<:> N-grams
An n-gram is a continuous string of elements taken from a
sequence
This may be a sentence, a melody or a linguistic corpus.
For example, from the sentence `give me a break' we can extract various
n-grams.
- 1-grams (`unigrams'): `give', `a'
- 2-grams (`bigrams'): `me a', `a break'
- 3-grams (`trigrams'): `give me a', 'me a break'