Convert if to when

1 files changed, 19 insertions, 21 deletions

diff --git a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
index c9d4f811..8ada73c2 100644
--- a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
+++ b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
@@ -572,27 +572,25 @@ public class TypeChecker {
     }
 
     private static Type fieldType(Type receiverType, String fieldName, Source source, TypeCheckerContext context) {
-        if (receiverType instanceof StructType receiverTypeStruct) {
-            var structTypeInfo = context.structTypeInfo(receiverTypeStruct, source);
-
-            return structTypeInfo.fieldType(fieldName)
-                .orElseThrow(() -> new NoSuchFieldError(receiverTypeStruct, fieldName, source));
-        } else if (receiverType instanceof NamespaceType receiverTypeNamespace) {
-            var namespaceTypeInfo = context.namespaceTypeInfo(receiverTypeNamespace, source);
-
-            return namespaceTypeInfo.fieldType(fieldName)
-                .orElseThrow(() -> new NoSuchFieldError(receiverTypeNamespace, fieldName, source));
-        } else if (
-            receiverType instanceof TypeLevelValueType receiverTypeTypeLevelValue &&
-            receiverTypeTypeLevelValue.value() instanceof UserDefinedEffect effect
-        ) {
-            var effectInfo = context.userDefinedEffectInfo(effect, source);
-
-            return effectInfo.methodType(fieldName)
-                .orElseThrow(() -> new NoSuchFieldError(receiverType, fieldName, source))
-                .withEffect(effect);
-        } else {
-            throw new NoSuchFieldError(receiverType, fieldName, source);
+        switch (receiverType) {
+            case StructType receiverTypeStruct -> {
+                var structTypeInfo = context.structTypeInfo(receiverTypeStruct, source);
+                return structTypeInfo.fieldType(fieldName)
+                    .orElseThrow(() -> new NoSuchFieldError(receiverTypeStruct, fieldName, source));
+            }
+            case NamespaceType receiverTypeNamespace -> {
+                var namespaceTypeInfo = context.namespaceTypeInfo(receiverTypeNamespace, source);
+                return namespaceTypeInfo.fieldType(fieldName)
+                    .orElseThrow(() -> new NoSuchFieldError(receiverTypeNamespace, fieldName, source));
+            }
+            case TypeLevelValueType receiverTypeTypeLevelValue when receiverTypeTypeLevelValue.value() instanceof UserDefinedEffect effect -> {
+                var effectInfo = context.userDefinedEffectInfo(effect, source);
+                return effectInfo.methodType(fieldName)
+                    .orElseThrow(() -> new NoSuchFieldError(receiverType, fieldName, source))
+                    .withEffect(effect);
+            }
+            default ->
+                throw new NoSuchFieldError(receiverType, fieldName, source);
         }
     }