// Lexical scanner
private void Scan()
{
int k;
while (Cradle.Look == Cradle.CR)
{
Cradle.Fin();
}
if (Cradle.IsAlpha(Cradle.Look))
{
GetName();
}
else if (Cradle.IsDigit(Cradle.Look))
{
GetNum();
}
else if (IsOp(Cradle.Look))
{
GetOp();
}
else
{
Value = Cradle.Look.ToString();
Token = SymType.Operator;
Cradle.GetChar();
}
Cradle.SkipWhite();
}
// Parse and translate a math factor
private void Factor()
{
if (Cradle.Look == '(')
{
Cradle.Match('(');
Expression();
Cradle.Match(')');
}
else if (Cradle.IsAlpha(Cradle.Look))
Ident();
else
Cradle.EmitLn("MOVE #" + Cradle.GetNum() + ",D0");
}
// Get an identifier
private void GetName()
{
Value = "";
if (!Cradle.IsAlpha(Cradle.Look))
{
Cradle.Expected("Name");
}
while (Cradle.IsAlNum(Cradle.Look))
{
Value += char.ToUpper(Cradle.Look);
Cradle.GetChar();
}
Token = KWCode[Lookup(Value) + 1];
}
// Parse and translate a math factor
private int Factor()
{
if (Cradle.Look == '(')
{
Cradle.Match('(');
int value = Expression();
Cradle.Match(')');
return(value);
}
else if (Cradle.IsAlpha(Cradle.Look))
{
return(Table[Cradle.GetName() - 'A']);
}
else
{
return(Cradle.GetNum());
}
}
// Get an identifier
private void GetName()
{
int k;
Value = "";
if (!Cradle.IsAlpha(Cradle.Look))
{
Cradle.Expected("Name");
}
while (Cradle.IsAlNum(Cradle.Look))
{
Value += char.ToUpper(Cradle.Look);
Cradle.GetChar();
}
k = Lookup(Value);
if (k == -1)
{
Token = SymType.Ident;
}
else
{
Token = (SymType)k;
}
}