public static Utf8Iterator GetFirst(this Utf8String src)
{
var it = src.GetIterator();
it.MoveNext();
return(it);
}
public static void Escape(Utf8String s, IStore w)
{
if (s.IsEmpty)
{
return;
}
var it = s.GetIterator();
while (it.MoveNext())
{
var l = it.CurrentByteLength;
if (l == 1)
{
var b = it.Current;
switch (b)
{
case (Byte)'"':
case (Byte)'\\':
case (Byte)'/':
// \\ prefix
w.Write((Byte)'\\');
w.Write(b);
break;
case (Byte)'\b':
w.Write((Byte)'\\');
w.Write((Byte)'b');
break;
case (Byte)'\f':
w.Write((Byte)'\\');
w.Write((Byte)'f');
break;
case (Byte)'\n':
w.Write((Byte)'\\');
w.Write((Byte)'n');
break;
case (Byte)'\r':
w.Write((Byte)'\\');
w.Write((Byte)'r');
break;
case (Byte)'\t':
w.Write((Byte)'\\');
w.Write((Byte)'t');
break;
default:
w.Write(b);
break;
}
// ascii
}
else if (l == 2)
{
w.Write(it.Current);
w.Write(it.Second);
}
else if (l == 3)
{
w.Write(it.Current);
w.Write(it.Second);
w.Write(it.Third);
}
else if (l == 4)
{
w.Write(it.Current);
w.Write(it.Second);
w.Write(it.Third);
w.Write(it.Fourth);
}
else
{
throw new ParserException("invalid utf8");
}
}
}
public static int Unescape(Utf8String s, IStore w)
{
int writeCount = 0;
Action <Byte> Write = c =>
{
if (w != null)
{
w.Write(c);
}
++writeCount;
};
var it = s.GetIterator();
while (it.MoveNext())
{
var l = it.CurrentByteLength;
if (l == 1)
{
if (it.Current == (Byte)'\\')
{
var c = it.Second;
switch (c)
{
case (Byte)'\\':
case (Byte)'/':
case (Byte)'"':
// remove prefix
Write(c);
it.MoveNext();
continue;
case (Byte)'b':
Write((Byte)'\b');
it.MoveNext();
continue;
case (Byte)'f':
Write((Byte)'\f');
it.MoveNext();
continue;
case (Byte)'n':
Write((Byte)'\n');
it.MoveNext();
continue;
case (Byte)'r':
Write((Byte)'\r');
it.MoveNext();
continue;
case (Byte)'t':
Write((Byte)'\t');
it.MoveNext();
continue;
}
}
Write(it.Current);
}
else if (l == 2)
{
Write(it.Current);
Write(it.Second);
}
else if (l == 3)
{
Write(it.Current);
Write(it.Second);
Write(it.Third);
}
else if (l == 4)
{
Write(it.Current);
Write(it.Second);
Write(it.Third);
Write(it.Fourth);
}
else
{
throw new ParserException("invalid utf8");
}
}
return(writeCount);
}