// Standard evaluation for single value.
private static bool evaluateSingle(Bracket b)
{
if (b == null)
{
return(false);
}
if (!b.Valid)
{
return(false);
}
if (b.contains(LIST_SEPARATOR.ToString()))
{
return(false);
}
return(true);
}
public override object calculate(Bracket b)
{
if (evaluate(b))
{
if (b.contains(LIST_SEPARATOR.ToString().Trim()))
{
double a = convertToNumber(b.Childs[0]);
double newBase = convertToNumber(b.Childs[2]);
return(Math.Log(a, newBase));
}
else
{
double a = convertToNumber(b.Childs[0]);;
return(Math.Log(a));
}
}
return(null);
}
public override bool evaluate(Bracket b)
{
if (evaluateSingle(b))
{
if (b.contains(UNLIMITED_VALUE))
{
return(false);
}
return(true);
}
else
{
if (b.contains(LIST_SEPARATOR.ToString()))
{
if (b.Childs.Length == 3)
{
return(b.contains(UNLIMITED_VALUE.ToString().Trim()));
}
return(false);
}
}
return(false);
}
/// <summary>
/// Parses a string that conatins the formula of a bracket.
/// </summary>
/// <param name="value">A string value represent the formula of the bracket.</param>
/// <param name="start">Starting index where the formula will be parsed.</param>
/// <returns>Returns the zero-based index where the bracket is closed within the formula.</returns>
public int parseString(string value, int start)
{
int i = start;
_openIndex = start - 1;
bool quit = false;
_childs.Clear();
_valid = true;
string strNode = "";
while (!quit)
{
if (value[i] == '(')
{
Bracket child = new Bracket(this);
i = child.parseString(value, i + 1);
if (strNode != "")
{
if (OPERATORS.Contains(strNode.Trim()))
{
// The last node was an operator.
_childs.Add(strNode.Trim());
}
else if (strNode == "~")
{
// The last node was the unlimited number sign.
_childs.Add(strNode.Trim());
}
else if (isNumber(strNode))
{
// The last node was a number.
_childs.Add(strNode.Trim());
}
else
{
if (strNode[strNode.Length - 1] == '%')
{
// Check if the last node was a percentage number.
if (!isNumber(strNode.Substring(0, strNode.Length - 1)))
{
_valid = false;
}
_childs.Add(strNode);
}
else
{
// Check if the last node was a code of registered function's code.
// Build up functions.
bool found = false;
foreach (CalcFunction fx in _builtin_functions)
{
if (fx.evaluateCode(strNode))
{
child.Function = fx;
found = true;
break;
}
}
if (!found)
{
// User defined functions.
foreach (CalcFunction fx in CalcFunctions.UserFunctions)
{
if (fx.evaluateCode(strNode))
{
child.Function = fx;
found = true;
break;
}
}
}
if (!found)
{
// No functions were found.
_valid = false;
_childs.Add(strNode);
}
}
}
}
_childs.Add(child);
strNode = "";
}
else
{
if (value[i] == ')')
{
quit = true;
_closeIndex = i;
}
else
{
if (OPERATORS.Contains(value[i].ToString().Trim()))
{
if (_childs.Count == 0)
{
if (value[i] != '-' && strNode == "")
{
_valid = false;
}
}
else
{
if (strNode == LIST_SEPARATOR.ToString().Trim() && value[i] != '-')
{
_valid = false;
}
}
if (strNode != "")
{
_childs.Add(strNode);
}
strNode = value[i].ToString().Trim();
}
else
{
if (strNode == "~")
{
_childs.Add(strNode);
strNode = "";
}
if (value[i] == '.' || (value[i] >= 48 && value[i] <= 57) ||
(value[i] >= 65 && value[i] <= 90) || (value[i] >= 97 && value[i] <= 122) ||
value[i] == '_' || value[i] == '%')
{
if (OPERATORS.Contains(strNode) && strNode != "")
{
if (_childs.Count > 0)
{
_childs.Add(strNode);
strNode = "";
}
}
strNode += value[i];
}
else if (value[i] == LIST_SEPARATOR)
{
if (strNode != "")
{
_childs.Add(strNode);
}
else if (_childs.Count == 0)
{
_valid = false;
}
strNode = LIST_SEPARATOR.ToString().Trim();
}
else if (value[i] == ' ')
{
if (strNode != "")
{
_childs.Add(strNode);
}
strNode = "";
}
else if (value[i] == UNLIMITED_VALUE)
{
if (strNode != "")
{
_childs.Add(strNode);
}
strNode = "~";
}
}
}
}
i++;
if (i >= value.Length)
{
quit = true;
}
}
if (strNode != "")
{
_childs.Add(strNode);
}
return(i);
}