public static object ReadNumberHandler(LispReader stream, string ch, int arg)
{
var token = stream.ReadToken();
switch (ch)
{
case "r":
{
return(Number.ParseNumberBase(token, arg));
}
case "o":
{
return(Number.ParseNumberBase(token, 8));
}
case "b":
{
return(Number.ParseNumberBase(token, 2));
}
case "x":
{
return(Number.ParseNumberBase(token, 16));
}
default:
{
// not reached
return(null);
}
}
}
public string ParseSingleLineString()
{
// supports backslash escapes
// single line
StringBuilder buf = new StringBuilder();
while (true)
{
var ch = ReadChar();
if (IsEof || ch == '\n')
{
throw MakeScannerException("Unterminated string");
}
if (ch == '"')
{
break;
}
if (ch == '\\')
{
ch = ReadChar();
switch (ch)
{
case 'x':
{
var ch1 = ReadChar();
var ch2 = ReadChar();
if (IsEof)
{
throw MakeScannerException("Unterminated string");
}
var n = (int)Number.ParseNumberBase(new string(new char[] { ch1, ch2 }), 16);
buf.Append(Convert.ToChar(n));
break;
}
case 'u':
{
var ch1 = ReadChar();
var ch2 = ReadChar();
var ch3 = ReadChar();
var ch4 = ReadChar();
if (IsEof)
{
throw MakeScannerException("Unterminated string");
}
var n = (int)Number.ParseNumberBase(new string(new char[] { ch1, ch2, ch3, ch4 }), 16);
buf.Append(Convert.ToChar(n));
break;
}
default:
{
if (IsEof)
{
throw MakeScannerException("Unterminated string");
}
buf.Append(Runtime.UnescapeCharacter(ch));
break;
}
}
}
else
{
buf.Append(ch);
}
}
return(buf.ToString());
}