private void GridRAM_CellEndEdit(object sender, DataGridViewCellEventArgs e)
{
edtMessages.Clear();
errors = new SortedDictionary <byte, string>();
labels = new Dictionary <string, byte>();
for (byte addr = 0; addr < 100; addr++)
{
string line = (string)GridRAM[1, addr].Value;
if (line == null)
{
continue;
}
line = line.Trim().ToUpper();
//Make sure the labels are accounted for
if (line[0] == ':')
{
string[] parts = line.Split(new char[] { ' ' }, 2, StringSplitOptions.RemoveEmptyEntries);
//validation: what can a label be called?
parts[0] = parts[0].Substring(1); //remove the :
int dummy; //not ever used
if (parts[0] == "" || new string[] { "ADD", "SUB", "LDA", "STO", "BR", "BRP", "BRZ", "HLT", "IN", "OUT", "DAT" }.Contains(parts[0]) || int.TryParse(parts[0], out dummy))
{
AddError(addr, "Label '" + parts[0] + "' is invalid!");
continue;
}
//update the label dictionary
if (labels.ContainsKey(parts[0]))
{
labels[parts[0]] = addr;
}
else
{
labels.Add(parts[0], addr);
}
}
}
for (byte addr = 0; addr < 100; addr++)
{
string line = (string)GridRAM[1, addr].Value;
if (line == null)
{
continue;
}
line = line.Trim().ToUpper();
if (line[0] == ':')
{
string[] parts = line.Split(new char[] { ' ' }, 2, StringSplitOptions.RemoveEmptyEntries);
try
{
line = parts[1];//remove the label
}
catch (IndexOutOfRangeException) { continue; }
}
//now translate this into opcode
try
{
string[] parts = line.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
//translate labels
for (int i = 0; i < parts.Length; i++)
{
if (labels.ContainsKey(parts[i]))
{
parts[i] = labels[parts[i]].ToString();
}
}
line = "";
foreach (string part in parts)
{
line += part + " ";
}
ushort opcode = Mnemonic.ToByteCode(line);
LMC.RAM[addr] = opcode;
}
catch (Exception except)
{
AddError(addr, except.Message);
}
}
}
static public ushort ToByteCode(string instruction)
{
instruction = instruction.ToUpper();
string[] parts = instruction.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
if (parts.Length == 0)
{
throw new Exception("An empty string is not valid syntax");
}
//check for numbers
ushort potentialNumber;
if (ushort.TryParse(parts[0], out potentialNumber))
{
return(potentialNumber);
}
else if (parts[0] == "DAT")
{
return(Mnemonic.ToByteCode(parts[1]));//DAT is followed either by an instruction or a number
}
else if (parts[0] == "IN")
{
if (parts.Length > 1)
{
throw new Exception("Unexpected arguments for IN instruction");
}
else
{
return(901);
}
}
else if (parts[0] == "OUT")
{
if (parts.Length > 1)
{
throw new Exception("Unexpected arguments for OUT instruction");
}
else
{
return(902);
}
}
else if (parts[0] == "HLT")
{
if (parts.Length > 1)
{
throw new Exception("Unexpected arguments for HLT instruction");
}
else
{
return(0);
}
}
else
{
if (parts.Length < 2)
{
throw new Exception("Argument expected for " + parts[0] + " instruction");
}
if (parts.Length > 2)
{
throw new Exception("Unexpected second argument for " + parts[0] + " instruction");
}
ushort address;
try { address = ushort.Parse(parts[1]); }
catch (Exception) { throw new Exception("Argument is invalid"); }
if (address > 99)
{
throw new Exception("Argument is out of bounds!");
}
//otherwise we should be ready to parse an instruction with a parameter
switch (parts[0])
{
case "ADD": return((ushort)(100 + address));
case "SUB": return((ushort)(200 + address));
case "STO": return((ushort)(300 + address));
case "LDA": return((ushort)(500 + address));
case "BR": return((ushort)(600 + address));
case "BRZ": return((ushort)(700 + address));
case "BRP": return((ushort)(800 + address));
default: throw new Exception("Invalid opcode " + parts[0]);
}
}
}