Esempio n. 1
0
//put crtOp on stack respecting operator precedence; i.e. * can be pushed on top of + or - but not the other way round
void putOperatorOnStack(char* crtOp, FILE* out)
{
	char name[20];
	char* topOp = topElement(&opStack);

	if (DEBUG) {printf("putOperatorOnStack(%s): crtOp = %s topOp = %s\n", D(crtOp), D(crtOp), D(topOp));}

	//BASE CASE: left paranthesis; push and resume
	if (!isOperator(topOp))
	{
		if (DEBUG) {printf("putOperatorOnStack(%s): OP_PUSH(%s)\n", D(crtOp), D(crtOp));}
		push(createVElement(crtOp), &opStack, -1);
		return;
	}

	int opPerformed = 0;
	while (isOperator(topOp))
	{
		//If the precedence of the operator which needs to be put on the stack crtOp is lower than the precedence of the operator
		//on the top of the stack, topOp, perform the operation denoted by topOp and the top two numbers from the RESULT_STACK.
		//An optimization step is performed by using the ACC, thus avoiding the need to create extra temporary variables.
		if (getPrecedence(crtOp) <= getPrecedence(topOp))
		{
			if (!opPerformed)
			{
				//in the very first iteration load number from RESULT_STACK into ACC
				VElement* temp = pop(&resStack);
				if (DEBUG) {printf("putOperatorOnStack(): RES_POP(%s)\n", D(temp->data));}
				fprintf(out, "\tLOAD\t%s\n", temp->data);
			}

			if (DEBUG) {printf("putOperatorOnStack(%s): getPrecedence(%s) <= getPrecedence(%s)\n", D(crtOp), D(crtOp), D(topOp));}
			//perform operation topOp between ACC and the number on the top of the RESULT_STACK
			performOperationWithACC(out);
			opPerformed = 1;
		}else{
			if (DEBUG) {printf("putOperatorOnStack(%s): getPrecedence(%s) > getPrecedence(%s)\n", D(crtOp), D(crtOp), D(topOp));}
			break;
		}
		//fetch next operand
		topOp = topElement(&opStack);
	}

	if (opPerformed)
	{
		//store result from ACC into temporary variable
		strcpy(name, newName(VAR));
		fprintf(out, "\tSTORE\t%s\n", name);
		if (DEBUG) {printf("putOperatorOnStack(): RES_PUSH(%s)\n", D(name));}
		push(createVElement(name), &resStack, -1);
	}

	if (DEBUG) {printf("putOperatorOnStack(%s): OP_PUSH(%s)\n", D(crtOp), D(crtOp));}
	push(createVElement(crtOp), &opStack, -1);
}
Esempio n. 2
0
//process all operators from the OPERATOR_STACK, going from top to the bottom  up to the first "(" operator or an empty stack, whichever comes first
void reduceParanthesis(FILE* out, int withLPar)
{
	char name[20];

	if (isStackEmpty(&opStack))
	{
		if (DEBUG) {printf("reduceParanthesis(): OP stack is empty\n");}
		return;
	}

	char* topOp = topElement(&opStack);
	if (!isOperator(topOp))
	{
		if (DEBUG) {printf("reduceParanthesis(): OP_POP(%s)\n", D(topOp));}
		pop(&opStack);
		return;
	}
	if (DEBUG) {printf("reduceParanthesis(): topOp = %s\n", D(topOp));}

	//1. take the number at the top of the RESULT_STACK
	VElement* temp = pop(&resStack);
	if (DEBUG) {printf("reduceParanthesis(): RES_POP(%s)\n", D(temp->data));}

	//2. load it into ACC
	fprintf(out, "\tLOAD\t%s\n", temp->data);
	while (isOperator(topOp))
	{
		if (DEBUG)
		{
			printf("reduceParanthesis(): OP stack is: \n"); displayStack(&opStack);
			printf("reduceParanthesis(): RES stack is: \n"); displayStack(&resStack);
		}

		//3. perform operation between ACC, number on top of RESULT_STACK using operator on top of OPERATOR_STACK; store result in ACC
		performOperationWithACC(out);

		topOp = topElement(&opStack);
	}//repeat until empty stack or "(" is encountered

	if (withLPar)
	{
		//remove left paranthesis and store ACC on RESULT_STACK
		strcpy(name, newName(VAR));
		fprintf(out, "\tSTORE\t%s\n", name);
		if (DEBUG) {printf("reduceParanthesis(): RES_PUSH(%s)\n", D(name));}

		push(createVElement(name), &resStack, -1);

		if (DEBUG) {printf("reduceParanthesis(): OP_POP(%s)\n", D(topOp));}

		pop(&opStack);
	}
}
Esempio n. 3
0
/************************ convertSubTaskOperator *******************************
void convertSubTaskOperator(Stack stack, Out out, Element *pElement)
Purpose:
    This function handles the case of an operator token.
    The operators in the stack with a higher or equal precedence get outted 
    and the new operator gets pushed to the stack.		
Parameters:
    I/O Stack stack	    The current stack.
    O Out out		    The out structure used in the conversion.
    I Element *pElement	    The operator element.
Returns:
    stack parm - the updated stack.
    out parm - the updated out structure.
Notes:
    This is a sub task of the query conversion from infix format to 
    postfix format.
*******************************************************************************/
void convertSubTaskOperator(Stack stack, Out out, Element *pElement)
{
    while(isEmpty(stack) == FALSE && pElement->iPrecedence <= topElement(stack).iPrecedence)
    //loop until the stack is empty or there's no more operator in the stack with a lower
    //precedence than the top of the stack 
    {
        addOut(out, pop(stack)); //POP and OUT the higher precedence operator from the stack
    }
    push(stack, *pElement);
}
Esempio n. 4
0
/*********************** convertSubTaskRemainingStack **************************
int convertSubTaskRemainingStack(Stack stack, Out out)
Purpose:
    This function handles the rest of the stack once we've gone through 
    all of the tokens in the input. It also handles the case of a leftover
    unmatched parenthesis in the stack.
Parameters:
    I/O Stack stack	The current stack.
    O Out out	        The out structure used in the conversion.
Returns:
    stack parm - the freed stack.
    out parm - the final out structure.
Notes:
    This is a sub task of the query conversion from infix format to 
    postfix format.
*******************************************************************************/
int convertSubTaskRemainingStack(Stack stack, Out out)
{
    while (isEmpty(stack) == FALSE)	//goes through the remaining stack until empty
    {
        if (topElement(stack).iCategory == CAT_LPAREN)//if an unmatched ( is found
  	{
  	    freeStack(stack); //at this point we are done using the stack
  	    return WARN_MISSING_RPAREN; //return error
  	}	
  	addOut(out, pop(stack)); //POP and OUT the stack
    }
    freeStack(stack); //at this point we are done using the stack		
}
Esempio n. 5
0
/************************** convertSubTaskRParen *******************************
int convertSubTaskRParen(Stack stack, Out out)
Purpose:
    This function handles the case of a right parenthesis token.
    The elements in the stack get outted until we find the matching 
    right parenthesis if there is one.
Parameters:
    I/O Stack stack	The current stack.
    O Out out		The out structure used in the conversion.
Returns:
    stack parm - the updated stack.
    out parm - the updated out structure.
Notes:
    This is a sub task of the query conversion from infix format to 
    postfix format.
*******************************************************************************/
int convertSubTaskRParen(Stack stack, Out out)
{
    while (isEmpty(stack) == FALSE && topElement(stack).iCategory != CAT_LPAREN)
    {
        addOut(out, pop(stack)); //POP and OUT content of the stack until left parenthesis is found
    }
    if (isEmpty(stack) == TRUE) //if we didn't find a (
    {
        freeStack(stack); //at this point we are done using the stack
  	return WARN_MISSING_LPAREN; //return error
    }
    pop(stack); //POP and get rid of (
}
Esempio n. 6
0
bool Regola::applyMetadata(QTreeWidget *tree, MetadataInfo *info)
{
    //---
    bool result = true;
    int operations = 0 ;
    // build a list of commands
    QList<PseudoAttribute*>updateDataList;
    QList<PseudoAttribute*>insertDataList;
    QList<PseudoAttribute*>deleteDataList;
    // populate the lists
    updateDataList  = info->manualAttributeListByCondition(true, true);
    insertDataList  = info->manualAttributeListByCondition(false, true);
    deleteDataList  = info->manualAttributeListByCondition(true, false);

    if((updateDataList.size() + insertDataList.size() + deleteDataList.size()) == 0) {
        return true ;
    }

    _undoStack.beginMacro(tr("Metadata"));
    // update in place
    foreach(PseudoAttribute * attr, updateDataList) {
        int row = attr->row();
        Element *metaElement = topElement(row);
        if((NULL == metaElement)
                || ((NULL != metaElement) && (metaElement->getType() != Element::ET_PROCESSING_INSTRUCTION)
                    && (metaElement->getPITarget() != MetadataInfo::QXMLEDIT_TARGET_PI))) {
            result = false ;
        } else {
            QString newData = attr->toStringComplete();
            UndoEditCommand *undoCommand = new UndoEditCommand(tree, this, metaElement->indexPath());
            undoCommand->setOriginalElement(metaElement);
            metaElement->setPIData(newData);
            metaElement->display(metaElement->getUI(), paintInfo);
            metaElement->markEdited();
            undoCommand->setModifiedElement(metaElement);
            operations++;
            _undoStack.push(undoCommand);
        }
    }