public static Either <Error, Tuple <string, ExpressionBuilder> > ExprTerm(string s)
{
Either <Error, Tuple <string, ExpressionBuilder> > res1 = Unary(s);
if (res1.IsRight)
{
return(res1);
}
Either <Error, Tuple <string, Term> > res2 = Parser.Term(s);
if (res2.IsLeft)
{
return(res2.Left);
}
Tuple <string, Term> t2 = res2.Right;
ExpressionBuilder e = new ExpressionBuilder.Value(t2.Item2);
return(new Tuple <string, ExpressionBuilder>(t2.Item1, e));
}
public static Either <Error, Tuple <string, ExpressionBuilder> > Unary(string str)
{
str = Parser.Space(str);
if (str.StartsWith("!"))
{
str = Parser.Space(str.Substring(1));
Either <Error, Tuple <string, ExpressionBuilder> > resultExpression = Expr(str);
if (resultExpression.IsLeft)
{
return(resultExpression.Left);
}
Tuple <string, ExpressionBuilder> t = resultExpression.Right;
return(new Tuple <string, ExpressionBuilder>(t.Item1, new ExpressionBuilder.Unary(ExpressionBuilder.Op.Negate, t.Item2)));
}
if (str.StartsWith("("))
{
Either <Error, Tuple <string, ExpressionBuilder> > unaryParens = UnaryParens(str);
if (unaryParens.IsLeft)
{
return(unaryParens.Left);
}
Tuple <string, ExpressionBuilder> t = unaryParens.Right;
str = Parser.Space(str.Substring(1));
return(new Tuple <string, ExpressionBuilder>(t.Item1, t.Item2));
}
ExpressionBuilder e;
Either <Error, Tuple <string, Term> > res = Parser.Term(str);
if (res.IsRight)
{
Tuple <string, Term> t = res.Right;
str = Parser.Space(t.Item1);
e = new ExpressionBuilder.Value(t.Item2);
}
else
{
Either <Error, Tuple <string, ExpressionBuilder> > res2 = UnaryParens(str);
if (res2.IsLeft)
{
return(res2.Left);
}
Tuple <string, ExpressionBuilder> t = res2.Right;
str = Parser.Space(t.Item1);
e = t.Item2;
}
if (str.StartsWith(".Length"))
{
str = Parser.Space(str.Substring(9));
return(new Tuple <string, ExpressionBuilder>(str, new ExpressionBuilder.Unary(ExpressionBuilder.Op.Length, e)));
}
else
{
return(new Error(str, "unexpected token"));
}
}