combine_vocabularies: Combines multiple vocabularies into one
In text2vec: Modern Text Mining Framework for R

Combines multiple vocabularies into one

combine_vocabularies(..., combine_stopwords = function(x)
  unique(unlist(lapply(x, attr, which = "stopwords"), use.names = FALSE)),
  combine_ngram = function(x) attr(x[[1]], "ngram"),
  combine_sep_ngram = function(x) attr(x[[1]], "sep_ngram"))

`...`	vocabulary objects created with create_vocabulary.
`combine_stopwords`	function to combine stopwords from input vocabularies. By default we take a union of all stopwords.
`combine_ngram`	function to combine lower and upper boundary for n-grams from input vocabularies. Usually these values should be the same, so we take this parameter from first vocabulary.
`combine_sep_ngram`	function to combine stopwords from input vocabularies. Usually these values should be the same, so we take this parameter from first vocabulary.