//constructor used for testing purpose only
public ExpressionBuilder(
IParenthesize parenthesizer,
string expression,
int type
) : this(parenthesizer) {
if (type < 0 || type > 5)
{
throw new ArgumentException("Invalid Key Type.");
}
var typeTable = new Dictionary <int, KeyType>()
{
{ 0, KeyType.Value },
{ 1, KeyType.Unary },
{ 2, KeyType.Binary },
{ 3, KeyType.Left },
{ 4, KeyType.Right },
{ 5, KeyType.Empty },
};
if (expression != null)
{
Buffer.Add(expression);
}
KeyHistory.Add(typeTable[type]);
}
public void AddValue(decimal input)
{
if (!CanAddValue())
{
throw new InvalidOperationException("Operands Must be Separated by Operators.");
}
Buffer.Add(input.ToString());
KeyHistory.Add(KeyType.Value);
}
private void AddLeftParenthesis(string input)
{
//left parenthesis cannot immediately follow a value or unary operator
if (KeyHistory.Last() == KeyType.Value || KeyHistory.Last() == KeyType.Unary)
{
throw new InvalidOperationException("Missing Operators.");
}
//left parenthesis cannot immediately follow right parenthesis
if (KeyHistory.Last() == KeyType.Right)
{
throw new InvalidOperationException("Mismatched Parentheses.");
}
Buffer.Add(input);
KeyHistory.Add(KeyType.Left);
}
public void AddBinary(string input)
{
//consecutive binary operator input is not allowed
if (KeyHistory.Last() == KeyType.Binary)
{
throw new InvalidOperationException("Missing Operand.");
}
/*
* when binary operator input follows left parenthesis or nothing,
* a value of zero will be added as default operand
*/
if (KeyHistory.Last() == KeyType.Left || KeyHistory.Last() == KeyType.Empty)
{
AddValue(0);
}
Buffer.Add(input);
KeyHistory.Add(KeyType.Binary);
}
private void AddRightParenthesis(string input)
{
//right parenthesis cannot immediately follow binary operator
if (KeyHistory.Last() == KeyType.Binary)
{
throw new InvalidOperationException("Missing Operand.");
}
//parentheses must match
if (MissingParentheses(Expression) < 1)
{
throw new InvalidOperationException("Mismatched Parentheses.");
}
if (KeyHistory.Last() == KeyType.Left)
{
AddValue(0);
}
Buffer.Add(input);
KeyHistory.Add(KeyType.Right);
}