Check struct type info is present

2 files changed, 29 insertions, 1 deletions

diff --git a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
index 73713a65..bd5b43fd 100644
--- a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
+++ b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
@@ -411,7 +411,11 @@ public class TypeChecker {
             untyped.fieldName()
         );
 
-        var fieldType = structTypeInfo.orElseThrow().fieldType(untyped.fieldName());
+        if (structTypeInfo.isEmpty()) {
+            throw new MissingStructTypeInfoError(receiverType, untyped.source());
+        }
+
+        var fieldType = structTypeInfo.get().fieldType(untyped.fieldName());
 
         if (fieldType.isEmpty()) {
             throw new NoSuchFieldError(receiverType, untyped.fieldName(), untyped.source());
diff --git a/src/main/java/org/shedlang/compiler/typechecker/errors/MissingStructTypeInfoError.java b/src/main/java/org/shedlang/compiler/typechecker/errors/MissingStructTypeInfoError.java
new file mode 100644
index 00000000..b7582135
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/typechecker/errors/MissingStructTypeInfoError.java
@@ -0,0 +1,24 @@
+package org.shedlang.compiler.typechecker.errors;
+
+import org.shedlang.compiler.errors.InternalCompilerError;
+import org.shedlang.compiler.sources.Source;
+import org.shedlang.compiler.types.StructType;
+
+public class MissingStructTypeInfoError extends InternalCompilerError {
+    private final StructType type;
+    private final Source source;
+
+    public MissingStructTypeInfoError(StructType type, Source source) {
+        super("Missing type info for struct " + type);
+        this.type = type;
+        this.source = source;
+    }
+
+    public StructType type() {
+        return type;
+    }
+
+    public Source source() {
+        return source;
+    }
+}