val length : t -> intmodule Buf : sig ... endtype ur_text = textThe type of original texts.
type ur_index = indexThe type of indexes of original texts.
refer t i j returns the part of t from i until j. The character pointed by j is not included in the result. If j is equal to i or located before j, the result is an empty string.
context t returns the tuple (s, i, j) such that t = refer s i j.