FeaturizeText was upgraded to allow specification of n-grams for words and characters. However, now it awkward to use FeaturizeText without specifying n-grams. It is now necessary to explicitly set CharFeatureExtractor as null.

This is how to compose a bag-of-words with the current API:

var pipeline = mlContext.Transforms.Text.FeaturizeText( "Features", new TextFeaturizingEstimator.Options { KeepPunctuations = false, OutputTokens = true, CharFeatureExtractor = null, WordFeatureExtractor = new WordBagEstimator.Options { NgramLength = 1}, VectorNormalizer = TextFeaturizingEstimator.NormFunction.None }, "SentimentText");

I would expect to be able to do something like

CharFeatureExtractor = new WordBagEstimator.Options { NgramLength = 0},

But this throws an error that Skipgrams is not less-than NgramLength, and Skipgrams must be positive.

Overall, it is a bit awkward and not obvious that you have to manually null a option. Is this the API we want to ship in v1.0?