void ExprParser::close()
{
while (getOperator()!='(')
pop();
popOperator();
}
ParseStatus Parser::popDelimiter(TokenValue t) {
// Apply all pending operators until we hit the matching paren.
while (op_stack.back() != t) {
popOperator();
}
// Remove the matching paren from the operator stack.
op_stack.pop();
return PARSE_OK;
}
void ExprParser::pop()
{
char op = getOperator();
switch (op)
{
case 'm':
Generator::negate (mCode, getOperandType());
popOperator();
break;
case '+':
Generator::add (mCode, getOperandType (1), getOperandType());
popOperator();
replaceBinaryOperands();
break;
case '-':
Generator::sub (mCode, getOperandType (1), getOperandType());
popOperator();
replaceBinaryOperands();
break;
case '*':
Generator::mul (mCode, getOperandType (1), getOperandType());
popOperator();
replaceBinaryOperands();
break;
case '/':
Generator::div (mCode, getOperandType (1), getOperandType());
popOperator();
replaceBinaryOperands();
break;
case 'e':
case 'n':
case 'l':
case 'L':
case 'g':
case 'G':
Generator::compare (mCode, op, getOperandType (1), getOperandType());
popOperator();
popOperand();
popOperand();
mOperands.push_back ('l');
break;
default:
throw std::logic_error ("unknown operator");
}
}
ParseStatus Parser::pushOperator(Token& t) {
assert(t.isOperator());
// check priority
while(!op_stack.empty() &&
(getPriority(op_stack.back()) >= getPriority(t))) {
popOperator();
}
op_stack.push(t);
return PARSE_OK;
}
void ExprEvaluator::E() {
P();
tokenizer.nextToken();
while(tokenizer.isBinary()) {
pushOperator(binary(tokenizer.nextToken()));
tokenizer.consumeToken();
P();
tokenizer.nextToken();
}
while(operators.back() != oper::SANTINEL)
popOperator();
}
void convertToPostfix(char *str){
/* o1: Holds the precedence of the new operator
* o2: Holds the precendence of the topmost operator on the stack
* ptoken: The pointer to the start of each string delimited by commas
* stringToAdd: Houses a single character so strcat() can add singular characters
* aCopy: A copy of the given string used to read from as we are modifying the original string
*/
int o1, o2;
char *ptoken, stringToAdd[] = "0", aCopy[100];
/* Copy the given string to a second string to be read from */
strcpy(aCopy, str);
/* Set the first element of the given string to NULL, effectively erasing the string from the point of view of strcat() */
*str = '\0';
/* Cycle through each group of characters delimited by a whitespace */
for(ptoken = strtok(aCopy," "); ptoken != NULL; ptoken = strtok(NULL, " ")){
/* If the character is a bracket or operator, then run this code */
if(isOperator(*ptoken) && strlen(ptoken) == 1){
/* Code to figure out precedences of operators */
if(*ptoken == '*' || *ptoken == '/') o1 = 3;
else if(*ptoken == '^') o1 = 4;
else if(*ptoken == '+' || *ptoken == '-' ) o1 = 2;
if(seeOperator() == '*' || seeOperator() == '/') o2 = 3;
else if(seeOperator() == '^') o2 = 4;
else if(seeOperator() == '+' || seeOperator() == '-' ) o2 = 2;
else o2 = 0;
/* If the operator stack isn't empty, and the precedence of the new operator is less than or equal to the top operator
* in the stack, then pop the top operator in to the post-fix string, and push the new operator in to the stack.
*/
if(emptyOperator() != 1 && o1 <= o2){
*stringToAdd = popOperator();
strcat(str," ");
strcat(str,stringToAdd);
pushOperator(*ptoken);
}
/* Otherwise, if it's empty or the new operator has greater precedence, push to the operator stack */
else{
pushOperator(*ptoken);
}
}
/* If the character is a left bracket, push it into the operator stack */
else if(*ptoken == '('){
pushOperator(*ptoken);
}
/* If the character is a right bracket, pop operators off until you reach a left bracket, then pop off the left bracket without
* adding it to the string
*/
else if(*ptoken == ')'){
while(seeOperator() != '('){
*stringToAdd = popOperator();
strcat(str," ");
strcat(str, stringToAdd);
}
popOperator();
}
/* Otherwise(i.e. the string is a operand), just catenate the operand to the end of the string */
else{
strcat(str, " ");
strcat(str, ptoken);
}
}
/* Check if the operator stack is empty, if it isn't, add the top most operator to the end of the string, repeat until
* stack is empty.
* If the character is a bracket, then just pop it and don't add to the string.
*/
while(emptyOperator() == FALSE){
if(seeOperator() == '(' || seeOperator() == ')') popOperator();
else{
*stringToAdd = popOperator();
strcat(str," ");
strcat(str, stringToAdd);
}
}
}
void ExprEvaluator::pushOperator(oper o) {
while(isHigherPriority(operators.back(), o))
popOperator();
operators.push_back(o);
}
int buildTree(command_t commList, int i, int rootListIndex, int* rootList)
{
int maxOperandSize = 100;
int maxOperatorSize = 100;
int operandIndex = 0; // first empty index in operand stack
int operatorIndex = 0; // first empty index in operator stack
//printf("rootListIndex: %d\n", rootListIndex);
int* operatorList = malloc(sizeof(int)*maxOperatorSize);
int* operandList = malloc(sizeof(int)*maxOperandSize);
int returnIndex = -1;
//int i;
//printf("# of commands: %d\n", g_commandListLength);
for(; i < g_commandListLength; i++)
{
// printf("ii: %d\n", i);
//printf("p..operatorIndex: %d\n", operatorIndex);
//printf("p..operandIndex: %d\n", operandIndex);
if(operandIndex == maxOperandSize)
{
maxOperandSize *= 2;
operandList = realloc(operandList, sizeof(int)*maxOperandSize);
}
else if(operatorIndex == maxOperatorSize)
{
maxOperatorSize *= 2;
operatorList = realloc(operatorList, sizeof(int)*maxOperatorSize);
}
else if(commList[i].type == SIMPLE_COMMAND)
{
//printf("simple command\n");
//printf("operandIndex: %d\n", operandIndex);
operandList[operandIndex] = i;
operandIndex++;
// printStack(operatorIndex-1, operandIndex-1, operatorList, operandList);
continue;
}
else if(commList[i].type == OPEN_PAREN)
{
// push onto operator stack
operatorList[operatorIndex] = i;
operatorIndex++;
continue;
}
else if(commList[i].type == CLOSED_PAREN)
{
// pop off until reach open paren
int topIndex = operatorList[operatorIndex-1];
enum command_type top = commList[topIndex].type-1;
while(top != OPEN_PAREN)
{
//printf("pop til open paren \n");
popOperator(operatorIndex-1, operandIndex-1, operatorList, operandList, commList);
operandIndex--;
operatorIndex--;
//printStack(operatorIndex-1, operandIndex-1, operatorList, operandList);
// print stack for debugging
//printf("topIndex: %d\n", topIndex);
topIndex = operatorList[operatorIndex-1];
top = commList[topIndex].type;
}
//end loop: top = OPEN_PAREN
//printf("end paren popping\n");
int subShellIndex = operatorList[operatorIndex-1];
setSubShell(subShellIndex, operandIndex-1, operandList, commList);
operatorIndex--;
//printCommandList(commList, g_commandListLength);
//printStack(operatorIndex-1, operandIndex-1, operatorList, operandList);
continue;
}
else if(commList[i].type == NEW_LINE)
{
returnIndex = i;
if(i+1 == g_commandListLength)
{
// printf("return\n");
returnIndex = -1;
}
break;
}
else if(commList[i].type == IGNORE_COMMAND)
{
continue;
}
/*else if(commList[i].type == SEQUENCE_COMMAND)
{
//printf("i: %d\n", i);
returnIndex = i;
if(i == g_commandListLength-2 && commList[i+1].type == NEW_LINE)
{
returnIndex = -1;
}
break;
}*/
else
{
enum command_type input = commList[i].type;
if(operatorIndex == 0)
{
operatorList[0] = i;
operatorIndex++;
//printStack(operatorIndex-1, operandIndex-1, operatorList, operandList);
continue;
}
int topIndex = operatorIndex-1;
enum command_type top = commList[operatorList[topIndex]].type;
/* printf("topIndex: %d\n", topIndex);
printf("top: ");
printCommandType(top);
printf("input: ");
printCommandType(input);*/
while(checkPrecedence(input, top) && operatorIndex > 0)
{
// printf("PRECEDENCE\n");
// printf("stack1:\n");
//printStack(operatorIndex-1, operandIndex-1, operatorList, operandList);
popOperator(operatorIndex-1, operandIndex-1, operatorList, operandList, commList);
operandIndex--;
operatorIndex--;
// printf("stack2:\n");
//printStack(operatorIndex-1, operandIndex-1, operatorList, operandList);
//printf("op index: %d\n", operatorIndex);
// print stack for debugging
topIndex = operatorList[operatorIndex-1];
top = commList[topIndex].type;
/* printf("in loop topIndex: %d\n", topIndex);
printf("in loop top: ");
printCommandType(top);
printf("in loop input: ");
printCommandType(input);*/
}
operatorList[operatorIndex] = i;
operatorIndex++;
}
}
while(operatorIndex > 0)
{
popOperator(operatorIndex-1, operandIndex-1, operatorList, operandList, commList);
operandIndex--;
operatorIndex--;
// printf("stack3:\n");
// printStack(operatorIndex-1, operandIndex-1, operatorList, operandList);
}
free(operatorList);
free(operandList);
rootList[rootListIndex] = operandList[0];
return returnIndex;
}
ParseStatus Parser::emitEval() {
while(op_stack.size()) {
popOperator();
}
return PARSE_OK;
}
