racket/collects/readline/mzrl.ss
2006-09-28 03:50:38 +00:00

58 lines
2.0 KiB
Scheme

(module mzrl mzscheme
(require (lib "foreign.ss")) (unsafe!)
(provide readline readline-bytes
add-history add-history-bytes
set-completion-function!)
;; libtermcap maybe needed
(define libtermcap (with-handlers ([exn:fail? void]) (ffi-lib "libtermcap")))
(define libreadline (ffi-lib "libreadline"))
(define readline
(get-ffi-obj "readline" libreadline (_fun _string -> _string/eof)))
(define readline-bytes
(get-ffi-obj "readline" libreadline (_fun _bytes -> _bytes/eof)))
(define add-history
(get-ffi-obj "add_history" libreadline (_fun _string -> _void)))
(define add-history-bytes
(get-ffi-obj "add_history" libreadline (_fun _bytes -> _void)))
;; Simple completion: use this with a (string -> list-of string) function that
;; returns the completions for a given string. (should clean up bytes/string)
(define set-completion-function!
(case-lambda
[(func) (set-completion-function! _string)]
[(func type)
(if func
(set-ffi-obj! "rl_completion_entry_function" libreadline
(_fun type _int -> _pointer)
(completion-function func))
(set-ffi-obj! "rl_completion_entry_function" libreadline _pointer #f))]))
(define (completion-function func)
(let ([cur '()])
(define (complete str state)
(if (zero? state)
(begin (set! cur (func str)) (complete str 1))
(and (pair? cur)
(begin0 (malloc (add1 (bytes-length (car cur))) (car cur) 'raw)
(set! cur (cdr cur))))))
complete))
(set-ffi-obj! "rl_readline_name" libreadline _bytes #"mzscheme")
;; need to capture the real input port below
(define real-input-port (current-input-port))
(unless (eq? 'stdin (object-name (current-input-port)))
(fprintf (current-output-port)
"mzrl warning: could not capture the real input port"))
;; make it possible to run Scheme threads while waiting for input
(set-ffi-obj! "rl_event_hook" libreadline (_fun -> _int)
(lambda () (sync/enable-break real-input-port) 0))
)