/// <summary>
/// Initializes a new instance of the <see cref="MathEvaluator"/> class.
/// </summary>
public MathEvaluator()
{
_variables = new VariableDictionary(this);
_innerFunctions = new List <string>(FunctionExpression.GetFunctionNames());
_functions = new ReadOnlyCollection <string>(_innerFunctions);
_expressionCache = new Dictionary <string, IExpression>(StringComparer.OrdinalIgnoreCase);
_symbolStack = new Stack <string>();
_expressionQueue = new Queue <IExpression>();
_buffer = new StringBuilder();
_calculationStack = new Stack <double>();
_parameters = new Stack <double>(2);
}
private bool TryEndGroup(char c)
{
if (c != ')')
{
return(false);
}
bool hasStart = false;
while (_symbolStack.Count > 0)
{
string p = _symbolStack.Pop();
if (p == "(")
{
hasStart = true;
if (_symbolStack.Count == 0)
{
break;
}
string n = _symbolStack.Peek();
if (FunctionExpression.IsFunction(n))
{
p = _symbolStack.Pop();
IExpression f = GetExpressionFromSymbol(p);
_expressionQueue.Enqueue(f);
}
break;
}
IExpression e = GetExpressionFromSymbol(p);
_expressionQueue.Enqueue(e);
}
if (!hasStart)
{
throw new ParseException(Resources.UnbalancedParentheses);
}
return(true);
}
private IExpression GetExpressionFromSymbol(string p)
{
IExpression e;
if (_expressionCache.ContainsKey(p))
e = _expressionCache[p];
else if (OperatorExpression.IsSymbol(p))
{
e = new OperatorExpression(p);
_expressionCache.Add(p, e);
}
else if (FunctionExpression.IsFunction(p))
{
e = new FunctionExpression(p, false);
_expressionCache.Add(p, e);
}
else if (ConvertExpression.IsConvertExpression(p))
{
e = new ConvertExpression(p);
_expressionCache.Add(p, e);
}
else
throw new ParseException(Resources.InvalidSymbolOnStack + p);
return e;
}
