---

2.9 Searching

Procedure: rope-contains rope pattern [c=] ¶

Searches for the string pattern in rope and returns the first index that matches or #f. Characters are compared with c= (default: char=?). The Knutth-Pratt-Morris algorithm (see SRFI-13). The algorithm uses O(m) memory and O(p + m) time, where m is the length of the pattern and p is the length of the rope.

(define r (string->random-rope "I have never known any distress\
that an hour's reading did not relieve."))

;; Search for an exact match.
(rope-contains r "distress")
  ⇒ 23

;; Search case-independently.
(rope-contains r "HOUR'S" char-ci=?)
  ⇒ 40

;; A search that fails.
(rope-contains r "Montesquieu")
  ⇒ #f

Example 2.10: Searching text in a rope.