You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
sugar/string.rkt

14 lines
566 B
Racket

#lang racket/base
11 years ago
(require "define/contract.rkt" "coerce.rkt")
11 years ago
(define+provide/contract (starts-with? str starter)
11 years ago
(coerce/string? coerce/string? . -> . coerce/boolean?)
(and (<= (string-length starter) (string-length str))
(equal? (substring str 0 (string-length starter)) starter)))
11 years ago
(define+provide/contract (ends-with? str ender)
11 years ago
(coerce/string? coerce/string? . -> . coerce/boolean?)
(and (<= (string-length ender) (string-length str))
(equal? (substring str (- (string-length str) (string-length ender)) (string-length str)) ender)))