private void SetOperator(FunctionTreeBuilder ec, IOperator op)
{
if (!ec.SetOperator(op))
{
throw new EmptyExpressionException(mInput, mPos);
}
}
private void SetExpression(FunctionTreeBuilder ec, Node expr)
{
if (!ec.SetExpression(expr))
{
throw new OperatorException(mInput, mPos);
}
}
private void HandleNumber(FunctionTreeBuilder ec)
{
bool point = mInput[mPos] == '.';
int begin = mPos++;
while (mPos < mInput.Length)
{
if (mInput[mPos] == '.')
{
if (point)
{
throw new SyntaxException(mInput, mPos);
}
point = true;
}
else if (!char.IsDigit(mInput[mPos]))
{
break;
}
mPos++;
}
mPos--;
if (mInput[mPos] == '.')
{
throw new SyntaxException(mInput, mPos);
}
double d = double.Parse(mInput.Substring(begin, mPos - begin + 1));
SetExpression(ec, Node.Number(d));
}
private Node GetResultExpression(FunctionTreeBuilder ec)
{
Node result = ec.GetResult();
if (result == null)
{
throw new EmptyExpressionException(mInput, mPos);
}
return(result);
}
private void HandleMinus(FunctionTreeBuilder ec)
{
if (ec.LeftIsEmpty())
{
SetOperator(ec, new OperatorNegate());
}
else
{
SetOperator(ec, new OperatorSubtract());
}
}
private Node Parse(bool bParentheses)
{
FunctionTreeBuilder ec = new FunctionTreeBuilder();
while (mPos < mInput.Length)
{
switch (mInput[mPos])
{
case ' ':
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
case '.':
HandleNumber(ec);
break;
case 'x':
case 'X':
SetExpression(ec, mParams.X);
break;
case 'y':
case 'Y':
SetExpression(ec, mParams.Y);
break;
case 'z':
case 'Z':
SetExpression(ec, mParams.Z);
break;
case 't':
case 'T':
SetExpression(ec, mParams.T);
break;
case '+':
SetOperator(ec, new OperatorAdd());
break;
case '-':
HandleMinus(ec);
break;
case '/':
SetOperator(ec, new OperatorDivide());
break;
case '*':
SetOperator(ec, new OperatorMultiply());
break;
case '^':
SetOperator(ec, new OperatorPower());
break;
case '(':
mPos++;
SetExpression(ec, Parse(true));
break;
case ')':
if (!bParentheses)
{
throw new ParenthesisException(mInput, mPos, Resources.Opening);
}
return(GetResultExpression(ec));
case 'c':
case 'C':
if (ConsumeWord("cos"))
{
ConsumeOpeningParenthesis();
SetExpression(ec, Node.Cos(Parse(true)));
}
else
{
throw new UnknownWordException(mInput, mPos);
}
break;
case 'e':
case 'E':
if (ConsumeWord("exp"))
{
ConsumeOpeningParenthesis();
SetExpression(ec, Node.Exp(Parse(true)));
}
else
{
SetExpression(ec, Node.E());
}
break;
case 'l':
case 'L':
if (ConsumeWord("ln"))
{
ConsumeOpeningParenthesis();
SetExpression(ec, Node.Ln(Parse(true)));
}
else
{
throw new UnknownWordException(mInput, mPos);
}
break;
case 'p':
case 'P':
if (ConsumeWord("pi"))
{
SetExpression(ec, Node.PI());
}
else
{
throw new UnknownWordException(mInput, mPos);
}
break;
case 's':
case 'S':
if (ConsumeWord("sin"))
{
ConsumeOpeningParenthesis();
SetExpression(ec, Node.Sin(Parse(true)));
}
else if (ConsumeWord("sqrt"))
{
ConsumeOpeningParenthesis();
SetExpression(ec, Node.Sqrt(Parse(true)));
}
else
{
throw new UnknownWordException(mInput, mPos);
}
break;
default:
throw new UnknownTokenException(mInput, mPos);
}
mPos++;
}
if (bParentheses)
{
throw new ParenthesisException(mInput, mPos, Resources.Closing);
}
return(GetResultExpression(ec));
}
