public ConvertTransform(IHostEnvironment env, Arguments args, IDataView input)
: base(env, RegistrationName, env.CheckRef(args, nameof(args)).Column,
input, null)
{
Host.AssertNonEmpty(Infos);
Host.Assert(Infos.Length == Utils.Size(args.Column));
_exes = new ColInfoEx[Infos.Length];
for (int i = 0; i < _exes.Length; i++)
{
DataKind kind;
KeyRange range;
var col = args.Column[i];
if (col.ResultType != null)
{
kind = col.ResultType.Value;
range = !string.IsNullOrEmpty(col.Range) ? KeyRange.Parse(col.Range) : col.KeyRange;
}
else if (col.KeyRange != null || !string.IsNullOrEmpty(col.Range))
{
kind = Infos[i].TypeSrc.IsKey ? Infos[i].TypeSrc.RawKind : DataKind.U4;
range = col.KeyRange ?? KeyRange.Parse(col.Range);
}
else if (args.ResultType != null)
{
kind = args.ResultType.Value;
range = !string.IsNullOrEmpty(args.Range) ? KeyRange.Parse(args.Range) : args.KeyRange;
}
else if (args.KeyRange != null || !string.IsNullOrEmpty(args.Range))
{
kind = Infos[i].TypeSrc.IsKey ? Infos[i].TypeSrc.RawKind : DataKind.U4;
range = args.KeyRange ?? KeyRange.Parse(args.Range);
}
else
{
kind = DataKind.Num;
range = null;
}
Host.CheckUserArg(Enum.IsDefined(typeof(DataKind), kind), nameof(args.ResultType));
PrimitiveType itemType;
if (!TryCreateEx(Host, Infos[i], kind, range, out itemType, out _exes[i]))
{
throw Host.ExceptUserArg(nameof(args.Column),
"source column '{0}' with item type '{1}' is not compatible with destination type '{2}'",
input.Schema.GetColumnName(Infos[i].Source), Infos[i].TypeSrc.ItemType, itemType);
}
}
SetMetadata();
}
/// <summary>
/// Attempt to parse the string into a data kind and (optionally) a key range. This method does not check whether
/// the returned <see cref="DataKind"/> can really be made into a key with the specified <paramref name="keyRange"/>.
/// </summary>
/// <param name="str">The string to parse.</param>
/// <param name="dataKind">The parsed data kind.</param>
/// <param name="keyRange">The parsed key range, or null if there's no key specification.</param>
/// <returns>Whether the parsing succeeded or not.</returns>
public static bool TryParseDataKind(string str, out DataKind dataKind, out KeyRange keyRange)
{
Contracts.CheckValue(str, nameof(str));
keyRange = null;
dataKind = default(DataKind);
int ich = str.IndexOf('[');
if (ich >= 0)
{
if (str[str.Length - 1] != ']')
{
return(false);
}
keyRange = KeyRange.Parse(str.Substring(ich + 1, str.Length - ich - 2));
if (keyRange == null)
{
return(false);
}
if (ich == 0)
{
return(true);
}
str = str.Substring(0, ich);
}
DataKind kind;
if (!Enum.TryParse <DataKind>(str, true, out kind))
{
return(false);
}
dataKind = kind;
return(true);
}
