public List<ParsedCommand> Parse()
{
List<ParsedCommand> parsedCommands = new List<ParsedCommand>();
CleanCommands();
foreach (var command in _commands)
{
ParsedCommand pc = new ParsedCommand();
pc.CommandType = GetCommandType(command);
switch (pc.CommandType)
{
case CommandType.A_COMMAND:
case CommandType.L_COMMAND:
pc.Symbol = GetSymbol(command);
break;
case CommandType.C_COMMAND:
pc.Dest = GetDestination(command);
pc.Comp = GetComputation(command);
pc.Jump = GetJump(command);
break;
}
parsedCommands.Add(pc);
}
return parsedCommands;
}
private string GetAddressInstruction(ParsedCommand pc)
{
int symbol = int.Parse(pc.Symbol);
string leadingZeroes = "";
string binarySymbol = Convert.ToString(symbol, 2);
for (int i = 0; i < (16 - binarySymbol.Length); i++)
{
leadingZeroes += "0";
}
return leadingZeroes + binarySymbol;
}
private string GetComputation(ParsedCommand pc)
{
string compBits = "";
if (pc.Comp.IndexOf('A') >= 0) compBits += "0";
else if (pc.Comp.IndexOf('M') >= 0) compBits += "1";
else if (pc.Comp == "D") compBits += "0";
else compBits += "0";
switch (pc.Comp)
{
case "0":
compBits += "101010";
break;
case "1":
compBits += "111111";
break;
case "-1":
compBits += "111010";
break;
case "D":
compBits += "001100";
break;
case "A":
case "M":
compBits += "110000";
break;
case "!D":
compBits += "001101";
break;
case "!A":
case "!M":
compBits += "110001";
break;
case "-D":
compBits += "001111";
break;
case "-A":
case "-M":
compBits += "110011";
break;
case "D+1":
compBits += "011111";
break;
case "A+1":
case "M+1":
compBits += "110111";
break;
case "D-1":
compBits += "001110";
break;
case "A-1":
case "M-1":
compBits += "110010";
break;
case "D+A":
case "D+M":
compBits += "000010";
break;
case "D-A":
case "D-M":
compBits += "010011";
break;
case "A-D":
case "M-D":
compBits += "000111";
break;
case "D&A":
case "D&M":
compBits += "000000";
break;
case "D|A":
case "D|M":
compBits += "010101";
break;
}
return compBits;
}
private string GetJump(ParsedCommand pc)
{
string jumpBits = "";
switch (pc.Jump)
{
case "JGT":
jumpBits = "001";
break;
case "JEQ":
jumpBits = "010";
break;
case "JGE":
jumpBits = "011";
break;
case "JLT":
jumpBits = "100";
break;
case "JNE":
jumpBits = "101";
break;
case "JLE":
jumpBits = "110";
break;
case "JMP":
jumpBits = "111";
break;
default:
jumpBits = "000";
break;
}
return jumpBits;
}
private string GetDestination(ParsedCommand pc)
{
string destBits = "";
if (!string.IsNullOrEmpty(pc.Dest))
{
if (pc.Dest.Contains("A")) destBits += "1";
else destBits += "0";
if (pc.Dest.Contains("D")) destBits += "1";
else destBits += "0";
if (pc.Dest.Contains("M")) destBits += "1";
else destBits += "0";
}
else
{
destBits = "000";
}
return destBits;
}