Allow capture of vars in effect handler methods in type checker

1 files changed, 43 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTryTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTryTests.java
index f1a68abf..2d60446b 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTryTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTryTests.java
@@ -626,4 +626,47 @@ public class TypeCheckerTryTests {
             () -> typeCheckExpression(untyped, context)
         );
     }
+
+    @Test
+    public void handlerMethodMayCaptureVars() {
+        var handledEffect = Effects.userDefined(NAMESPACE_NAME, "HandledEffect");
+        var untyped = UntypedTryNode.builder()
+            .withHandledEffect(Untyped.typeLevelReference(handledEffect.name()))
+            .addHandlerMethod(
+                UntypedTryHandlerMethodNode.builder()
+                    .addStatement(Untyped.resume(Untyped.reference("x")))
+                    .withName("mark")
+                    .build()
+            )
+            .build();
+        var context = TypeCheckerContext.EMPTY
+            .addUserDefinedEffectInfo(
+                handledEffect,
+                UserDefinedEffectInfo.builder()
+                    .addMethod("mark", FunctionType.builder().withReturnType(Types.INT).build())
+                    .build()
+            )
+            .enterFunction(
+                P.map(
+                    Map.entry(handledEffect.name(), Variable.defined(Types.effectType(handledEffect), VariableType.CONSTANT)),
+                    Map.entry("x", Variable.defined(Types.INT, VariableType.VAR))
+                ),
+                Effects.NONE,
+                Optional.empty()
+            );
+
+        var result = typeCheckExpression(untyped, context);
+
+        assertThat(
+            result.value(),
+            isTypedTryNode()
+                .withHandlerMethods(isSequence(
+                    isTypedTryHandlerMethodNode()
+                        .withName("mark")
+                        .withBodyBlock(isTypedBlockNode(isSequence(
+                            isTypedResumeNode(isTypedReferenceNode("x", Types.INT))
+                        )))
+                ))
+        );
+    }
 }