- (textual-contains textual1 textual2 [start1 end1 start2 end2]) → idx-or-falseprocedure
- (textual-contains-right textual1 textual2 [start1 end1 start2 end2]) → idx-or-falseprocedure
Does the subtext of textual1 specified by start1 and end1 contain the sequence of characters given by the subtext of textual2 specified by start2 and end2?
Returns #f if there is no match. If start2 = end2, textual-contains returns start1 but textual-contains-right returns end1. Otherwise returns the index in textual1 for the first character of the first/last match; that index lies within the half-open interval [start1,end1), and the match lies entirely within the [start1,end1) range of textual1.
;; Searches "a geek" (textual-contains "eek -- what a geek." "ee" 12 18) ⇒ 15
Note: The names of these procedures do not end with a question mark. This indicates a useful value is returned when there is a match.