public static EquationSegment SplitEquation(string equation, int splitIndex, SplitType sideToGet)
{
var retStruct = new EquationSegment();
char beginningBracket;
char endingBracket;
int increment;
int limitValue;
if (splitIndex == 0 && (sideToGet == SplitType.LeftSide || sideToGet == SplitType.ExponentLeft))
{
retStruct.EndIndex = 0;
retStruct.StartIndex = 0;
retStruct.Segment = "";
return(retStruct);
}
if (sideToGet == SplitType.LeftSide || sideToGet == SplitType.ExponentLeft)
{
beginningBracket = ')';
endingBracket = '(';
increment = -1;
limitValue = -1;
}
else
{
beginningBracket = '(';
endingBracket = ')';
increment = 1;
limitValue = equation.Count();
}
//the left side is enclosed with brackets, so the only way to terminate the left side is with an opening bracket
if (equation[splitIndex + increment] == beginningBracket)
{
int totalBrackets = 1;
int index = splitIndex + increment;
while (totalBrackets != 0)
{
index += increment;
if (index == limitValue)
{
throw new Exception("formatting error, brackets not set up properly");
}
if (equation[index] == beginningBracket)
{
totalBrackets++;
}
if (equation[index] == endingBracket)
{
totalBrackets--;
}
}
if (sideToGet == SplitType.LeftSide || sideToGet == SplitType.ExponentLeft)
{
retStruct.EndIndex = splitIndex;
retStruct.StartIndex = index;
retStruct.Segment = equation.Substring(retStruct.StartIndex, retStruct.EndIndex - retStruct.StartIndex);
}
else
{
retStruct.EndIndex = index + 1;
retStruct.StartIndex = splitIndex + 1;
retStruct.Segment = equation.Substring(retStruct.StartIndex, retStruct.EndIndex - retStruct.StartIndex);
}
return(retStruct);
}
else
{
//for this case, order of operations must be respected because of lack of brackets
//there are two ways for a termination to occur, either one of the terminating characters is reached
//or an unexpected endingbracket is reached, such as in the case (x/y)
int index = splitIndex + increment;
char[] terminatingChars = new char[0];
bool ignoreCharacterTermination = false;
bool ignoreBracketTermination = false;
if (sideToGet == SplitType.LeftSide)
{
terminatingChars = new[] { '=', '+', '-' };
}
if (sideToGet == SplitType.RightSide)
{
terminatingChars = new[] { '=', '+', '-', '*', '/' };
}
if (sideToGet == SplitType.ExponentRight)
{
terminatingChars = new[] { '=', '+', '-', '*', '/' };
if (equation[index] == beginningBracket) //this expression may be always false
{
ignoreCharacterTermination = true;
}
else
{
index++; //we want to completely ignore the first character because of negatives
ignoreBracketTermination = true;
}
}
if (sideToGet == SplitType.ExponentLeft)
{
terminatingChars = new[] { '=', '+', '-', '*', '/' };
}
int totalBrackets = 0;
if (index < equation.Count())
{
while (true)
{
//first try character based termination
if (terminatingChars.Contains(equation[index]))
{
if (!ignoreCharacterTermination)
{
break;
}
}
//now try bracket based termination
if (equation[index] == beginningBracket)
{
if (!ignoreBracketTermination)
{
totalBrackets++;
}
}
if (equation[index] == endingBracket)
{
if (!ignoreBracketTermination)
{
totalBrackets--;
}
}
if (totalBrackets < 0)
{
//index -= increment;
break;
}
//nothing interesting, loop again
if (index == limitValue - increment)
{
index += increment;
break;
}
//firstCharacterException = false;
index += increment;
}
}
if (sideToGet == SplitType.LeftSide || sideToGet == SplitType.ExponentLeft)
{
retStruct.EndIndex = splitIndex;
retStruct.StartIndex = index + 1;
retStruct.Segment = equation.Substring(retStruct.StartIndex, retStruct.EndIndex - retStruct.StartIndex);
}
else
{
retStruct.EndIndex = index;
retStruct.StartIndex = splitIndex + 1;
retStruct.Segment = equation.Substring(retStruct.StartIndex, retStruct.EndIndex - retStruct.StartIndex);
}
return(retStruct);
}
}
public static EquationSegment SplitEquation(string equation, int splitIndex, SplitType sideToGet)
{
var retStruct = new EquationSegment();
char beginningBracket;
char endingBracket;
int increment;
int limitValue;
if (splitIndex == 0 && (sideToGet == SplitType.LeftSide || sideToGet == SplitType.ExponentLeft)){
retStruct.EndIndex = 0;
retStruct.StartIndex = 0;
retStruct.Segment = "";
return retStruct;
}
if (sideToGet == SplitType.LeftSide || sideToGet == SplitType.ExponentLeft){
beginningBracket = ')';
endingBracket = '(';
increment = -1;
limitValue = -1;
}
else{
beginningBracket = '(';
endingBracket = ')';
increment = 1;
limitValue = equation.Count();
}
//the left side is enclosed with brackets, so the only way to terminate the left side is with an opening bracket
if (equation[splitIndex + increment] == beginningBracket){
int totalBrackets = 1;
int index = splitIndex + increment;
while (totalBrackets != 0){
index += increment;
if (index == limitValue)
throw new Exception("formatting error, brackets not set up properly");
if (equation[index] == beginningBracket){
totalBrackets++;
}
if (equation[index] == endingBracket){
totalBrackets--;
}
}
if (sideToGet == SplitType.LeftSide || sideToGet == SplitType.ExponentLeft){
retStruct.EndIndex = splitIndex;
retStruct.StartIndex = index;
retStruct.Segment = equation.Substring(retStruct.StartIndex, retStruct.EndIndex - retStruct.StartIndex);
}
else{
retStruct.EndIndex = index + 1;
retStruct.StartIndex = splitIndex + 1;
retStruct.Segment = equation.Substring(retStruct.StartIndex, retStruct.EndIndex - retStruct.StartIndex);
}
return retStruct;
}
else{
//for this case, order of operations must be respected because of lack of brackets
//there are two ways for a termination to occur, either one of the terminating characters is reached
//or an unexpected endingbracket is reached, such as in the case (x/y)
int index = splitIndex + increment;
char[] terminatingChars = new char[0];
bool ignoreCharacterTermination = false;
bool ignoreBracketTermination = false;
if (sideToGet == SplitType.LeftSide){
terminatingChars = new[]{'=', '+', '-'};
}
if (sideToGet == SplitType.RightSide){
terminatingChars = new[]{'=', '+', '-', '*', '/'};
}
if (sideToGet == SplitType.ExponentRight){
terminatingChars = new[]{'=', '+', '-', '*', '/'};
if (equation[index] == beginningBracket){ //this expression may be always false
ignoreCharacterTermination = true;
}
else{
index++; //we want to completely ignore the first character because of negatives
ignoreBracketTermination = true;
}
}
if (sideToGet == SplitType.ExponentLeft){
terminatingChars = new[]{'=', '+', '-', '*', '/'};
}
int totalBrackets = 0;
if (index < equation.Count()){
while (true){
//first try character based termination
if (terminatingChars.Contains(equation[index])){
if (!ignoreCharacterTermination){
break;
}
}
//now try bracket based termination
if (equation[index] == beginningBracket){
if (!ignoreBracketTermination){
totalBrackets++;
}
}
if (equation[index] == endingBracket){
if (!ignoreBracketTermination){
totalBrackets--;
}
}
if (totalBrackets < 0){
//index -= increment;
break;
}
//nothing interesting, loop again
if (index == limitValue - increment){
index += increment;
break;
}
//firstCharacterException = false;
index += increment;
}
}
if (sideToGet == SplitType.LeftSide || sideToGet == SplitType.ExponentLeft){
retStruct.EndIndex = splitIndex;
retStruct.StartIndex = index + 1;
retStruct.Segment = equation.Substring(retStruct.StartIndex, retStruct.EndIndex - retStruct.StartIndex);
}
else{
retStruct.EndIndex = index;
retStruct.StartIndex = splitIndex + 1;
retStruct.Segment = equation.Substring(retStruct.StartIndex, retStruct.EndIndex - retStruct.StartIndex);
}
return retStruct;
}
}