public charconst(int line, int pos, string str, BekCharModes mode = BekCharModes.BV16)
{
this.line = line;
this.pos = pos;
IFormatProvider prov = new System.Globalization.NumberFormatInfo();
string s;
if (str.StartsWith("'"))
{
var str1 = str.Substring(1, str.Length - 2);
if (str1.Length == 1)
val = (int)str1[0];
else
{
var unesc = System.Text.RegularExpressions.Regex.Unescape(str1);
if (unesc.Length != 1)
throw new BekParseException(string.Format("Illeagal character constant {0}", str));
val = (int)unesc[0];
}
}
else if (str.StartsWith("0x")) //must be hexadecimal number
{
s = str.Substring(2, str.Length - 2);
if (!int.TryParse(s, NumberStyles.AllowHexSpecifier, prov, out val))
throw new BekException(string.Format("Invalid hexadecimal numeral {0}", str));
}
else
{
s = str;
if (!int.TryParse(s, out val)) //first try to parse as decimal numeral
{
//we know at this point that the character constant string starts and ends with a single quote
string buffer = s.Substring(1, s.Length - 2);
if (mode != BekCharModes.BV32)
{
string intermediate = "";
try
{
intermediate = System.Text.RegularExpressions.Regex.Unescape(buffer);
}
catch (Exception e)
{
throw new BekException(string.Format("Illeagal character constant {0}", s), e);
}
if (intermediate.Length > 1)
{
throw new BekException(string.Format("Illeagal character constant {0}", s));
}
this.val = (int)intermediate[0];
}
else
{
try
{
string intermediate = System.Text.RegularExpressions.Regex.Unescape(buffer);
// extract unicode code points as integers
var e = StringInfo.GetTextElementEnumerator(intermediate);
if (e.MoveNext())
{
this.val = char.ConvertToUtf32(e.GetTextElement(), 0);
}
else
{
throw new Exception();
}
if (e.MoveNext())
{
throw new Exception();
}
}
catch (Exception e)
{
throw new BekException(string.Format("Illeagal character constant {0}", s), e);
}
}
}
}
}
public charconst(string str, BekCharModes mode = BekCharModes.BV16)
: this(0, 0, str)
{
}