Add break continue

example.chun

@@ -34,6 +34,14 @@ print("List:", numbers);
 print("First element (index 0):", numbers[0]);
 print("Third element (index 2):", numbers[2]);
 
+for(number i = 0; i < len(numbers); i = i + 1) {
+    print("List element", numbers[i]);
+}
+
+while(true) {
+    print("test break");
+    break;
+}
 // Test maps
 print("\n=== Map Demo ===");
 map config = {"host": "localhost", "port": "8080"};

src/ast.h

@@ -183,6 +183,14 @@ struct ReturnStmt : public Stmt {
     explicit ReturnStmt(ExprPtr value = nullptr) : value(std::move(value)) {}
 };
 
+struct BreakStmt : public Stmt {
+    BreakStmt() = default;
+};
+
+struct ContinueStmt : public Stmt {
+    ContinueStmt() = default;
+};
+
 struct FunctionDecl : public Stmt {
     std::string name;
     std::vector<std::pair<std::string, std::string>> parameters; // (type, name)

src/interpreter.cpp

@@ -106,6 +106,10 @@ void Interpreter::execute_statement(const Stmt& stmt) {
         exec_for(*for_stmt);
     } else if (auto* return_stmt = dynamic_cast<const ReturnStmt*>(&stmt)) {
         exec_return(*return_stmt);
+    } else if (auto* break_stmt = dynamic_cast<const BreakStmt*>(&stmt)) {
+        exec_break(*break_stmt);
+    } else if (auto* continue_stmt = dynamic_cast<const ContinueStmt*>(&stmt)) {
+        exec_continue(*continue_stmt);
     } else if (auto* func_decl = dynamic_cast<const FunctionDecl*>(&stmt)) {
         exec_function_decl(*func_decl);
     } else if (auto* class_decl = dynamic_cast<const ClassDecl*>(&stmt)) {
@@ -397,8 +401,17 @@ void Interpreter::exec_if(const IfStmt& stmt) {
 }
 
 void Interpreter::exec_while(const WhileStmt& stmt) {
-    while (is_truthy(evaluate(*stmt.condition))) {
-        execute_statement(*stmt.body);
+    try {
+        while (is_truthy(evaluate(*stmt.condition))) {
+            try {
+                execute_statement(*stmt.body);
+            } catch (const ContinueException&) {
+                // Continue: just proceed to the next iteration (check condition again)
+                continue;
+            }
+        }
+    } catch (const BreakException&) {
+        // Break: exit the loop
     }
 }
 
@@ -412,12 +425,18 @@ void Interpreter::exec_for(const ForStmt& stmt) {
         }
         
         while (!stmt.condition || is_truthy(evaluate(*stmt.condition))) {
-            execute_statement(*stmt.body);
+            try {
+                execute_statement(*stmt.body);
+            } catch (const ContinueException&) {
+                // Continue: proceed to increment
+            }
             
             if (stmt.increment) {
                 evaluate(*stmt.increment);
             }
         }
+    } catch (const BreakException&) {
+        // Break: exit the loop
     } catch (...) {
         environment = previous;
         throw;
@@ -431,6 +450,14 @@ void Interpreter::exec_return(const ReturnStmt& stmt) {
     throw ReturnException(value);
 }
 
+void Interpreter::exec_break(const BreakStmt& stmt) {
+    throw BreakException();
+}
+
+void Interpreter::exec_continue(const ContinueStmt& stmt) {
+    throw ContinueException();
+}
+
 void Interpreter::exec_function_decl(const FunctionDecl& stmt) {
     auto func_decl = std::make_shared<FunctionDecl>(stmt);
     auto func = std::make_shared<FunctionValue>(stmt.name, func_decl);

src/interpreter.h

@@ -20,6 +20,9 @@ public:
     explicit ReturnException(ValuePtr value) : value(std::move(value)) {}
 };
 
+class BreakException : public std::exception {};
+class ContinueException : public std::exception {};
+
 class Environment {
 public:
     std::shared_ptr<Environment> parent;
@@ -138,6 +141,8 @@ private:
     void exec_while(const WhileStmt& stmt);
     void exec_for(const ForStmt& stmt);
     void exec_return(const ReturnStmt& stmt);
+    void exec_break(const BreakStmt& stmt);
+    void exec_continue(const ContinueStmt& stmt);
     void exec_function_decl(const FunctionDecl& stmt);
     void exec_class_decl(const ClassDecl& stmt);
     

src/lexer.cpp

@@ -224,6 +224,8 @@ TokenType Lexer::get_keyword_type(const std::string& text) const {
         {"and", TokenType::AND},
         {"or", TokenType::OR},
         {"this", TokenType::THIS},
+        {"continue", TokenType::CONTINUE},
+        {"break", TokenType::BREAK},
     };
     
     auto it = keywords.find(text);

src/lexer.h

@@ -12,7 +12,7 @@ enum class TokenType {
     // Keywords
     CLASS, FUNC, NUMBER, STRING, BOOL, LIST, MAP,
     IF, ELSE, WHILE, FOR, RETURN, VAR,
-    TRUE, FALSE, NIL, THIS,
+    TRUE, FALSE, NIL, THIS, CONTINUE, BREAK,
     
     // Operators
     PLUS, MINUS, STAR, SLASH, PERCENT,

src/parser.cpp

@@ -179,6 +179,8 @@ StmtPtr Parser::statement() {
     if (match({TokenType::WHILE})) return while_statement();
     if (match({TokenType::FOR})) return for_statement();
     if (match({TokenType::RETURN})) return return_statement();
+    if (match({TokenType::BREAK})) return break_statement();
+    if (match({TokenType::CONTINUE})) return continue_statement();
     if (match({TokenType::LEFT_BRACE})) return block_statement();
     
     return expression_statement();
@@ -247,6 +249,16 @@ StmtPtr Parser::return_statement() {
     return std::make_unique<ReturnStmt>(std::move(value));
 }
 
+StmtPtr Parser::break_statement() {
+    consume(TokenType::SEMICOLON, "Expected ';' after 'break'.");
+    return std::make_unique<BreakStmt>();
+}
+
+StmtPtr Parser::continue_statement() {
+    consume(TokenType::SEMICOLON, "Expected ';' after 'continue'.");
+    return std::make_unique<ContinueStmt>();
+}
+
 StmtPtr Parser::block_statement() {
     std::vector<StmtPtr> statements;
     

src/parser.h

@@ -44,6 +44,8 @@ private:
     StmtPtr while_statement();
     StmtPtr for_statement();
     StmtPtr return_statement();
+    StmtPtr break_statement();
+    StmtPtr continue_statement();
     StmtPtr block_statement();
     StmtPtr expression_statement();
     

tests/test_basic.cpp

@@ -148,3 +148,72 @@ TEST_CASE("interpreter performance: simple loop", "[perf][script]") {
         REQUIRE(r_num->value == 499500.0);
     };
 }
+
+TEST_CASE("loop break", "[script][loop]") {
+    State state;
+    const char* script = R"(
+        number sum = 0;
+        for (number i = 0; i < 10; i = i + 1) {
+            if (i == 5) {
+                break;
+            }
+            sum = sum + i;
+        }
+    )";
+
+    REQUIRE(state.do_string(script));
+    auto sum_val = state.get_global("sum");
+    REQUIRE(sum_val);
+    auto sum_num = std::dynamic_pointer_cast<NumberValue>(sum_val);
+    REQUIRE(sum_num->value == 10.0); // 0+1+2+3+4 = 10
+}
+
+TEST_CASE("loop continue", "[script][loop]") {
+    State state;
+    const char* script = R"(
+        number sum = 0;
+        for (number i = 0; i < 5; i = i + 1) {
+            if (i == 2) {
+                continue;
+            }
+            sum = sum + i;
+        }
+    )";
+
+    REQUIRE(state.do_string(script));
+    auto sum_val = state.get_global("sum");
+    REQUIRE(sum_val);
+    auto sum_num = std::dynamic_pointer_cast<NumberValue>(sum_val);
+    REQUIRE(sum_num->value == 8.0); // 0+1+3+4 = 8
+}
+
+TEST_CASE("while break and continue", "[script][loop]") {
+    State state;
+    const char* script = R"(
+        number i = 0;
+        number sum = 0;
+        while (i < 10) {
+            i = i + 1;
+            if (i == 3) {
+                continue;
+            }
+            if (i == 6) {
+                break;
+            }
+            sum = sum + i;
+        }
+    )";
+
+    REQUIRE(state.do_string(script));
+    auto sum_val = state.get_global("sum");
+    REQUIRE(sum_val);
+    auto sum_num = std::dynamic_pointer_cast<NumberValue>(sum_val);
+    REQUIRE(sum_num->value == 12.0); 
+    // 1st iter: i=1, sum=1
+    // 2nd iter: i=2, sum=1+2=3
+    // 3rd iter: i=3, continue
+    // 4th iter: i=4, sum=3+4=7
+    // 5th iter: i=5, sum=7+5=12
+    // 6th iter: i=6, break
+    // Result should be 12.0
+}