4 files changed, 25 insertions, 1 deletions
diff --git a/src/main/java/org/shedlang/compiler/ast/untyped/UntypedNamespaceStatementNode.java b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedNamespaceStatementNode.java
index 16eafcf9..ac229649 100644
--- a/src/main/java/org/shedlang/compiler/ast/untyped/UntypedNamespaceStatementNode.java
+++ b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedNamespaceStatementNode.java
@@ -1,4 +1,4 @@
 package org.shedlang.compiler.ast.untyped;
 
-public sealed interface UntypedNamespaceStatementNode extends UntypedNode permits UntypedAssignNode, UntypedFunctionDefinitionNode, UntypedStructDefinitionNode {
+public sealed interface UntypedNamespaceStatementNode extends UntypedNode permits UntypedAssignNode, UntypedFunctionDefinitionNode, UntypedStructDefinitionNode, UntypedSumTypeDefinitionNode {
 }
diff --git a/src/main/java/org/shedlang/compiler/ast/untyped/UntypedSumTypeDefinitionNode.java b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedSumTypeDefinitionNode.java
new file mode 100644
index 00000000..3a49f46e
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedSumTypeDefinitionNode.java
@@ -0,0 +1,10 @@
+package org.shedlang.compiler.ast.untyped;
+
+import org.shedlang.compiler.sources.Source;
+
+public record UntypedSumTypeDefinitionNode(
+    String name,
+    UntypedTypeLevelExpressionNode variants,
+    Source source
+) implements UntypedNamespaceStatementNode {
+}
diff --git a/src/main/java/org/shedlang/compiler/typechecker/DeclaredVariables.java b/src/main/java/org/shedlang/compiler/typechecker/DeclaredVariables.java
index a6cfde24..27be00db 100644
--- a/src/main/java/org/shedlang/compiler/typechecker/DeclaredVariables.java
+++ b/src/main/java/org/shedlang/compiler/typechecker/DeclaredVariables.java
@@ -78,6 +78,13 @@ class DeclaredVariables {
                     VariableType.CONSTANT,
                     struct.source()
                 ));
+
+            case UntypedSumTypeDefinitionNode sumType ->
+                variables.plus(new DeclaredVariable(
+                    sumType.name(),
+                    VariableType.CONSTANT,
+                    sumType.source()
+                ));
         };
     }
 
diff --git a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
index 84e87182..7c3741e2 100644
--- a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
+++ b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
@@ -745,6 +745,10 @@ public class TypeChecker {
                         Set.of()
                     );
                 }
+
+                case UntypedSumTypeDefinitionNode untypedSumTypeDefinition -> {
+                    throw new UnsupportedOperationException("TODO");
+                }
             }
         }
 
@@ -790,6 +794,9 @@ public class TypeChecker {
 
             case UntypedStructDefinitionNode structDefinition ->
                 typeCheckStepsStructDefinition(structDefinition);
+
+            case UntypedSumTypeDefinitionNode sumTypeDefinition ->
+                throw new UnsupportedOperationException("TODO");
         };
     }