support void functions

src/banana_test.cpp

@@ -139,6 +139,10 @@ TEST(Function, NoParameters) {
   EXPECT_EQ("true\n", exe("int sayHello() { print true; return 1; } sayHello();"));
 }
 
+TEST(Function, Void) {
+  EXPECT_EQ("true\n", exe("void hello() { print true; } hello();"));
+}
+
 TEST(Function, ParametersConversion) {
   EXPECT_EQ("11\n", exe("long add(long x, long y) { return x + y; } int x = add(5, 6); print x;"));
   EXPECT_EQ("A\n", exe("long num() { return 65; } char z = num(); print z;"));

src/lib/ast.cpp

@@ -280,21 +280,23 @@ FunctionNode::FunctionNode(const bool& is_main) : AbstractSyntaxTree() {
 }
 
 void FunctionNode::write(std::vector<const Instruction*>& instructions) {
-    JumpInstruction* jump = nullptr;
-    if (!is_main) {
-        jump = new JumpInstruction();
-        instructions.push_back(jump);
+    if (is_main) {
+        AbstractSyntaxTree::write(instructions);
+        for (auto parameter : parameters) {
+            instructions.push_back(new StoreInstruction(parameter->get_address()));
+        }
+        body->write(instructions);
+        return;
     }
-
+    JumpInstruction* jump = jump = new JumpInstruction();
+    instructions.push_back(jump);
     AbstractSyntaxTree::write(instructions);
     for (auto parameter : parameters) {
         instructions.push_back(new StoreInstruction(parameter->get_address()));
     }
     body->write(instructions);
-
-    if (!is_main) {
-        jump->set_address(ast::count_bytes(instructions));
-    }
+    instructions.push_back(new RetInstruction(0));
+    jump->set_address(ast::count_bytes(instructions));
 }
 
 std::vector<std::shared_ptr<const VariableNode>> FunctionNode::get_parameters() const {

src/lib/ast.h

@@ -32,7 +32,7 @@ class LiteralNode: public AbstractSyntaxTree {
 
 namespace ast {
 enum AstVarType {
-    BOOL, CHAR, INT, LONG,
+    BOOL, CHAR, INT, LONG, VOID
 };
 }
 

src/lib/parser.cpp

@@ -34,6 +34,7 @@ const std::map<TokenType, ast::AstVarType> TOKEN_TO_AST = {
     {TOKEN_CHAR, ast::CHAR},
     {TOKEN_INT, ast::INT},
     {TOKEN_LONG, ast::LONG},
+    {TOKEN_VOID, ast::VOID},
 };
 
 const std::map<ast::AstVarType, TokenType> AST_TO_TOKEN = maputils::reverse(TOKEN_TO_AST);
@@ -42,11 +43,16 @@ const std::set<TokenType> TYPES = {
     TOKEN_BOOL, TOKEN_CHAR, TOKEN_INT, TOKEN_LONG
 };
 
+const std::set<TokenType> RETURN_TYPES = {
+    TOKEN_BOOL, TOKEN_CHAR, TOKEN_INT, TOKEN_LONG, TOKEN_VOID
+};
+
 const std::map<TokenType, std::string> TYPE_NAME = {
     {TOKEN_BOOL, "bool"},
     {TOKEN_CHAR, "char"},
     {TOKEN_INT, "int"},
     {TOKEN_LONG, "long"},
+    {TOKEN_VOID, "void"},
 };
 
 const std::map<cinterface::ArgType, std::string> C_TYPE_NAME = {
@@ -61,6 +67,7 @@ const std::map<ast::AstVarType, std::string> AST_TYPE_NAME = {
     {ast::CHAR, "char"},
     {ast::INT, "int"},
     {ast::LONG, "long"},
+    {ast::VOID, "void"},
 };
 
 const std::map<cinterface::ArgType, ast::AstVarType> C_TYPE_TO_AST_TYPE = {
@@ -642,7 +649,7 @@ std::shared_ptr<AbstractSyntaxTree> statement(Parser& parser) {
     if (match_sequence(parser, {TYPES, {TOKEN_IDENTIFIER}, {TOKEN_EQUAL}})) {
         return var_statement(parser, previous(parser, 3), previous(parser, 2));
     }
-    if (match_sequence(parser, {TYPES, {TOKEN_IDENTIFIER}, {TOKEN_LEFT_PAREN}})) {
+    if (match_sequence(parser, {RETURN_TYPES, {TOKEN_IDENTIFIER}, {TOKEN_LEFT_PAREN}})) {
         return fun_statement(parser, previous(parser, 3), previous(parser, 2));
     }
     if (match_sequence(parser, {{TOKEN_IDENTIFIER}, {TOKEN_LEFT_PAREN}})) {

src/lib/scanner.cpp

@@ -374,6 +374,15 @@ std::vector<Token> scanner::scan(const std::string& code) {
                     tokens.push_back(create_token(TOKEN_IDENTIFIER, scanner));
                 }
                 break;
+            case 'v':
+                if (match_string(scanner, "void", /* keyword */ true)) {
+                    scanner.current += 4;
+                    tokens.push_back(create_token(TOKEN_VOID, scanner));
+                } else {
+                    scanner.current = match_identifier(scanner);
+                    tokens.push_back(create_token(TOKEN_IDENTIFIER, scanner));
+                }
+                break;
             case '"': {
                 int quote = match_quote(scanner);
                 if (quote == -1) {

src/lib/scanner.h

@@ -29,7 +29,7 @@ enum TokenType {
     TOKEN_RETURN, TOKEN_IF, TOKEN_ELSE, TOKEN_FOR,
     TOKEN_WHILE, TOKEN_AND, TOKEN_OR, TOKEN_PRINT,
     TOKEN_BOOL, TOKEN_CHAR, TOKEN_INT, TOKEN_LONG, 
-    TOKEN_TRUE, TOKEN_FALSE, TOKEN_AT_NATIVE
+    TOKEN_TRUE, TOKEN_FALSE, TOKEN_VOID, TOKEN_AT_NATIVE
 };
 
 struct Token{