public ZMemory(byte[] data,
Action restart)
{
_restart = restart;
Header = new ZHeader(data.AsSpan(0, 31));
if (Header.Version > 5)
{
throw new NotSupportedException("ZMachine > V5 not currently supported");
}
// Version specific offsets
Offsets = VersionedOffsets.For(Header.Version);
Manager = new MemoryManager(data);
// ZMachine tables
Abbreviations = new ZAbbreviations(Header, Manager);
Dictionary = new ZDictionary(Header, Manager, Abbreviations);
ObjectTree = new ZObjectTree(Header, Manager, Abbreviations);
Globals = new ZGlobals(Header, Manager);
// Custom Stack with some abstractions for better testing.
Stack = new ZStack();
// Simple managers to abstract variable and argument usage
VariableManager = new VariableManager(Stack, Globals);
OperandManager = new OperandManager(Manager, Stack, VariableManager);
}
public ZObjectTree(ZHeader header,
IMemoryManager manager,
ZAbbreviations abbreviations)
{
_header = header;
var objectTableData = manager.AsSpan(header.ObjectTable);// memory.AsSpan(header.ObjectTable);
var(defaultProps, ptr) = GetDefaultProps(objectTableData);
DefaultProperties = defaultProps;
var lastObject = false;
ushort objNumber = 1;
_dict = new Dictionary <ushort, IZMachineObject>();
while (!lastObject && objNumber < 255)
{
// Objects end when the properties start!
ushort objectAddress = (ushort)(header.ObjectTable + ptr);
var min = _dict.Values.Any() ? _dict.Values.Min(v => v.PropertiesAddress) : ushort.MaxValue;
lastObject = objectAddress >= min;
if (!lastObject)
{
var zObj = new ZMachineObject(objNumber, objectAddress, header, manager, abbreviations, DefaultProperties);
_dict.Add(objNumber, zObj);
ptr += zObj.BytesRead;
objNumber++;
}
}
}
public ZsciiString(Span <byte> data, ZAbbreviations abbreviations, ZHeader header,
int zsciiWordsToUse = int.MaxValue)
{
_v2CharProvider = new V2CharProvider(abbreviations);
_header = header;
var chars = GetZsciiChars(data, zsciiWordsToUse);
BytesUsed = (ushort)(chars.Count / 3 * 2);
String = DecodeZsciiChars(chars, abbreviations);
}
public ZDictionary(ZHeader header, IMemoryManager manager, ZAbbreviations abbreviations)
{
var bytes = manager.AsSpan(header.Dictionary);
ushort addr = 0;
var numOfInputCodes = bytes[addr++];
InputCodes = bytes.AsSpan(addr, numOfInputCodes).ToArray();
addr += numOfInputCodes;
var zsciiStringArray = new ZsciiStringArray(bytes.AsSpan(addr), abbreviations, header);
Words = zsciiStringArray.Words;
EntryLength = zsciiStringArray.EntryLength;
WordStart = (ushort)(addr + zsciiStringArray.WordStart);
}
public ZsciiStringArray(Span <byte> data, ZAbbreviations abbreviations, ZHeader header)
{
var bytes = data.ToArray();
ushort ptr = 0;
EntryLength = bytes[ptr++];
var numEntries = bytes.GetUShort(ptr);
ptr += 2;
WordStart = ptr;
Words = new string[numEntries];
for (var i = 0; i < numEntries; i++)
{
var stringData = bytes.AsSpan(ptr);
var zStr = new ZsciiString(stringData, abbreviations, header, header.Version <= 3
? 2 : 3);
ptr += EntryLength;
Words[i] = zStr.String;
}
}
private string DecodeZsciiChars(List <byte> zChars, ZAbbreviations abbreviations)
{
_v2CharProvider.ResetTable();
var sb = new StringBuilder();
for (var i = 0; i < zChars.Count; i++)
{
if (zChars[i] == 0x00)
{
sb.Append(" ");
}
else if (_header.Version <= 2)
{
var zChar = zChars[i];
if (zChar == 1)
{
var abbrIdx = zChars[++i];
sb.Append(abbreviations.Abbreviations[abbrIdx]);
}
else
{
var(zCharTable, inc) = _v2CharProvider.GetCharTable(zChar);
i += inc;
if (i < zChars.Count)
{
zChar = zChars[i];
if (zChar == 6 && zCharTable[0] == ' ')
{
ushort x = (ushort)(zChars[i + 1] << 5 | zChars[i + 2]);
sb.Append(Convert.ToChar(x));
i += 2;
}
if (zChar > 5)
{
var realChar = zCharTable[zChar - 6];
sb.Append(realChar);
}
}
}
}
// else if (zChars[i] >= 0x01 && zChars[i] <= 0x03)
// {
// ushort offset = (ushort)(32 * (chars[i] - 1) + chars[++i]);
// ushort lookup = (ushort)(_abbreviationsTable + (offset * 2));
// ushort wordAddr = GetWord(lookup);
// List<byte> abbrev = GetZsciiChars((ushort)(wordAddr * 2));
// sb.Append(DecodeZsciiChars(abbrev));
// }
// else if (zChars[i] == 0x02 && _header.Version <= 2)
// {
// sb.Append(Convert.ToChar((zChars[++i] - 6) + 'A'));
// }
// else if (zChars[i] == 0x03 && _header.Version <= 2)
// {
// if (zChars.Count < i + 1)
// {
// sb.Append(Table[zChars[++i] - 6]);
// }
// }
// else if (zChars[i] == 0x04 && _header.Version <= 2)
// {
// sb.Append(Convert.ToChar((zChars[++i] - 6) + 'A'));
// }
// else if (zChars[i] == 0x05 && _header.Version <= 2)
// {
// if (zChars.Count < i + 1)
// {
// sb.Append(Table[zChars[++i] - 6]);
// }
// }
else if (abbreviations != null && IsAbbreviation(zChars[i]))
{
if (i + 1 <= zChars.Count - 1)
{
var offset = (ushort)(32 * (zChars[i] - 1) + zChars[++i]);
sb.Append(abbreviations.Abbreviations[offset]);
}
}
else if (zChars[i] == 0x04)
{
sb.Append(Convert.ToChar((zChars[++i] - 6) + 'A'));
}
else if (zChars[i] == 0x05)
{
if (i == zChars.Count - 1 || zChars[i + 1] == 0x05)
{
break;
}
if (zChars[i + 1] == 0x06)
{
var x = (ushort)(zChars[i + 2] << 5 | zChars[i + 3]);
i += 3;
sb.Append(Convert.ToChar(x));
}
else if (zChars[i + 1] == 0x07)
{
sb.AppendLine("");
i++;
}
else
{
sb.Append(Table[zChars[++i] - 6]);
}
}
else
{
sb.Append(Convert.ToChar((zChars[i] - 6) + 'a'));
}
}
return(sb.ToString());
}
public static string Get(Span <byte> data, ZAbbreviations abbreviations, ZHeader header) => new ZsciiString(data, abbreviations, header).String;
