Add type checking for unit literal

3 files changed, 18 insertions, 1 deletions

diff --git a/src/main/java/org/shedlang/compiler/ast/untyped/UntypedExpressionNode.java b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedExpressionNode.java
index 60f80022..a8c068e0 100644
--- a/src/main/java/org/shedlang/compiler/ast/untyped/UntypedExpressionNode.java
+++ b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedExpressionNode.java
@@ -1,5 +1,5 @@
 package org.shedlang.compiler.ast.untyped;
 
 public sealed interface UntypedExpressionNode extends UntypedNode
-    permits UntypedBinaryOperationNode, UntypedBoolLiteralNode, UntypedCallNode, UntypedFieldAccessNode, UntypedFunctionExpressionNode, UntypedIfNode, UntypedIntLiteralNode, UntypedReferenceNode, UntypedStringLiteralNode, UntypedTryNode, UntypedTupleNode, UntypedWhenNode {
+    permits UntypedBinaryOperationNode, UntypedBoolLiteralNode, UntypedCallNode, UntypedFieldAccessNode, UntypedFunctionExpressionNode, UntypedIfNode, UntypedIntLiteralNode, UntypedReferenceNode, UntypedStringLiteralNode, UntypedTryNode, UntypedTupleNode, UntypedUnitLiteralNode, UntypedWhenNode {
 }
diff --git a/src/main/java/org/shedlang/compiler/ast/untyped/UntypedUnitLiteralNode.java b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedUnitLiteralNode.java
new file mode 100644
index 00000000..4ca98c78
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedUnitLiteralNode.java
@@ -0,0 +1,6 @@
+package org.shedlang.compiler.ast.untyped;
+
+import org.shedlang.compiler.sources.Source;
+
+public record UntypedUnitLiteralNode(Source source) implements UntypedExpressionNode {
+}
diff --git a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
index 6dd1a3f3..2991c344 100644
--- a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
+++ b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
@@ -430,6 +430,9 @@ public class TypeChecker {
             case UntypedTupleNode untypedTuple ->
                 typeCheckTuple(untypedTuple, context);
 
+            case UntypedUnitLiteralNode untypedUnit ->
+                typeCheckUnitLiteral(untypedUnit, context);
+
             case UntypedWhenNode untypedWhen ->
                 typeCheckWhen(untypedWhen, context);
         };
@@ -1520,6 +1523,14 @@ public class TypeChecker {
         };
     }
 
+    private static TypeCheckerResult<TypedExpressionNode> typeCheckUnitLiteral(
+        UntypedUnitLiteralNode untyped,
+        TypeCheckerContext context
+    ) {
+        return context.toResult(new TypedUnitLiteralNode(untyped.source()));
+    }
+
+
     private static TypeCheckerResult<TypedWhenNode> typeCheckWhen(
         UntypedWhenNode untyped,
         TypeCheckerContext context