/// <summary>
/// Add Operand to this node
/// </summary>
/// <param name="operand"></param>
public void AddOperand(BoolExpr operand)
{
((OperandArray)Operands).Add(operand);
}
/// <summary>
/// Get pair of next token and boolexpr,
/// and then remove that characters and whitespaces
/// </summary>
private Tuple <Symbol, BoolExpr> Tokenize(StringBuilder src)
{
int nRead = 1;
Symbol symbol = Symbol.END;
BoolExpr expr = null;
// remove whitespaces
while (src.Length > 0 && @" \t\n\r\f".IndexOf(src[0]) != -1)
{
src.Remove(0, 1);
}
// end of source?
if (src.Length == 0)
{
return(Tuple.Create(symbol, expr));
}
switch (src[0])
{
case '(':
symbol = Symbol.LP;
break;
case ')':
symbol = Symbol.RP;
break;
case '1':
symbol = Symbol.VAL;
expr = new BoolExpr(BoolExpr.NodeType.TRUE);
break;
case '0':
symbol = Symbol.VAL;
expr = new BoolExpr(BoolExpr.NodeType.FALSE);
break;
case '!':
symbol = Symbol.NOT;
expr = new BoolExpr(BoolExpr.NodeType.NOT);
break;
case '&':
symbol = Symbol.AND;
expr = new BoolExpr(BoolExpr.NodeType.AND);
break;
case '|':
symbol = Symbol.OR;
expr = new BoolExpr(BoolExpr.NodeType.OR);
break;
case '=':
if (src.Length >= 2 && src[1] == '>')
{
nRead = 2;
symbol = Symbol.IMP;
expr = new BoolExpr(BoolExpr.NodeType.IMP);
}
break;
case '<':
if (src.Length >= 3 && src[1] == '=' && src[2] == '>')
{
nRead = 3;
symbol = Symbol.IFF;
expr = new BoolExpr(BoolExpr.NodeType.IFF);
}
break;
default: // identifier
var m = IdentifierSyntax.Match(src.ToString());
if (m.Success)
{
nRead = m.Value.Length;
symbol = Symbol.VAL;
expr = new BoolExpr(BoolExpr.NodeType.VAR, m.Value);
}
else
{
throw new Exception("Syntax Error -1");
}
break;
}
// remove tokenized characters
src.Remove(0, nRead);
return(Tuple.Create(symbol, expr));
}
