I see lots of functionality in the text2vec package to tokenize strings and make DTMs, but is there a way to create sequences? The Rstudio keras library has this, but it is incredibly slow. The idea being that instead of returning a matrix, you return a list of vectors of tokenized items, one per item in the input vector.
https://keras.rstudio.com/reference/texts_to_sequences.html
This feels like something that should be obvious but I can't seem to find it.