/// <summary>
/// Defines a binary-to-text encoding.
/// Additional decode characters let you add aliases, and a filter callback can be used
/// to make decoding case-insensitive among other things.
/// </summary>
/// <param name="characterSet">The characters of the encoding.</param>
/// <param name="msbComesFirst">
/// <c>true</c> to begin with the most-significant bit of each byte.
/// Otherwise, the encoding begins with the least-significant bit.
/// </param>
/// <param name="additionalDecodeCharacters">
/// A dictionary of alias characters, or <c>null</c> if no aliases are desired.
/// </param>
/// <param name="decodeFilterCallback">
/// A callback to map arbitrary characters onto the characters that can be decoded.
/// </param>
public BaseEncoding(string characterSet, bool msbComesFirst,
IDictionary <char, int> additionalDecodeCharacters,
BaseEncodingDecodeFilterCallback decodeFilterCallback)
{
Check.Null("characterSet", characterSet);
if (!BitMath.IsPositivePowerOf2(characterSet.Length))
{
throw Exceptions.Argument("characterSet",
"Length must be a power of 2.");
}
if (characterSet.Length > 256)
{
throw Exceptions.Argument("characterSet",
"Character sets with over 256 characters are not supported.");
}
_bitCount = 31 - BitMath.CountLeadingZeros(characterSet.Length);
_bitMask = (1 << _bitCount) - 1;
_characters = characterSet;
_msbComesFirst = msbComesFirst;
_decodeFilterCallback = decodeFilterCallback;
_values = additionalDecodeCharacters != null
? new Dictionary <char, int>(additionalDecodeCharacters)
: new Dictionary <char, int>();
for (int i = 0; i < characterSet.Length; i++)
{
char ch = characterSet[i];
if (_values.ContainsKey(ch))
{
throw Exceptions.Argument("Duplicate characters are not supported.",
"characterSet");
}
_values.Add(ch, (byte)i);
}
}
/// <summary>
/// Defines a binary-to-text encoding.
/// Additional decode characters let you add aliases, and a filter callback can be used
/// to make decoding case-insensitive among other things.
/// </summary>
/// <param name="characterSet">The characters of the encoding.</param>
/// <param name="msbComesFirst">
/// <c>true</c> to begin with the most-significant bit of each byte.
/// Otherwise, the encoding begins with the least-significant bit.
/// </param>
/// <param name="additionalDecodeCharacters">
/// A dictionary of alias characters, or <c>null</c> if no aliases are desired.
/// </param>
/// <param name="decodeFilterCallback">
/// A callback to map arbitrary characters onto the characters that can be decoded.
/// </param>
public BaseEncoding(string characterSet, bool msbComesFirst,
IDictionary<char, int> additionalDecodeCharacters,
BaseEncodingDecodeFilterCallback decodeFilterCallback)
{
Check.Null("characterSet", characterSet);
if (!BitMath.IsPositivePowerOf2(characterSet.Length))
{
throw Exceptions.Argument("characterSet",
"Length must be a power of 2.");
}
if (characterSet.Length > 256)
{
throw Exceptions.Argument("characterSet",
"Character sets with over 256 characters are not supported.");
}
_bitCount = 31 - BitMath.CountLeadingZeros(characterSet.Length);
_bitMask = (1 << _bitCount) - 1;
_characters = characterSet;
_msbComesFirst = msbComesFirst;
_decodeFilterCallback = decodeFilterCallback;
_values = additionalDecodeCharacters != null
? new Dictionary<char, int>(additionalDecodeCharacters)
: new Dictionary<char, int>();
for (int i = 0; i < characterSet.Length; i ++)
{
char ch = characterSet[i];
if (_values.ContainsKey(ch))
{
throw Exceptions.Argument("Duplicate characters are not supported.",
"characterSet");
}
_values.Add(ch, (byte)i);
}
}
