Extend AVR List/Map ban to class and struct field declarations

src/semantic-analyzer.js

@@ -212,6 +212,22 @@ class SemanticAnalyzer {
       case 'StructDeclaration':
         // Declare struct name
         this.declare(stmt.name);
+        // Check struct fields for List/Map usage on AVR boards
+        if (this.config && this.config.isAVRBoard()) {
+          if (stmt.fields) {
+            stmt.fields.forEach(field => {
+              if (field.type && RESTRICTED_COLLECTION_TYPES.includes(field.type)) {
+                const board = this.config.options.board;
+                this.addError(
+                  `Collection type '${field.type}' is not supported on AVR targets (${board}) due to insufficient RAM.\n` +
+                  `  AVR boards have very limited memory and cannot support std::vector and std::map.\n` +
+                  `  Consider using arrays or simpler data structures, or target a board with more RAM (e.g., ESP32).`,
+                  stmt.line
+                );
+              }
+            });
+          }
+        }
         break;
 
       case 'FunctionDeclaration':
@@ -339,6 +355,19 @@ class SemanticAnalyzer {
     // Declare all properties
     if (stmt.properties) {
       stmt.properties.forEach(prop => {
+        // Check for List/Map usage on AVR boards
+        if (this.config && this.config.isAVRBoard()) {
+          if (prop.propertyType && RESTRICTED_COLLECTION_TYPES.includes(prop.propertyType)) {
+            const board = this.config.options.board;
+            this.addError(
+              `Collection type '${prop.propertyType}' is not supported on AVR targets (${board}) due to insufficient RAM.\n` +
+              `  AVR boards have very limited memory and cannot support std::vector and std::map.\n` +
+              `  Consider using arrays or simpler data structures, or target a board with more RAM (e.g., ESP32).`,
+              stmt.line
+            );
+          }
+        }
+
         this.declare(prop.name);
         if (prop.init) {
           this.analyzeExpression(prop.init);

tests/semantic-analyzer.test.js

@@ -455,4 +455,169 @@ describe('Semantic Analyzer - AVR Board Restrictions', () => {
     expect(result.error).toContain('Collection type \'List\' is not supported on AVR targets');
     expect(result.error).toContain('Collection type \'Map\' is not supported on AVR targets');
   });
+
+  test('should reject List type in class field on arduino_uno', () => {
+    const source = `
+      @main
+      config {
+        board: arduino_uno,
+        clock: 16MHz
+      }
+
+      class DataLogger {
+        mut List data
+
+        constructor() {
+          self.data = new List()
+        }
+
+        fn addReading(int value) {
+          self.data.push(value)
+        }
+      }
+
+      on start {
+        mut DataLogger logger = new DataLogger()
+      }
+    `;
+
+    const result = compile(source);
+    expect(result.success).toBe(false);
+    expect(result.error).toContain('Collection type \'List\' is not supported on AVR targets');
+    expect(result.error).toContain('arduino_uno');
+    expect(result.error).toContain('insufficient RAM');
+  });
+
+  test('should reject Map type in class field on arduino_uno', () => {
+    const source = `
+      @main
+      config {
+        board: arduino_uno,
+        clock: 16MHz
+      }
+
+      class Configuration {
+        mut Map settings
+
+        constructor() {
+          self.settings = new Map()
+        }
+
+        fn setSetting(int key, int value) {
+          self.settings.set(key, value)
+        }
+      }
+
+      on start {
+        mut Configuration cfg = new Configuration()
+      }
+    `;
+
+    const result = compile(source);
+    expect(result.success).toBe(false);
+    expect(result.error).toContain('Collection type \'Map\' is not supported on AVR targets');
+    expect(result.error).toContain('arduino_uno');
+    expect(result.error).toContain('insufficient RAM');
+  });
+
+  test('should allow List type in class field on esp32', () => {
+    const source = `
+      @main
+      config {
+        board: esp32,
+        clock: 16MHz
+      }
+
+      class DataLogger {
+        mut List data
+
+        constructor() {
+          self.data = new List()
+        }
+
+        fn addReading(int value) {
+          self.data.push(value)
+        }
+      }
+
+      on start {
+        mut DataLogger logger = new DataLogger()
+      }
+    `;
+
+    const result = compile(source);
+    expect(result.success).toBe(true);
+  });
+
+  test('should reject List type in struct field on arduino_uno', () => {
+    const source = `
+      @main
+      config {
+        board: arduino_uno,
+        clock: 16MHz
+      }
+
+      struct DataPoint {
+        List values
+        int timestamp
+      }
+
+      on start {
+        print("test")
+      }
+    `;
+
+    const result = compile(source);
+    expect(result.success).toBe(false);
+    expect(result.error).toContain('Collection type \'List\' is not supported on AVR targets');
+    expect(result.error).toContain('arduino_uno');
+    expect(result.error).toContain('insufficient RAM');
+  });
+
+  test('should reject Map type in struct field on arduino_uno', () => {
+    const source = `
+      @main
+      config {
+        board: arduino_uno,
+        clock: 16MHz
+      }
+
+      struct Config {
+        Map settings
+        int version
+      }
+
+      on start {
+        print("test")
+      }
+    `;
+
+    const result = compile(source);
+    expect(result.success).toBe(false);
+    expect(result.error).toContain('Collection type \'Map\' is not supported on AVR targets');
+    expect(result.error).toContain('arduino_uno');
+    expect(result.error).toContain('insufficient RAM');
+  });
+
+  test('should allow List type in struct field on esp32', () => {
+    const source = `
+      @main
+      config {
+        board: esp32,
+        clock: 16MHz
+      }
+
+      struct DataPoint {
+        List values
+        int timestamp
+      }
+
+      on start {
+        print("test")
+      }
+    `;
+
+    const result = compile(source);
+    expect(result.success).toBe(true);
+  });
 });