public unsafe static CharacterDecompositionMapping Parse(string s)
{
if (string.IsNullOrEmpty(s))
{
return(default(CharacterDecompositionMapping));
}
CompatibilityFormattingTag tag = CompatibilityFormattingTag.Canonical;
int index;
if (s[0] == '<')
{
if (!EnumHelper <CompatibilityFormattingTag> .TryGetNamedValue(s.Substring(1, (index = s.IndexOf('>')) - 1), out tag))
{
throw new FormatException();
}
++index;
}
else
{
index = 0;
}
var buffer = stackalloc char[36]; // From the Unicode docs, a decomposition cannot have more than 18 code points.
int charIndex = 0;
while (index < s.Length && charIndex < 35)
{
char c = s[index];
if (c == ' ')
{
++index;
}
else
{
int codePoint = HexCodePoint.Parse(s, ref index);
if (codePoint < 0x10000)
{
buffer[charIndex++] = (char)codePoint;
}
else if (codePoint < 0x10FFFF)
{
codePoint -= 0x10000;
buffer[charIndex++] = (char)((codePoint >> 10) + 0xD800);
buffer[charIndex++] = (char)((codePoint & 0x3FF) + 0xDC00);
}
else
{
throw new FormatException("The code point was outside of the allowed range.");
}
}
}
return(new CharacterDecompositionMapping(tag, new string(buffer, 0, charIndex)));
}
public bool Read()
{
bool result;
if (result = reader.MoveToNextLine())
{
codePoint = HexCodePoint.ParsePrefixed(reader.ReadField());
propertyName = reader.ReadField();
propertyValue = reader.ReadField();
}
else
{
codePoint = 0;
propertyName = null;
propertyValue = null;
}
return(result);
}
private static async Task ProcessUnihanVariants(IDataSource unihanDataSource, UnicodeInfoBuilder builder)
{
using (var reader = new UnihanDataFileReader(await unihanDataSource.OpenDataFileAsync(UnihanVariantsFileName).ConfigureAwait(false)))
{
while (reader.Read())
{
// This statement is used to skip unhandled properties entirely.
switch (reader.PropertyName)
{
case UnihanProperty.kSimplifiedVariant:
case UnihanProperty.kTraditionalVariant:
break;
default:
// Ignore unhandled properties for now.
continue;
}
var entry = builder.GetUnihan(reader.CodePoint);
switch (reader.PropertyName)
{
case UnihanProperty.kSimplifiedVariant:
entry.SimplifiedVariant = char.ConvertFromUtf32(HexCodePoint.ParsePrefixed(reader.PropertyValue));
break;
case UnihanProperty.kTraditionalVariant:
entry.TraditionalVariant = char.ConvertFromUtf32(HexCodePoint.ParsePrefixed(reader.PropertyValue));
break;
default:
throw new InvalidOperationException();
}
}
}
}
