Add support for nested array literals and indexing in parser

src/parser/mod.rs

@@ -450,20 +450,20 @@ impl Parser {
     }
 
     fn parse_index(&mut self, array_name: String) -> Expression {
-        if let Some(Token::SquareLeft) = self.peek() {
+        let mut result = Expression::Identifier(array_name.clone());
+        while Some(&Token::SquareLeft) == self.peek() {
             self.advance(); // consume '['
             let index_expr = self.parse_first();
             match self.advance() {
                 Some(Token::SquareRight) => {}
                 _ => panic!("Expected ']' after array index"),
             }
-            Expression::Index {
-                array: Box::new(Expression::Identifier(array_name)),
+            result = Expression::Index {
+                array: Box::new(result),
                 index: Box::new(index_expr),
-            }
-        } else {
-            panic!("Expected '[' after identifier for array indexing");
+            };
         }
+        result
     }
 
     fn parse_array_literal(&mut self) -> Expression {

tests/integration_tests.rs

@@ -976,3 +976,46 @@ print arr;
     let out = run_rts(code);
     assert_eq!(out, "[1, 2, 3]");
 }
+
+// ========== Nested Arrays ==========
+
+#[test]
+fn test_nested_array_literal() {
+    let out = run_rts("let arr = [1, [2, 3]];\nprint arr[1];");
+    assert_eq!(out, "[2, 3]");
+}
+
+#[test]
+fn test_nested_array_index_depth_2() {
+    let out = run_rts("let arr = [[10, 20], [30, 40]];\nprint arr[1][0];");
+    assert_eq!(out, "30");
+}
+
+#[test]
+fn test_nested_array_index_depth_3() {
+    let out = run_rts("let x = [10, [3, [6, 11]], 5];\nprint x[1][1][0];");
+    assert_eq!(out, "6");
+}
+
+#[test]
+fn test_nested_array_index_first_element() {
+    let out = run_rts("let arr = [[1, 2], [3, 4]];\nprint arr[0][0];");
+    assert_eq!(out, "1");
+}
+
+#[test]
+fn test_nested_array_index_with_expression() {
+    let code = r#"
+let arr = [[10, 20], [30, 40]];
+let i = 1;
+print arr[i][i - 1];
+"#;
+    let out = run_rts(code);
+    assert_eq!(out, "30");
+}
+
+#[test]
+fn test_nested_array_print_whole() {
+    let out = run_rts("let arr = [[1, 2], [3, 4]];\nprint arr;");
+    assert_eq!(out, "[[1, 2], [3, 4]]");
+}