/// <summary>
///
/// Cast the splitted string into a list of integers and operators.
/// </summary>
protected bool castElements()
{
IList <Object> expression = new List <Object>();
foreach (String str in splitedexpression)
{
if (str.Length == 0)
{
continue; // Skip empty string.
}
bool isinteger = Regex.IsMatch(str, @"\d+") && str.Length < 13;
bool OptOrParen = str.Length == 1
&&
(
OPERATORSlist.Contains((char)str.ElementAt(0)) ||
(char)str.ElementAt(0) == '(' || (char)str.ElementAt(0) == ')'
);
if (isinteger)
{
expression.Add(Int64.Parse(str));
}
else if (OptOrParen)
{
expression.Add(str.ElementAt(0));
}
else
{
return(false); // something is wrong is this line is executed.
}
}
this.castplistedexpression = expression;
return(true);
}
protected bool checkNumberAndOperator()
{
Int32 sum = 1;
foreach (char c in this.sourceexpression)
{
if (c <= '9' || c >= '0')
{
sum++; //add one if this is a number.
}
else if (OPERATORSlist.Contains(c))
{
sum--; //else minus one if this is a operator.
}
else
{
sum = 1; //else this must be parenthesis, it will clear the sum to 1.
}
if (sum < 0)
{
return(false); //if it's smaller than zero, there is something wrong with the expression.
}
}
return(true);
}
/// <summary>
/// <para>
/// Only integers, parenthesis and elementary operators are allowed.
/// </para>
/// <para>
/// The prenthesis must be matched.
/// </para>
/// </summary>
/// <returns></returns>
protected bool checkChar()
{
foreach (char c in sourceexpression)
{
if (c < '0' || c > '9') //not a number
{
if (!OPERATORSlist.Contains(c)) //not a operator.
{
return(c == ')' || c == '(');
}
}
}
return(true);
}
/// <summary>
///
/// This method modify the current expression by adding space to left side and right side of the
/// operators or parenthesis making it easier to parse using split.
/// </summary>
protected void addSpace()
{
StringBuilder sb = new StringBuilder();
foreach (char c in sourceexpression)
{
if (!OPERATORSlist.Contains(c) && c != ')' && c != '(')//if it's not an operator or parenthesis
{
sb.Append(c);
}
else//It is a operator or prenthesis or something unexpected.
{
sb.Append(' ');
sb.Append(c);
sb.Append(' ');
}
}
this.diagestedexpression = sb.ToString();
}