(require-extension npdiff format-textdiff)

(define t1 (open-input-file "tests/large0"))
(define text1 (read-lines t1))
(define t2 (open-input-file "tests/large1"))
(define text2 (read-lines t2))
(define hunks (textdiff text1 text2 3))
(define format make-format-textdiff)

(print (textdiff->sexp hunks))
((format 'ed) (current-output-port) hunks)
((format 'normal) (current-output-port) hunks)
((format 'rcs) (current-output-port) hunks)
((format 'context) (current-output-port) hunks 
 "large0" "Sun Jun  3 18:28:06 2007" 
 "large1" "Sun Jun  3 18:28:06 2007")