repl-substring?
Name
repl-substring? -- Returns true if the specified substring can be replaced
Synopsis
(repl-substring? string target pos)
Description
Returns #t if target occurs at pos in string.
Author
Norman Walsh, <ndw@nwalsh.com>
Source Code
(define (repl-substring? string target pos)
  ;; Returns true if the specified substring can be replaced
  (let* ((could-match (<= (+ pos (string-length target)) 
			 (string-length string)))
	 (match (if could-match 
		    (substring string pos (+ pos (string-length target))) "")))
    (and could-match (string=? match target))))