Expression AndExpression()
{
Expression ret = EqualityExpression();
while (Current.TokenKind == TokenKind.OpAnd)
{
Consume(); // Or
Expression rhs = EqualityExpression();
ret = new BinaryExpression(ret.Line, ret.Col, ret, TokenKind.OpAnd, rhs);
}
return ret;
}
private Expression EqualityExpression()
{
Expression ret = RelationalExpression();
while (Current.TokenKind == TokenKind.OpIs
|| Current.TokenKind == TokenKind.OpIsNot)
{
Token tok = Consume(); // consume operator
Expression rhs = RelationalExpression();
ret = new BinaryExpression(ret.Line, ret.Col, ret, tok.TokenKind, rhs);
}
return ret;
}
Expression OrExpression()
{
Expression ret = AndExpression();
while (Current.TokenKind == TokenKind.OpOr)
{
Consume(); // Or
Expression rhs = AndExpression();
ret = new BinaryExpression(ret.Line, ret.Col, ret, TokenKind.OpOr, rhs);
}
return ret;
}
private Expression RelationalExpression()
{
Expression ret = PrimaryExpression();
while (Current.TokenKind == TokenKind.OpLt
|| Current.TokenKind == TokenKind.OpLte
|| Current.TokenKind == TokenKind.OpGt
|| Current.TokenKind == TokenKind.OpGte)
{
Token tok = Consume(); // consume operator
Expression rhs = PrimaryExpression();
ret = new BinaryExpression(ret.Line, ret.Col, ret, tok.TokenKind, rhs);
}
return ret;
}
protected object EvalBinaryExpression(BinaryExpression exp)
{
switch (exp.Operator)
{
case JumboTCMS.TEngine.Parser.TokenKind.OpOr:
{
object lhsValue = EvalExpression(exp.Lhs);
if (Util.ToBool(lhsValue))
return true;
object rhsValue = EvalExpression(exp.Rhs);
return Util.ToBool(rhsValue);
}
case JumboTCMS.TEngine.Parser.TokenKind.OpAnd:
{
object lhsValue = EvalExpression(exp.Lhs);
if (!Util.ToBool(lhsValue))
return false;
object rhsValue = EvalExpression(exp.Rhs);
return Util.ToBool(rhsValue);
}
case JumboTCMS.TEngine.Parser.TokenKind.OpIs:
{
object lhsValue = EvalExpression(exp.Lhs);
object rhsValue = EvalExpression(exp.Rhs);
return lhsValue.Equals(rhsValue);
}
case JumboTCMS.TEngine.Parser.TokenKind.OpIsNot:
{
object lhsValue = EvalExpression(exp.Lhs);
object rhsValue = EvalExpression(exp.Rhs);
return !lhsValue.Equals(rhsValue);
}
case JumboTCMS.TEngine.Parser.TokenKind.OpGt:
{
object lhsValue = EvalExpression(exp.Lhs);
object rhsValue = EvalExpression(exp.Rhs);
IComparable c1 = lhsValue as IComparable;
IComparable c2 = rhsValue as IComparable;
if (c1 == null || c2 == null)
return false;
else
return c1.CompareTo(c2) == 1;
}
case JumboTCMS.TEngine.Parser.TokenKind.OpLt:
{
object lhsValue = EvalExpression(exp.Lhs);
object rhsValue = EvalExpression(exp.Rhs);
IComparable c1 = lhsValue as IComparable;
IComparable c2 = rhsValue as IComparable;
if (c1 == null || c2 == null)
return false;
else
return c1.CompareTo(c2) == -1;
}
case JumboTCMS.TEngine.Parser.TokenKind.OpGte:
{
object lhsValue = EvalExpression(exp.Lhs);
object rhsValue = EvalExpression(exp.Rhs);
IComparable c1 = lhsValue as IComparable;
IComparable c2 = rhsValue as IComparable;
if (c1 == null || c2 == null)
return false;
else
return c1.CompareTo(c2) >= 0;
}
case JumboTCMS.TEngine.Parser.TokenKind.OpLte:
{
object lhsValue = EvalExpression(exp.Lhs);
object rhsValue = EvalExpression(exp.Rhs);
IComparable c1 = lhsValue as IComparable;
IComparable c2 = rhsValue as IComparable;
if (c1 == null || c2 == null)
return false;
else
return c1.CompareTo(c2) <= 0;
}
default:
throw new TemplateRuntimeException("Operator " + exp.Operator.ToString() + " is not supported.", exp.Line, exp.Col);
}
}
