public virtual LexemVariable Calculate(LexemFunction function)
{
if (this.OnFunctionCalculation != null)
return this.OnFunctionCalculation(function);
return null;
}
public static new LexemFunction Parse(ref string text)
{
if (String.IsNullOrWhiteSpace(text))
return null;
text = text.Trim();
Match match = Regex.Match(text, $"^(?<name>{FunctionNamePattern})\\s*\\(");
if (!match.Success)
return null;
var functionName = match.Groups["name"].Value;
if (String.IsNullOrEmpty(functionName))
return null;
int closeBracketIndex = text.Find(new char[] { ')' }, match.Value.Length, LexemBracket.Brackets);
if (closeBracketIndex < 0)
return null;
try
{
var result = new LexemFunction(text.Substring(0, closeBracketIndex + 1));
text = text.Crop(closeBracketIndex + 1);
return result;
}
catch
{
return null;
}
}
