74 lines
2.2 KiB
Scheme
74 lines
2.2 KiB
Scheme
(let ()
|
|
(define with-error-handler
|
|
(lambda (p thunk)
|
|
(let ([old-error-handler (current-error-handler)])
|
|
(dynamic-wind
|
|
(lambda ()
|
|
(current-error-handler
|
|
(lambda args
|
|
(current-error-handler old-error-handler)
|
|
(apply p args)
|
|
(apply error args))))
|
|
thunk
|
|
(lambda ()
|
|
(current-error-handler old-error-handler))))))
|
|
|
|
(define eval-depth 0)
|
|
|
|
(define display-prompt
|
|
(lambda (i)
|
|
(if (fx= i eval-depth)
|
|
(display " " (console-output-port))
|
|
(begin
|
|
(display ">" (console-output-port))
|
|
(display-prompt (fx+ i 1))))))
|
|
|
|
(define wait
|
|
(lambda (eval escape-k)
|
|
(call/cc
|
|
(lambda (k)
|
|
(with-error-handler
|
|
(lambda args
|
|
(reset-input-port! (console-input-port))
|
|
;(display "repl catch\n" (console-output-port))
|
|
(apply print-error args)
|
|
(k (void)))
|
|
(lambda ()
|
|
(display-prompt 0)
|
|
(let ([x (read (console-input-port))])
|
|
(cond
|
|
[(eof-object? x)
|
|
(newline (console-output-port))
|
|
(escape-k (void))]
|
|
[else
|
|
(call-with-values
|
|
(lambda () (eval x))
|
|
(lambda v*
|
|
(unless (andmap (lambda (v) (eq? v (void))) v*)
|
|
(for-each
|
|
(lambda (v)
|
|
(write v (console-output-port))
|
|
(newline (console-output-port)))
|
|
v*))))]))))))
|
|
(wait eval escape-k)))
|
|
|
|
(define new-cafe
|
|
(lambda (eval)
|
|
(dynamic-wind
|
|
(lambda () (set! eval-depth (fxadd1 eval-depth)))
|
|
(lambda ()
|
|
(call/cc
|
|
(lambda (k)
|
|
(wait eval k))))
|
|
(lambda () (set! eval-depth (fxsub1 eval-depth))))))
|
|
|
|
(primitive-set! 'new-cafe
|
|
(case-lambda
|
|
[() (new-cafe eval)]
|
|
[(p)
|
|
(unless (procedure? p)
|
|
(error 'new-cafe "~s is not a procedure" p))
|
|
(new-cafe p)]))
|
|
)
|
|
|