From cf0866c099a601c262dac42ad714b7210b6880f7 Mon Sep 17 00:00:00 2001
From: Michael Williamson <mike@zwobble.org>
Date: Thu, 23 Apr 2026 11:39:57 +0100
Subject: Parse struct definition fields

---
 .../ast/untyped/UntypedStructDefinitionNode.java   |  3 ++
 .../zwobble/hobgoblin/compiler/parser/Parser.java  | 35 ++++++++++++++++
 .../parser/ParserStructDefinitionTests.java        | 46 ++++++++++++++++++++++
 3 files changed, 84 insertions(+)

(limited to 'src')

diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/ast/untyped/UntypedStructDefinitionNode.java b/src/main/java/org/zwobble/hobgoblin/compiler/ast/untyped/UntypedStructDefinitionNode.java
index e86b141..50f1156 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/ast/untyped/UntypedStructDefinitionNode.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/ast/untyped/UntypedStructDefinitionNode.java
@@ -2,8 +2,11 @@ package org.zwobble.hobgoblin.compiler.ast.untyped;
 
 import org.zwobble.hobgoblin.compiler.sources.Source;
 
+import java.util.List;
+
 public record UntypedStructDefinitionNode(
     String name,
+    List<UntypedStructFieldDefinitionNode> fields,
     Source source
 ) implements UntypedNamespaceStatementNode {
 }
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/parser/Parser.java b/src/main/java/org/zwobble/hobgoblin/compiler/parser/Parser.java
index 90f7f66..7a50bf5 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/parser/Parser.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/parser/Parser.java
@@ -39,12 +39,25 @@ public class Parser {
 
     static UntypedNamespaceStatementNode parseNamespaceStatement(
         TokenIterator tokens
+    ) {
+        return parseStructDefinition(tokens);
+    }
+
+    private static UntypedStructDefinitionNode parseStructDefinition(
+        TokenIterator tokens
     ) {
         var start = tokens.startPosition();
 
         tokens.skip(TokenType.KEYWORD_STRUCT);
         var name = tokens.next(TokenType.IDENTIFIER);
         tokens.skip(TokenType.SYMBOL_BRACE_OPEN);
+
+        var fields = parseMany(
+            () -> tokens.isNext(TokenType.SYMBOL_BRACE_CLOSE),
+            () -> parseStructFieldDefinition(tokens),
+            () -> true
+        );
+
         tokens.skip(TokenType.SYMBOL_BRACE_CLOSE);
 
         var end = tokens.endPosition();
@@ -52,6 +65,28 @@ public class Parser {
 
         return new UntypedStructDefinitionNode(
             name.charSequence().toString(),
+            fields,
+            source
+        );
+    }
+
+    private static UntypedStructFieldDefinitionNode parseStructFieldDefinition(
+        TokenIterator tokens
+    ) {
+        var start = tokens.startPosition();
+
+        tokens.skip(TokenType.KEYWORD_FIELD);
+        var name = tokens.next(TokenType.IDENTIFIER);
+        tokens.skip(TokenType.SYMBOL_COLON);
+        var type = parseTypeLevelExpression(tokens);
+        tokens.skip(TokenType.SYMBOL_SEMICOLON);
+
+        var end = tokens.endPosition();
+        var source = createSource(start, end);
+
+        return new UntypedStructFieldDefinitionNode(
+            name.charSequence().toString(),
+            type,
             source
         );
     }
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/parser/ParserStructDefinitionTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/parser/ParserStructDefinitionTests.java
index 8c692fd..9dae394 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/parser/ParserStructDefinitionTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/parser/ParserStructDefinitionTests.java
@@ -2,6 +2,8 @@ package org.zwobble.hobgoblin.compiler.parser;
 
 import org.junit.jupiter.api.Test;
 import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedStructDefinitionNode;
+import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedStructFieldDefinitionNode;
+import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedTypeLevelReferenceNode;
 
 import static org.zwobble.hobgoblin.compiler.parser.ParserTesting.parseString;
 import static org.zwobble.precisely.AssertThat.assertThat;
@@ -24,4 +26,48 @@ public class ParserStructDefinitionTests {
             has("name", UntypedStructDefinitionNode::name, equalTo("Point"))
         ));
     }
+
+    @Test
+    public void structWithFields() {
+        var source = """
+            struct Point {
+                field x: Int;
+                field y: Int;
+            }""";
+
+        var node = parseString(
+            source,
+            Parser::parseNamespaceStatement
+        );
+
+        assertThat(node, instanceOf(
+            UntypedStructDefinitionNode.class,
+            has("fields", UntypedStructDefinitionNode::fields, isSequence(
+                instanceOf(
+                    UntypedStructFieldDefinitionNode.class,
+                    has("name", UntypedStructFieldDefinitionNode::name, equalTo("x")),
+                    has(
+                        "type",
+                        UntypedStructFieldDefinitionNode::type,
+                        instanceOf(
+                            UntypedTypeLevelReferenceNode.class,
+                            has("name", UntypedTypeLevelReferenceNode::name, equalTo("Int"))
+                        )
+                    )
+                ),
+                instanceOf(
+                    UntypedStructFieldDefinitionNode.class,
+                    has("name", UntypedStructFieldDefinitionNode::name, equalTo("y")),
+                    has(
+                        "type",
+                        UntypedStructFieldDefinitionNode::type,
+                        instanceOf(
+                            UntypedTypeLevelReferenceNode.class,
+                            has("name", UntypedTypeLevelReferenceNode::name, equalTo("Int"))
+                        )
+                    )
+                )
+            ))
+        ));
+    }
 }
-- 
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