BlockNode* Parser::parseBlock(bool needBraces, const bool scoped/* = true */) {
if (needBraces) {
ensureToken(tLBRACE);
}
if (scoped) {
pushScope();
}
BlockNode* block = new BlockNode(_currentTokenIndex,
_currentScope);
TokenKind sentinel = needBraces ? tRBRACE : tEOF;
while (currentToken() != sentinel) {
if (currentToken() == tSEMICOLON) {
consumeToken();
continue;
}
AstNode* statement = parseStatement();
// Ignore statements that doesn't result in AST nodes, such
// as variable or function declaration.
if (statement != 0) {
block->add(statement);
}
}
if (scoped) {
popScope();
}
if (needBraces) {
ensureToken(tRBRACE);
}
return block;
}
FunctionNode* Parser::parseFunction() {
uint32_t tokenIndex = _currentTokenIndex;
ensureKeyword("function");
if (currentToken() != tIDENT) {
error("identifier expected");
}
const string& returnTypeName = currentTokenValue();
VarType returnType = nameToType(returnTypeName);
if (returnType == VT_INVALID) {
error("wrong return type");
}
consumeToken();
if (currentToken() != tIDENT) {
error("name expected");
}
const string& name = currentTokenValue();
consumeToken();
Signature signature;
signature.push_back(SignatureElement(returnType, "return"));
ensureToken(tLPAREN);
while (currentToken() != tRPAREN) {
const string& parameterTypeName = currentTokenValue();
VarType parameterType = nameToType(parameterTypeName);
if (parameterType == VT_INVALID) {
error("wrong parameter type");
}
consumeToken();
const string& parameterName = currentTokenValue();
if (currentToken() != tIDENT) {
error("identifier expected");
}
consumeToken();
signature.push_back(SignatureElement(parameterType, parameterName));
if (currentToken() == tCOMMA) {
consumeToken();
}
}
ensureToken(tRPAREN);
BlockNode* body = 0;
pushScope();
for (uint32_t i = 1; i < signature.size(); i++) {
const string& name = signature[i].second;
VarType type = signature[i].first;
if (!_currentScope->declareVariable(name, type)) {
error("Formal \"%s\" already declared", name.c_str());
}
}
if ((currentToken() == tIDENT) && currentTokenValue() == "native") {
consumeToken();
if (currentToken() != tSTRING) {
error("Native name expected, got %s", tokenStr(currentToken()));
}
pushScope();
body = new BlockNode(_currentTokenIndex, _currentScope);
body->add(new NativeCallNode(tokenIndex, currentTokenValue(), signature));
consumeToken();
ensureToken(tSEMICOLON);
body->add(new ReturnNode(0, 0));
popScope();
} else {
body = parseBlock(true, false);
if (body->nodes() == 0 ||
!(body->nodeAt(body->nodes() - 1)->isReturnNode())) {
body->add(new ReturnNode(0, defaultReturnExpr(returnType)));
}
}
popScope();
if (_currentScope->lookupFunction(name) != 0) {
error("Function %s already defined", name.c_str());
}
FunctionNode* result = new FunctionNode(tokenIndex, name, signature, body);
_currentScope->declareFunction(result);
// We don't add function node into AST.
return 0;
}