public static RuleExpression Parse(string rule)
{
Stack <Symbol> stack = new Stack <Symbol>();
int i = 0;
while (i < rule.Length)
{
char c = rule[i++];
Symbol symbol;
if (char.IsDigit(c))
{
int num = i - 1;
while (i < rule.Length && char.IsDigit(rule[i]))
{
i++;
}
symbol = new Symbol();
symbol.Type = RuleExpression.ESymbolType.CompareExpression;
symbol.Value = Convert.ToInt64(rule.Substring(num, i - num), CultureInfo.InvariantCulture);
}
else
{
if (char.IsLetter(c))
{
string text = c.ToString(CultureInfo.InvariantCulture);
while (i < rule.Length && char.IsLetter(rule[i]))
{
text += rule[i++].ToString();
}
if (text != null)
{
if (text == "AND")
{
symbol = new Symbol(RuleExpression.ESymbolType.TerminalAnd);
goto IL_177;
}
if (text == "OR")
{
symbol = new Symbol(RuleExpression.ESymbolType.TerminalOr);
goto IL_177;
}
if (text == "NOT")
{
symbol = new Symbol(RuleExpression.ESymbolType.TerminalNot);
goto IL_177;
}
}
throw new Exception(string.Concat(new object[]
{
"Unknown terminal symbol '",
text,
"' at position ",
i
}));
}
if (c == '(')
{
symbol = new Symbol(RuleExpression.ESymbolType.TerminalLPar);
}
else if (c == ')')
{
symbol = new Symbol(RuleExpression.ESymbolType.TerminalRPar);
}
else if (c == '=')
{
symbol = new Symbol();
symbol.Type = RuleExpression.ESymbolType.Operator;
symbol.Value = CompareExpression.ECompareOperator.EQUAL;
}
else
{
if (!char.IsWhiteSpace(c))
{
throw new Exception("Unknown character at position " + i);
}
symbol = null;
}
}
IL_177:
if (symbol != null)
{
stack.Push(symbol);
bool flag = true;
while (flag)
{
Symbol symbol2 = stack.Pop();
Symbol symbol3;
if (stack.Count > 0)
{
symbol3 = stack.Pop();
}
else
{
symbol3 = new Symbol(RuleExpression.ESymbolType.Unknown);
}
Symbol symbol4;
if (stack.Count > 0)
{
symbol4 = stack.Pop();
}
else
{
symbol4 = new Symbol(RuleExpression.ESymbolType.Unknown);
}
bool flag2 = false;
if (symbol4.Type == RuleExpression.ESymbolType.CompareExpression && symbol3.Type == RuleExpression.ESymbolType.Operator && symbol2.Type == RuleExpression.ESymbolType.CompareExpression)
{
stack.Push(new Symbol(RuleExpression.ESymbolType.Value)
{
Value = new ValueExpression((long)symbol2.Value)
});
flag2 = true;
}
else if (EmpiricalRuleParser.IsExpression(symbol4) && symbol3.Type == RuleExpression.ESymbolType.TerminalAnd && EmpiricalRuleParser.IsExpression(symbol2))
{
stack.Push(new Symbol(RuleExpression.ESymbolType.AndExpression)
{
Value = new AndExpression((RuleExpression)symbol4.Value, (RuleExpression)symbol2.Value)
});
flag2 = true;
}
else if (EmpiricalRuleParser.IsExpression(symbol4) && symbol3.Type == RuleExpression.ESymbolType.TerminalOr && EmpiricalRuleParser.IsExpression(symbol2))
{
stack.Push(new Symbol(RuleExpression.ESymbolType.OrExpression)
{
Value = new OrExpression((RuleExpression)symbol4.Value, (RuleExpression)symbol2.Value)
});
flag2 = true;
}
else if (symbol3.Type == RuleExpression.ESymbolType.TerminalNot && EmpiricalRuleParser.IsExpression(symbol2))
{
Symbol symbol5 = new Symbol(RuleExpression.ESymbolType.NotExpression);
symbol5.Value = new NotExpression((RuleExpression)symbol2.Value);
if (symbol4.Type != RuleExpression.ESymbolType.Unknown)
{
stack.Push(symbol4);
}
stack.Push(symbol5);
flag2 = true;
}
else if (symbol4.Type == RuleExpression.ESymbolType.TerminalLPar && EmpiricalRuleParser.IsExpression(symbol3) && symbol2.Type == RuleExpression.ESymbolType.TerminalRPar)
{
stack.Push(symbol3);
flag2 = true;
}
if (!flag2)
{
if (symbol4.Type != RuleExpression.ESymbolType.Unknown)
{
stack.Push(symbol4);
}
if (symbol3.Type != RuleExpression.ESymbolType.Unknown)
{
stack.Push(symbol3);
}
stack.Push(symbol2);
flag = false;
}
else
{
flag = true;
}
}
}
}
if (stack.Count == 0)
{
return(null);
}
if (stack.Count != 1)
{
throw new Exception("Could not completely reduce tokens");
}
Symbol symbol6 = stack.Pop();
if (!EmpiricalRuleParser.IsExpression(symbol6))
{
throw new Exception("Illegal last token");
}
return((RuleExpression)symbol6.Value);
}
public static RuleExpression ParseEmpiricalRule(string rule)
{
return(EmpiricalRuleParser.Parse(rule));
}