Creating ngrams for characters in base R

char_ngram_base.R

ngram = function(x, y, n = 2) {
    if((which(x==y) + (n-2)) >= length(y)){return('')}
    return(
      paste0(unlist(
        lapply(0:(n-1), function(z){
          y[which(x == y) + z]
        })), collapse = ",")
        )
  }
  
#Usage
mapply(FUN = ngram,
       x = strsplit(character_input), 
       MoreArgs = list(y = strsplit(character_input), 
                       n = MaxNGrams)
       )