public Boolean ParseEntrypoints()
{
VerifySyntaxToken(TokenType.OpenBlock, "{");
while (true)
{
if (!Enumerator.HasToken())
{
throw new MicroassemblerParseException(Enumerator.Last, "Pair or } expected");
}
if (Enumerator.Current.TokenType == TokenType.CloseBlock)
{
Enumerator.Advance();
break;
}
if (Enumerator.Current.TokenType == TokenType.Pair)
{
Object[] pair = Enumerator.Current.Value as Object[];
Enumerator.Advance();
if (!(pair[1] is String))
{
throw new MicroassemblerParseException(Enumerator.Last, "Entrypoint pair value must be a symbol");
}
String symbol = (String)pair[1];
if (pair[0] is String)
{
String key = pair[0] as String;
switch (key.ToLower())
{
case "fetch":
Microprogram.FetchEntrypoint = symbol;
break;
case "interrupt":
Microprogram.InterruptEntrypoint = symbol;
break;
default: throw new MicroassemblerParseException(Enumerator.Last, $"Invalid entrypoint '{key}'");
}
}
else if (pair[0] is long)
{
int entryIndex = Convert.ToInt32(pair[0]);
if (Microprogram.InstructionEntrypoints.ContainsKey(entryIndex))
{
Console.WriteLine($"Warning: Duplicate entrypoint definition on line {Enumerator.Last.Line}, previous value overridden");
}
Microprogram.InstructionEntrypoints[entryIndex] = symbol;
}
else
{
throw new MicroassemblerParseException(Enumerator.Last, "Invalid Entrypoint");
}
if (Enumerator.HasNext() && Enumerator.Next.TokenType == TokenType.Pair)
{
VerifySyntaxToken(TokenType.ListDelimeter, ",");
}
if (Enumerator.HasNext() && Enumerator.Next.TokenType == TokenType.CloseBlock)
{
DiscardOptionalToken(TokenType.ListDelimeter, ",");
}
}
else
{
throw new MicroassemblerParseException(Enumerator.Current, "Pair expected");
}
}
return(true);
}