperErrorTests =
       $ \case
         ErrIncomparablePrecedences {} -> Nothing
         _ -> wrongError,
+    NegTest
+      "Precedence inconsistency"
+      $(mkRelDir ".")
+      $(mkRelFile "PrecedenceInconsistency.juvix")
+      $ \case
+        ErrPrecedenceInconsistency {} -> Nothing
+        _ -> wrongError,
     NegTest
       "Alias cycle"
       $(mkRelDir ".")

diff --git a/tests/negative/PrecedenceInconsistency.juvix b/tests/negative/PrecedenceInconsistency.juvix
@@ -0,0 +1,5 @@
+module PrecedenceInconsistency;
+
+syntax fixity f1 := binary {assoc := left};
+syntax fixity f2 := binary {assoc := left; same := f1};
+syntax fixity f3 := binary {assoc := left; above := [f1]; below := [f2]};