/// <summary>
/// Gets the specified BASIC code line
/// </summary>
/// <param name="progStart">Code line address in the memory</param>
/// <param name="lineVm">BASIC line view model</param>
/// <returns></returns>
public ushort GetBasicLine(ushort progStart, out BasicLineViewModel lineVm)
{
lineVm = new BasicLineViewModel
{
LineNo = Memory[progStart++] * 0x100 + Memory[progStart++],
Length = Memory[progStart++] + Memory[progStart++] * 0x100
};
var lineEnd = progStart + lineVm.Length;
if (lineEnd > Memory.Length - 1)
{
lineEnd = Memory.Length - 1;
}
var spaceBeforeToken = false;
var sb = new StringBuilder(256);
while (progStart < lineEnd)
{
var nextSymbol = Memory[progStart++];
if (nextSymbol >= 0xA5)
{
// --- This is a token
if (spaceBeforeToken)
{
sb.Append(" ");
}
var tokenCode = nextSymbol - 0xA5;
var token = _tokens[tokenCode];
sb.Append(token);
if (tokenCode > 2 && char.IsLetter(token[token.Length - 1]))
{
sb.Append(" ");
spaceBeforeToken = false;
}
continue;
}
// --- Whatever we print, the next token needs a space
spaceBeforeToken = true;
if (nextSymbol >= 0x20 && nextSymbol <= 0x7F)
{
// --- Printable character
sb.Append((char)nextSymbol);
continue;
}
if (nextSymbol == 0x0D)
{
continue;
}
if (nextSymbol == 0x0E)
{
// --- Skip the binary form of a floating point number
progStart += 5;
continue;
}
// --- Non-printable character, let's display it with an escape sequence
sb.Append($"°{nextSymbol:X2}°");
}
lineVm.Text = sb.ToString();
return(progStart);
}
/// <summary>
/// Gets the specified BASIC code line
/// </summary>
/// <param name="progStart">Code line address in the memory</param>
/// <param name="lineVm">BASIC line view model</param>
/// <returns></returns>
public ushort GetBasicLine(ushort progStart, out BasicLineViewModel lineVm)
{
lineVm = new BasicLineViewModel
{
LineNo = Memory[progStart++] * 0x100 + Memory[progStart++],
Length = Memory[progStart++] + Memory[progStart++] * 0x100
};
var lineEnd = progStart + lineVm.Length;
if (lineEnd > Memory.Length - 1)
{
lineEnd = Memory.Length - 1;
}
var spaceBeforeToken = false;
var withinQuotes = false;
var sb = new StringBuilder(256);
while (progStart < lineEnd)
{
var nextSymbol = Memory[progStart++];
if (nextSymbol >= 0xA5)
{
// --- This is a token
if (spaceBeforeToken)
{
sb.Append(" ");
}
var tokenCode = nextSymbol - 0xA5;
var token = _tokens[tokenCode];
sb.Append(token);
if (tokenCode > 2 && char.IsLetter(token[token.Length - 1]))
{
sb.Append(" ");
spaceBeforeToken = false;
}
continue;
}
// --- Whatever we print, the next token needs a space
spaceBeforeToken = true;
// --- Skip ENTER
if (nextSymbol == 0x0D)
{
continue;
}
// --- Skip binary number characters
if (nextSymbol == 0x0E)
{
// --- Skip the binary form of a floating point number
progStart += 5;
continue;
}
if (nextSymbol == 0x22)
{
// --- Printable character
sb.Append((char)nextSymbol);
withinQuotes = !withinQuotes;
continue;
}
if (MimicZxBasic && !withinQuotes && nextSymbol < 0x20)
{
// --- Skip all remaining control characters in ZX BASIC mode
continue;
}
if (nextSymbol >= 0x20 && nextSymbol <= 0x7F)
{
// --- Printable character
if (withinQuotes)
{
if (nextSymbol == (int)'\\')
{
sb.Append(MimicZxBasic ? "\\\\" : "\\");
continue;
}
else if (nextSymbol == 0x60)
{
sb.Append(MimicZxBasic ? "\\`" : "Ł");
continue;
}
else if (nextSymbol == 0x7f)
{
sb.Append(MimicZxBasic ? "\\*" : "©");
continue;
}
}
else
{
if (nextSymbol == (int)'\\')
{
sb.Append("\\");
continue;
}
else if (nextSymbol == 0x60)
{
sb.Append("Ł");
continue;
}
else if (nextSymbol == 0x7f)
{
sb.Append("©");
continue;
}
}
sb.Append((char)nextSymbol);
continue;
}
// --- Non-printable character, let's display it with an escape sequence
if (MimicZxBasic && withinQuotes)
{
if (nextSymbol >= 0x90 && nextSymbol <= 0xA4)
{
// --- Handle UDG chars in ZX BASIC
sb.Append($"\\{(char)(nextSymbol - 0x90 + 'A')}");
continue;
}
var lookahead = progStart < Memory.Length ? Memory[progStart] : -1;
switch (nextSymbol)
{
case 0x10:
if (lookahead >= 0)
{
sb.Append("\\{i" + lookahead + "}");
progStart++;
}
break;
case 0x11:
if (lookahead >= 0)
{
sb.Append("\\{p" + lookahead + "}");
progStart++;
}
break;
case 0x12:
if (lookahead >= 0)
{
sb.Append("\\{f" + lookahead + "}");
progStart++;
}
break;
case 0x13:
if (lookahead >= 0)
{
sb.Append("\\{b" + lookahead + "}");
progStart++;
}
break;
case 0x80:
sb.Append("\\ ");
break;
case 0x81:
sb.Append("\\ '");
break;
case 0x82:
sb.Append("\\' ");
break;
case 0x83:
sb.Append("\\''");
break;
case 0x84:
sb.Append("\\ .");
break;
case 0x85:
sb.Append("\\ :");
break;
case 0x86:
sb.Append("\\'.");
break;
case 0x87:
sb.Append("\\':");
break;
case 0x88:
sb.Append("\\. ");
break;
case 0x89:
sb.Append("\\.'");
break;
case 0x8a:
sb.Append("\\: ");
break;
case 0x8b:
sb.Append("\\:'");
break;
case 0x8c:
sb.Append("\\..");
break;
case 0x8d:
sb.Append("\\.:");
break;
case 0x8e:
sb.Append("\\:.");
break;
case 0x8f:
sb.Append("\\::");
break;
default:
sb.Append($"#{nextSymbol & 0xff}");
break;
}
}
else
{
sb.Append($"°{nextSymbol:X2}°");
}
}
lineVm.Text = sb.ToString();
return(progStart);
}