Add basic inference of type level args

1 files changed, 42 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java
index 8fb1faf5..1dcfc36a 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java
@@ -423,4 +423,46 @@ public class TypeCheckerCallTests {
                 .withType(Types.constructedType(typeConstructor, List.of(Types.STRING)))
         );
     }
+
+    @Test
+    public void canCallGenericStructWithImplicitTypeArgs() {
+        var untyped = UntypedCallNode.builder()
+            .withReceiver(Untyped.reference("Box"))
+            .addNamedArg(Untyped.namedArg("value", Untyped.stringLiteral("Bob")))
+            .build();
+        var structType = Types.struct(NamespaceName.of("Example"), "Box");
+        var typeConstructor = Types.typeConstructor(
+            List.of(TypeParam.forStructType(structType, "T")),
+            structType
+        );
+        var structTypeInfo = StructTypeInfo.builder()
+            .addField("value", TypeParam.forStructType(structType, "T"))
+            .build();
+        var context = TypeCheckerContext.EMPTY
+            .enterGlobal(P.map(
+                Map.entry("String", Types.metaType(Types.STRING)),
+                Map.entry("Box", Types.typeConstructorType(typeConstructor))
+            ))
+            .addStructTypeInfo(structType, structTypeInfo);
+
+        var typed = typeCheckExpression(untyped, context);
+
+        assertThat(
+            typed.value(),
+            isTypedCallNode()
+                .withReceiver(isTypedReferenceNode(
+                    "Box",
+                    Types.typeConstructorType(typeConstructor)
+                ))
+                .withArgs(
+                    isTypedArgsNode()
+                        .withPositional(isSequence())
+                        .withNamed(isSequence(
+                            isTypedNamedArgNode("value", isTypedStringLiteralNode("Bob"))
+                        ))
+                )
+                .withHasEffects(false)
+                .withType(Types.constructedType(typeConstructor, List.of(Types.STRING)))
+        );
+    }
 }