/// <summary>
/// Evaluates a string expression of a function
/// </summary>
/// <param name="expression"></param>
/// <param name="handler">attach a custom function handler</param>
/// <returns>evauluated value</returns>
public static object Evaluate(string expression, AdditionalFunctionEventHandler handler)
{
FunctionEval expr = new FunctionEval(expression);
if (handler != null)
expr.AdditionalFunctionEventHandler += handler;
return expr.Evaluate();
}
/// <summary>
/// This routine will replace functions existing in the Expression property with thier respective values
/// </summary>
/// <returns>Expression string with all found functions replaced with returned values</returns>
public string Replace()
{
StringBuilder strbRet = new StringBuilder(Expression);
Match m = DefinedRegex.Function.Match(Expression);
while (m.Success)
{
int nDepth = 1;
int nIdx = m.Index + m.Length;
//Get the parameter string
while (nDepth > 0)
{
if (nIdx >= strbRet.Length)
throw new ArgumentException("Missing ')' in Expression");
if (strbRet[nIdx] == ')')
nDepth--;
if (strbRet[nIdx] == '(')
nDepth++;
nIdx++;
}
string expression = strbRet.ToString(m.Index, nIdx - m.Index);
FunctionEval eval = new FunctionEval(expression);
eval.AdditionalFunctionEventHandler += this.AdditionalFunctionEventHandler;
eval._variables = this._variables;
strbRet.Replace(expression, "" + eval.Evaluate());
m = DefinedRegex.Function.Match(strbRet.ToString());
}
//Replace Variable in the path!
m = DefinedRegex.Variable.Match(strbRet.ToString());
while (m.Success)
{
strbRet.Replace(m.Value, "" + _variables[m.Groups["Variable"].Value]);
m = DefinedRegex.Variable.Match(strbRet.ToString());
}
return strbRet.ToString();
}
/// <summary>
/// Evaluates a string expression of a function
/// </summary>
/// <param name="expression"></param>
/// <returns>evauluated value</returns>
public static object Evaluate(string expression)
{
FunctionEval expr = new FunctionEval(expression);
return expr.Evaluate();
}