Check for namespace name when defining struct

2 files changed, 14 insertions, 2 deletions

diff --git a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
index 54e9d9b9..ad3ed297 100644
--- a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
+++ b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
@@ -831,8 +831,10 @@ public class TypeChecker {
         return new TypeCheckSteps<TypedStructDefinitionNode>() {
             @Override
             public TypeCheckerContext declareTypes(TypeCheckerContext context) {
-                // TODO: better error
-                var type = new StructType(context.namespaceName().orElseThrow(), untyped.name());
+                var namespaceName = context.namespaceName()
+                    .orElseThrow(() -> new CannotDefineStructOutsideOfNamespace(untyped.source()));
+
+                var type = new StructType(namespaceName, untyped.name());
 
                 context = context.addLexicalState(untyped.name(), type);
 
diff --git a/src/main/java/org/shedlang/compiler/typechecker/errors/CannotDefineStructOutsideOfNamespace.java b/src/main/java/org/shedlang/compiler/typechecker/errors/CannotDefineStructOutsideOfNamespace.java
new file mode 100644
index 00000000..6e8810eb
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/typechecker/errors/CannotDefineStructOutsideOfNamespace.java
@@ -0,0 +1,10 @@
+package org.shedlang.compiler.typechecker.errors;
+
+import org.shedlang.compiler.errors.InternalCompilerError;
+import org.shedlang.compiler.sources.Source;
+
+public class CannotDefineStructOutsideOfNamespace extends InternalCompilerError {
+    public CannotDefineStructOutsideOfNamespace(Source source) {
+        super("Cannot define struct outside of namespace", source);
+    }
+}