public MathParserTermResult Parse(string expression, int startPos)
{
var i = startPos;
var dotCount = 0;
while (i < expression.Length && (Char.IsDigit(expression[i]) || expression[i] == '.'))
{
if (expression[i] == '.')
{
dotCount++;
if (dotCount > 1)
{
throw new InvalidOperationException("Wrong number of dots in expression!");
}
}
i++;
}
var result = new MathParserTermResult
{
StartPos = startPos,
EndPos = i,
Term = expression.Substring(startPos, i - startPos),
TermType = TermType.Number
};
return(result);
}
public MathParserTermResult Parse(string expression, int startPos)
{
if (!IsOperator(expression[startPos]))
{
throw new InvalidOperationException($"{expression[startPos]} is not valid operator!");
}
var result = new MathParserTermResult
{
StartPos = startPos,
EndPos = startPos + 1,
Term = expression[startPos].ToString(),
TermType = TermType.Operator
};
return(result);
}
public MathParserTermResult Parse(string expression, int startPos)
{
var i = startPos;
var termType = TermType.Const;
int numberOfParams = 0;
MathParserTermResult internalTermResult = null;
while (i < expression.Length && Char.IsLetter(expression[i]))
{
i++;
}
if (i < expression.Length && expression[i] == '(')
{
var subParser = new SubExpressionTermParser(true);
internalTermResult = subParser.Parse(expression, i);
numberOfParams = subParser.NumberOfParameters;
termType = TermType.Function;
}
var term = expression.Substring(startPos, i - startPos);
var result = new ComplexMathParserResult
{
StartPos = startPos,
EndPos = internalTermResult != null ? internalTermResult.EndPos : i,
Term = term,
TermType = termType,
InternalTerm = internalTermResult,
NumberOfParams = numberOfParams
};
return(result);
}