/// next reads the next rune from the bufferred reader. Returns the rune(0) if
/// an error occurs (or io.EOF is returned).
private char Next()
{
var(ch, size, err) = _buf.ReadRune();
if (err)
{
// advance for error reporting
_srcPos.Column++;
_srcPos.Offset += size;
_lastCharLen = size;
return(EOF);
}
if (ch == GoBuffer.RuneError && size == 1)
{
_srcPos.Column++;
_srcPos.Offset += size;
_lastCharLen = size;
Err("illegal UTF-8 encoding");
return(ch);
}
// remember last position
_prevPos = _srcPos;
_srcPos.Column++;
_lastCharLen = size;
_srcPos.Offset += size;
if (ch == '\n')
{
_srcPos.Line++;
_lastLineLen = _srcPos.Column;
_srcPos.Column = 0;
}
// If we see a null character with data left, then that is an error
if (ch == '\x00' && _buf.Len() > 0)
{
Err("unexpected null character (0x00)");
return(EOF);
}
// debug
// fmt.Printf("ch: %q, offset:column: %d:%d\n", ch, s.srcPos.Offset, s.srcPos.Column)
return(ch);
}
/// diff compares a and b.
void Diff(string aname, string bname, slice <byte> a, slice <byte> b)
{
var buf = new GoBuffer(); // holding long error message
// compare lengths
if (a.Length != b.Length)
{
buf.WriteString($"\nlength changed: len({aname}) = {a.Length},"
+ " len({bname}) = {b.Length}");
}
// compare contents
var line = 1;
var offs = 1;
for (var i = 0; i < a.Length && i < b.Length; i++)
{
var ch = a[i];
if (ch != b[i])
{
buf.WriteString(string.Format("\n{0}:{1}:{2}: {3}", aname, line, i - offs + 1,
LineAt(a, offs)));
buf.WriteString(string.Format("\n{0}:{1}:{2}: {3}", bname, line, i - offs + 1,
LineAt(b, offs)));
buf.WriteString("\n\n");
break;
}
if (ch == '\n')
{
line++;
offs = i + 1;
}
}
if (buf.Len() > 0)
{
throw new IOException(buf.ToString());
}
}
// Update the cell width.
private void UpdateWidth()
{
cell.width += Utf8.RuneCount(buf.Bytes().Slice(pos, buf.Len()).ToArray());
pos = buf.Len();
}