static void Main(string[] args)
{
// Abstract Syntax Tree (AST) for 5*10
Exp e = new BinaryExp(new NumericConstant(5),
new NumericConstant(10),
OPERATOR.MUL);
//
// Evaluate the Expression
//
//
Console.WriteLine(e.Evaluate(null));
// AST for -(10 + (30 + 50 ) )
e = new UnaryExp(
new BinaryExp(new NumericConstant(10),
new BinaryExp(new NumericConstant(30),
new NumericConstant(50),
OPERATOR.PLUS),
OPERATOR.PLUS),
OPERATOR.MINUS);
//
// Evaluate the Expression
//
Console.WriteLine(e.Evaluate(null));
//
// Pause for a key stroke
//
Console.Read();
}
public CodeExpression VisitUnary(UnaryExp u)
{
if (u.op == Op.Sub && u.e is RealLiteral real)
{
return(new RealLiteral("-" + real.Value, -real.NumericValue, real.Filename, real.Start, real.End).Accept(this));
}
var e = u.e.Accept(this);
return(new CodeUnaryOperatorExpression(mppyoptocsop[u.op], e));
}
public Constant VisitUnaryExp(UnaryExp unaryExp)
{
var c = unaryExp.exp.Accept(this);
if (!c.IsValid)
{
return(c);
}
if (unaryExp.op == TokenType.Minus)
{
return(Operator.Neg.ApplyConstant(c));
}
throw new NotImplementedException();
}
private Exp ParseFactor()
{
switch (t.Kind)
{
case Kind.Plus:
case Kind.Minus: {
var op = t;
Next();
var ret = new UnaryExp(op, ParseFactor()); // ParseExp?
return(ret);
}
case Kind.Number: {
var ret = new NumberExp(t);
Next();
return(ret);
}
case Kind.Open: {
var open = t;
Next();
var exp = ParseExpr();
if (t.Kind != Kind.Close)
{
throw new Exception("')' expected");
}
var close = t;
Next();
return(new ParenthesesExp(open, exp, close));
}
case Kind.Eof:
throw new Exception("number expected");
default:
throw new Exception($"number expected, found '{t.Raw}'");
}
}
public SerializedType VisitUnaryExp(UnaryExp unaryExp)
{
throw new NotImplementedException();
}
public void VisitUnary(UnaryExp u)
{
throw new NotImplementedException();
}
public DataType VisitUnary(UnaryExp u)
{
return(u.e.Accept(this));
}
public CodeExpression VisitUnary(UnaryExp u)
{
var e = u.e.Accept(this);
return(new CodeUnaryOperatorExpression(mppyoptocsop[u.op], e));
}
public void VisitUnary(UnaryExp u)
{
throw new NotImplementedException();
}
