82 lines
3.8 KiB
Scheme
82 lines
3.8 KiB
Scheme
|
(define-syntax interact-clause-test
|
||
|
|
(syntax-rules (filter eof)
|
||
|
|
((interact-clause-test char break) #t)
|
||
|
|
((interact-clause-test eof break (eof body ...) clause2 ...)
|
||
|
|
(begin body ...))
|
||
|
|
((interact-clause-test eof break clause1 clause2 ...)
|
||
|
|
(interact-clause-test eof break clause2 ...))
|
||
|
|
((interact-clause-test char break (eof body ...) clause2 ...)
|
||
|
|
(interact-clause-test char break clause2 ...))
|
||
|
|
((interact-clause-test char break (filter filter-proc) clause2 ...)
|
||
|
|
(and (filter-proc char break)
|
||
|
|
(interact-clause-test char break clause2 ...)))
|
||
|
|
((interact-clause-test char break (test-char k body ...) clause2 ...)
|
||
|
|
(if (eq? char test-char)
|
||
|
|
(and (let ((k break)) body ...)
|
||
|
|
(interact-clause-test char break clause2 ...))
|
||
|
|
(interact-clause-test char break clause2 ...)))))
|
||
|
|
|
||
|
|
;;; Allow user to interact with program (sometimes there's just no other way)
|
||
|
|
;;; (interact task) simply switches the user into interact mode with the task.
|
||
|
|
;;;
|
||
|
|
;;; (interact task clause ...) filters the input. The clause can either be a
|
||
|
|
;;; character clause (character continuation-variable exp ...) or a filter
|
||
|
|
;;; clause (filter proc). A character clause matches the character given,
|
||
|
|
;;; links the continuation variable to the continuation out of the
|
||
|
|
;;; interaction, and runs the expressions. A filter clause runs the given
|
||
|
|
;;; filter-function with two arguments: the character entered and the
|
||
|
|
;;; continuation out of the interaction. In both cases, if the filter returns
|
||
|
|
;;; true, the expression falls through. If the expression falls through to
|
||
|
|
;;; the bottom, the character is printed. Note that the interaction will
|
||
|
|
;;; continue anyway, unless the continuation was explicitly called.
|
||
|
|
|
||
|
|
(define-syntax interact
|
||
|
|
(syntax-rules ()
|
||
|
|
|
||
|
|
;; If there is just one argument, simply enable transfer.
|
||
|
|
((interact with)
|
||
|
|
(call-with-current-continuation
|
||
|
|
(lambda (break)
|
||
|
|
(let ((ivec (make-vector 2))
|
||
|
|
(ivec0 (current-input-port))
|
||
|
|
(ivec1 (task:in with)))
|
||
|
|
(with-errno-handler ((e p) ((errno/io) #f))
|
||
|
|
(let lp ()
|
||
|
|
(vector-set! ivec 0 ivec0)
|
||
|
|
(vector-set! ivec 1 ivec1)
|
||
|
|
(select! ivec '#() '#())
|
||
|
|
(if (char-ready? ivec0)
|
||
|
|
(write-string (read-string/partial 256 ivec0)
|
||
|
|
(task:out with)))
|
||
|
|
(if (char-ready? ivec1)
|
||
|
|
(write-string (read-string/partial 256 ivec1)))
|
||
|
|
(lp)))))))
|
||
|
|
|
||
|
|
;; If there is more than one argument,
|
||
|
|
;;enable transfer and allow escape keys.
|
||
|
|
((interact with clauses ...)
|
||
|
|
(call-with-current-continuation
|
||
|
|
(lambda (break)
|
||
|
|
(let ((ivec (make-vector 2))
|
||
|
|
(ivec0 (current-input-port))
|
||
|
|
(ivec1 (task:in with)))
|
||
|
|
(with-errno-handler ((e p)
|
||
|
|
((errno/io)
|
||
|
|
(interact-clause-test eof #f clauses ...)))
|
||
|
|
(let lp ()
|
||
|
|
(vector-set! ivec 0 ivec0)
|
||
|
|
(vector-set! ivec 1 ivec1)
|
||
|
|
(select! ivec '#() '#())
|
||
|
|
(if (char-ready? (current-input-port))
|
||
|
|
(for-each (lambda (transfer)
|
||
|
|
;; Test for indicated escape keys.
|
||
|
|
(and (interact-clause-test transfer break
|
||
|
|
clauses ...)
|
||
|
|
;; Only write if all clauses "fell through"
|
||
|
|
(write-char transfer (task:out with))))
|
||
|
|
(string->list (read-string/partial 256 (current-inpu
|
||
|
|
t-port)))))
|
||
|
|
(if (char-ready? (task:in with))
|
||
|
|
(write-string (read-string/partial 256 (task:in with))))
|
||
|
|
(lp)))))))))
|