private static void findLabels(Parser parser, SymbolTable symbols)
{
int ROM = 0;
string symbol;
while (parser.hasMoreCommands())
{
try {
parser.advance();
} catch (EndOfStreamException) {
break;
}
switch (parser.commandType())
{
case Parser.L_COMMAND:
symbol = parser.symbol();
if (symbols.contains(symbol))
{
throw new InvalidOperationException("Cannot redefine label: " + symbol);
}
symbols.addEntry(symbol, ROM);
break;
case Parser.A_COMMAND:
case Parser.C_COMMAND:
ROM++;
break;
}
}
parser.reset();
}
private static void assemble(Parser parser, SymbolTable symbols, StreamWriter output)
{
Code translator = new Code();
int RAM = 16;
while (parser.hasMoreCommands())
{
int value = 0;
try {
parser.advance();
} catch (EndOfStreamException) {
break;
}
switch (parser.commandType())
{
case Parser.A_COMMAND:
int address;
string symbol = parser.symbol();
bool isNumber = int.TryParse(symbol, out address);
if (!isNumber)
{
if (!symbols.contains(symbol))
{
symbols.addEntry(symbol, RAM++);
}
address = symbols.getAddress(symbol);
}
value = address;
break;
case Parser.C_COMMAND:
value |= 7 << 13; // 1110000000000000 == 57344
value |= translator.comp(parser.comp());
value |= translator.dest(parser.dest());
value |= translator.jump(parser.jump());
break;
case Parser.L_COMMAND:
continue;
}
string instruction = Convert.ToString(value, 2).PadLeft(16, '0');
output.WriteLine(instruction);
}
parser.reset();
}
