Removed ability to save filters from legacy filter code

[harishsk]

Fixes #5335

The offending code in ResultProcessor wasn't being used at all. So I have deleted that.

And as per @yaeldekel the StatefulFilterTransform is a legacy filter from TLC and is not part of the ML.NET public API. It is being used internally in some time series code. But it doesn't need the ability to be saved.

We should at some point, upgrade the time series code to use the new CustomMappingTransform and delete the StatefulFilterTransform.

Until then I have deleted the SerializableLambdaTransform and the associated functionality in LambdaTransformBase.

[yaeldekel]

ICanSaveModel [](start = 50, length = 13)

Since this doesn't need to implement ICanSaveModel, and there is no other functionality in this base class, I would delete it. You mentioned that it is being used internally only as an IDataView, in that case I would make the deriving classes (I only found one, StatefulFilterTransform) implement IDataView instead of ITransformTemplate. #Resolved

[harishsk]

Thanks @yaeldekel. I have deleted LambdaTransformBase. I replaced ITransformTemplate with IDataTransform instead of IDataView because SequentialTransformBase in the time series code was relying on it being IDataTransform

---

In reply to: 466166529 [](ancestors = 466166529)

[harishsk]

Never mind. Your advice was correct. The earlier fix resulted in test failures. I have now changed StatefulFilterTransform to implement IDataView

---

In reply to: 466589874 [](ancestors = 466589874,466166529)

[antoniovs1029]

LGTM

[antoniovs1029]

Just to mention that this also is meant to fix CA2301 on #5334 😄

[codecov]

Codecov Report

Merging #5338 into master will decrease coverage by 4.07%.
The diff coverage is 73.33%.

@@            Coverage Diff             @@
##           master    #5338      +/-   ##
==========================================
- Coverage   73.92%   69.84%   -4.08%     
==========================================
  Files        1020      775     -245     
  Lines      190126   145190   -44936     
  Branches    20437    18529    -1908     
==========================================
- Hits       140549   101414   -39135     
+ Misses      44048    38611    -5437     
+ Partials     5529     5165     -364     

Flag	Coverage Δ
#Debug	69.84% <73.33%> (-4.08%)	⬇️
#production	69.84% <73.33%> (+0.16%)	⬆️
#test	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...rc/Microsoft.ML.ResultProcessor/ResultProcessor.cs	46.85% <0.00%> (+2.19%)	⬆️
...Microsoft.ML.TimeSeries/SequentialTransformBase.cs	77.01% <ø> (ø)
...crosoft.ML.TimeSeries/SequentialTransformerBase.cs	55.35% <ø> (ø)
...Microsoft.ML.Transforms/StatefulFilterTransform.cs	83.03% <75.00%> (-9.07%)	⬇️
src/Microsoft.ML.Transforms/LambdaTransform.cs	94.33% <100.00%> (+27.37%)	⬆️
src/Microsoft.ML.Maml/MAML.cs	23.78% <0.00%> (-0.98%)	⬇️
...StandardTrainers/Standard/LinearModelParameters.cs	66.32% <0.00%> (-0.26%)	⬇️
...soft.ML.Predictor.Tests/CmdLine/CmdIndenterTest.cs
test/Microsoft.ML.Benchmarks/Harness/Metrics.cs
... and 253 more