Serialisable Term()
{
if (lxr.tok == Sym.MINUS || lxr.tok == Sym.PLUS || lxr.tok == Sym.NOT)
{
var op = SExpression.Op.Plus;
switch (lxr.tok)
{
case Sym.MINUS:
op = SExpression.Op.UMinus; break;
case Sym.NOT:
op = SExpression.Op.Not; break;
case Sym.PLUS:
Next();
return(Term());
}
Next();
return(new SExpression(Term(), op, Serialisable.Null));
}
var a = Factor();
while (lxr.tok == Sym.TIMES || lxr.tok == Sym.DIVIDE)
{
SExpression.Op op = SExpression.Op.And;
switch (lxr.tok)
{
case Sym.TIMES: op = SExpression.Op.Times; break;
case Sym.DIVIDE: op = SExpression.Op.Divide; break;
}
Next();
a = new SExpression(a, op, Factor());
}
if (lxr.tok == Sym.IS)
{
Next();
Mustbe(Sym.NULL);
return(new SExpression(a, SExpression.Op.Eql, Serialisable.Null));
}
if (lxr.tok == Sym.IN)
{
Next();
return(new SInPredicate(a, Value()));
}
return(a);
}
Serialisable OneVal()
{
Serialisable a = Term();
while (lxr.tok == Sym.PLUS || lxr.tok == Sym.MINUS)
{
SExpression.Op op = SExpression.Op.Or;
switch (lxr.tok)
{
case Sym.PLUS: op = SExpression.Op.Plus; break;
case Sym.MINUS: op = SExpression.Op.Minus; break;
}
Next();
a = new SExpression(a, op, Term());
}
return(a);
}
