Token *Parser::parse(bool *ok, QString *err, Token *token) const
{
if (mtokens.isEmpty())
return bRet(ok, true, err, QString(), token, Token(), new Token(Token::Program_Token));
TokenStack stack;
int i = 0;
while (true) {
if (mtokens.size() == i) {
stack.freeAll();
return bRet(ok, false, err, tr("Unexpected end of token list", "error"), token, Token(), (Token *) 0);
}
const Token &t = mtokens.at(i);
int x = 0;
ShiftReduceChoice choice = chooseShiftReduce(stack.state(), t.type(), &x);
switch (choice) {
case StateChangeChoice: {
stack.append(new Token(t), x);
++i;
break;
}
case ReduceChoice: {
bool b = false;
Token *nt = reduce(stack, x, &b, err);
if (!b) {
delete nt;
stack.freeAll();
return bRet(ok, b, token, t, (Token *) 0);
}
if (nt->type() == Token::Program_Token && stack.isEmpty()) {
if (i < mtokens.size() - 1)
return bRet(ok, false, err, tr("Unexpected error", "error"), token, t, (Token *) 0);
return bRet(ok, true, err, QString(), token, Token(), nt);
}
choice = chooseShiftReduce(stack.state(), nt->type(), &x);
if (ShiftChoice != choice)
return bRet(ok, false, err, tr("Failed to find shift rule", "error"), token, t, (Token *) 0);
stack.append(nt, x);
break;
}
case ShiftChoice: {
stack.freeAll();
return bRet(ok, false, err, tr("Unexpected shift rule", "error"), token, t, (Token *) 0);
}
case ErrorChoice:
default: {
stack.freeAll();
return bRet(ok, false, err, tr("Failed to find shift or reduce rule", "error"), token, t, (Token *) 0);
}
}
}
return bRet(ok, false, err, tr("Failed to finish parsing", "error"), token, Token(), (Token *) 0);
}
// LET command translate function
TokenStatus letTranslate(Translator &translator, Token *commandToken,
Token *&token)
{
TokenStatus status;
int column;
bool hidden;
DataType dataType;
bool done;
TokenStack letStack;
bool haveSubStr = false;
if (commandToken == NULL)
{
column = token->column();
hidden = true;
}
else // delete unneeded command token and get another token
{
column = commandToken->column();
delete commandToken;
hidden = false;
}
dataType = Any_DataType;
do
{
if ((status = translator.getOperand(token, dataType,
Translator::All_Reference)) != Good_TokenStatus)
{
if (token->column() > column)
{
return status;
}
// next token determines error
Token *nextToken;
if ((status = translator.getToken(nextToken)) != Good_TokenStatus)
{
status = ExpCmd_TokenStatus;
}
if (nextToken->isCode(Comma_Code) || nextToken->isCode(Eq_Code))
{
status = ExpAssignItem_TokenStatus;
}
else
{
status = ExpCmd_TokenStatus;
}
delete nextToken;
return status;
}
// get and check next token for comma or equal
status = translator.getToken(token);
if (token->isCode(Comma_Code))
{
done = false;
}
else if (token->isCode(Eq_Code))
{
done = true;
}
else // invalid token or parser error
{
if (translator.table().hasFlag(translator.doneStackTopToken(),
SubStr_Flag))
{
delete translator.doneStackPop();
}
return ExpEqualOrComma_TokenStatus;
}
// check if this is a sub-string assignment
if (translator.table().hasFlag(translator.doneStackTopToken(),
SubStr_Flag))
{
// delete comma/equal token, use sub-string function token
delete token;
// get sub-string function token from rpn item on top of stack
// (delete rpn item since it was not appended to output)
RpnItem *rpnItem = translator.doneStackPop();
token = rpnItem->token();
rpnItem->setToken(NULL); // prevent delete of token
delete rpnItem;
// change to assign sub-string code (first associated code)
translator.table().setToken(token,
translator.table().associatedCode(token->code()));
haveSubStr = true;
}
else // use comma/equal token
{
// change token to appropriate assign code
translator.table().setToken(token, Assign_Code);
status = translator.processDoneStackTop(token);
if (status != Good_TokenStatus)
{
return status;
}
}
letStack.push(token); // save token
// get data type for assignment
if (dataType == Any_DataType)
{
dataType = token->dataType();
}
token = NULL;
}
while (!done);
// get expression for value to assign
if ((status = translator.getExpression(token,
translator.equivalentDataType(dataType))) != Done_TokenStatus)
{
if (status == Parser_TokenStatus && token->isDataType(None_DataType))
{
status = ExpOpOrEnd_TokenStatus;
}
return status;
}
Token *letToken = letStack.pop();
if (!letStack.isEmpty())
{
if (haveSubStr)
{
// add each token saved in let stack except the last
do
{
// change to keep code (second associated code)
translator.table().setToken(letToken,
translator.table().associatedCode(letToken->code()));
// append to output and pop next token from let stack
translator.outputAppend(letToken);
letToken = letStack.pop();
}
while (!letStack.isEmpty()); // continue until last token
}
else // have a multiple assignment, change to list code
{
translator.table().setToken(letToken,
translator.table().secondAssociatedCode(letToken->code()));
}
}
// drop expresion result from done stack, append last assignment token
translator.doneStackDrop();
translator.outputAppend(letToken);
// set hidden LET flag if needed
if (!hidden)
{
letToken->addSubCode(Option_SubCode);
}
// check terminating token for end-of-statement
if (!translator.table().hasFlag(token, EndStmt_Flag))
{
return ExpOpOrEnd_TokenStatus;
}
return Done_TokenStatus;
}
