Move public facing classes used in Samples into appropriate namespaces.

[codemzs]

As part of the grand rename of namespaces, let's finalize the set of namespaces of public-facing components.

Class/Interface/Enum/Delegate	Current Namespace	New Namespace	Current Path
TransformerScope	Microsoft.ML.Data	Microsoft.ML	E:\machinelearning\src\Microsoft.ML.Data\DataLoadSave\TransformerChain.cs
ITransformerChainAccessor	Microsoft.ML.Data	Microsoft.ML	E:\machinelearning\src\Microsoft.ML.Data\DataLoadSave\TransformerChain.cs
TransformerChain	Microsoft.ML.Data	Microsoft.ML	E:\machinelearning\src\Microsoft.ML.Data\DataLoadSave\TransformerChain.cs
IDataView	Microsoft.ML.Data	Microsoft.ML	E:\machinelearning\src\Microsoft.ML.Core\Data\IDataView.cs
ISchema	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\IDataView.cs
delegate void ValueGetter(ref TValue value);	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\IDataView.cs
abstract class Row	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\IDataView.cs
CursorState	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\IDataView.cs
abstract class RowCursor	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\IDataView.cs
interface IRowReadableAs	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Data\DataView\TypedCursor.cs
class RowCursor	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Data\DataView\TypedCursor.cs
interface ICursorable	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Data\DataView\TypedCursor.cs
class TypedCursorable	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Data\DataView\TypedCursor.cs
static class CursoringUtils	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Data\DataView\TypedCursor.cs
MultiFileSource	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Data\DataLoadSave\MultiFileSource.cs
VBuffer	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\VBuffer.cs
BinaryPredictionTransformer	Microsoft.ML.Data	Make a catalog entry in ML namespace? Or move to ML namespace	E:\machinelearning\src\Microsoft.ML.Data\Scorers\PredictionTransformer.cs
PredictionTransformerBase<TModel, TScorer>	Microsoft.ML.Data	Make a catalog entry in ML namespace? Or move to ML namespace	E:\machinelearning\src\Microsoft.ML.Data\Scorers\PredictionTransformer.cs
SingleFeaturePredictionTransformerBase<TModel, TScorer>	Microsoft.ML.Data	Make a catalog entry in ML namespace? Or move to ML namespace	E:\machinelearning\src\Microsoft.ML.Data\Scorers\PredictionTransformer.cs
AnomalyPredictionTransformer	Microsoft.ML.Data	Make a catalog entry in ML namespace? Or move to ML namespace	E:\machinelearning\src\Microsoft.ML.Data\Scorers\PredictionTransformer.cs
MulticlassPredictionTransformer	Microsoft.ML.Data	Make a catalog entry in ML namespace? Or move to ML namespace	E:\machinelearning\src\Microsoft.ML.Data\Scorers\PredictionTransformer.cs
RegressionPredictionTransformer	Microsoft.ML.Data	Make a catalog entry in ML namespace? Or move to ML namespace	E:\machinelearning\src\Microsoft.ML.Data\Scorers\PredictionTransformer.cs
RankingPredictionTransformer	Microsoft.ML.Data	Make a catalog entry in ML namespace? Or move to ML namespace	E:\machinelearning\src\Microsoft.ML.Data\Scorers\PredictionTransformer.cs
interface Itransformer	Microsoft.ML.Core.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\IEstimator.cs
interface IEstimator	Microsoft.ML.Core.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\IEstimator.cs
interface IDataReaderEstimator<in TSource, out TReader>	Microsoft.ML.Core.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\IEstimator.cs
interface IDataReader	Microsoft.ML.Core.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\IEstimator.cs
class SchemaShape	Microsoft.ML.Core.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\IEstimator.cs
RoleMappedData	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\RoleMappedSchema.cs
RoleMappedSchema	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Core\Data\RoleMappedSchema.cs
ColumnCursorExtensions	Microsoft.ML.Data	?	E:\machinelearning\src\Microsoft.ML.Data\Utilities\ColumnCursor.cs

CC: @TomFinley

[TomFinley]

It seems like the core concepts of the API (IEstimator/ITransformer/IDataReader) should live in Microsoft.ML. I'd argue VBuffer as a core data type should also live there, since vector valued columns are very important. MultiFileSource should live in same namespace as whatever IDataReader winds up living in. That probably means Microsoft.ML.

IRowReadableAs and TypedCursorable are internal. So is ICursorable almost certainly could be internal. CursorUtils, like any utils, should be internal. Same with Role mapped data, and role mapped schema. Indeed it might be helpful when composing lists to check what things are already internal.

ColumnCursorExtensions is a fairly poor API that should be reviewed, but in principle if properly designed I'd probably, as an auxiliary method, put it in Microsoft.ML.Data.

Regarding specific transformers, I have no idea what "Make a catalog entry in ML namespace?" means. But I'm not sure whether this should be Microsoft.ML, Microsoft.ML.Data, or Microsoft.ML.Transformers, or something else altogether.

Note: to keep this helpful, might be nice if you could group the list, since obviously it is not scalable for you to list every individual class, and have someone have to tell you what to do with it. Instead maybe try to propose a general policy, some sort of set of rules that are consistent.

[codemzs]

@sfilipi Do we care about this anymore?

[sfilipi]

I believe this has been addressed from the other angles, of checking the namespaces directly to see what types they expose.

I'd just skim over the user facing samples, like the cookbook, Microsoft.ML.Samples and the Microsoft.ML.FunctionalTests before closing it.