Hello.
I wrote a tiny and silly joking program as below.
;;;;;;;;;;;;;;;;;;
#lang racket
(require srfi/48)
;;;;; Data
(define *script*
#hasheq((intro . "Let me help to show you the age of marrage to be happy,
Lady!~%~%1. You need only one input later.~%2. If you'd like to step
forward, just hit the Enter/Return key.~%~%Do you want to play? [y/n]")
(first-step . "~%At first, please call a two-digit number
whichever you like in your mind.~%Then please hit the Enter/Return key~%~%")
(second-step . "Please add the one's digit and the ten's digit in
your mind.~%Then please hit the Enter/Return key.~%~%")
(question . "Is the number still a two-digit number? [y/n] ")
(third-step . "~%Next, please multiply the answer you've just got
by 9 in your mind.~%Then please hit the Enter/Return key.~%~%")
(forth-step . "Now, Please add the one's digit and the ten's
digit of the answer you've just got in your mind.~%Then please hit the
Enter/Return key.~%~%")
(fifth-step . "At last, please add the number of guys you've
slept with to the answer you've just got in your mind.~%Then please input
the answer you've got below.~%==> ")
(conclusion . "~%You'd better get married when you are ~a years
old to have a happy life,~%and that implies you've slept with ~a ~a
~a.~%~%")
(only . "only")
(nothing . "")
(man . "man")
(men . "men")
(play-again? . "Play again?")))
;;;;; Environment
(define *env* (hasheq 'phase #f 'messages *script*))
;;;;; Read
(define (y-or-n?)
(let ((i (read)))
(let ((sym (string->symbol (string-upcase (substring (symbol->string i)
0 1)))))
(case sym
((Y) #t)
((N) #f)
(else (raise 'not-yes-nor-no))))))
(define (parser x env)
(case (hash-ref env 'phase)
((intro question play-again?) (values (y-or-n?) env))
((fifth-step) (let ((i (read)))
(values (if (integer? i)
i
(raise 'input-error)) env)))
((first-step
second-step
third-step
forth-step) (read-char) (values x env)) ;;; THIS PART DOESN'T WORK
PROPERLY!
(else (values x env))))
;;;;; Eval
(define (interp x env)
(case (hash-ref env 'phase)
((intro play-again?) (if x
(values x (hash-set env 'phase 'first-step))
(exit)))
((first-step) (values x (hash-set env 'phase 'second-step)))
((second-step) (values x (hash-set env 'phase 'question)))
((question) (values x (hash-set env 'phase (if x
'second-step
'third-step))))
((third-step) (values x (hash-set env 'phase 'forth-step)))
((forth-step) (values x (hash-set env 'phase 'fifth-step)))
((fifth-step) (values (- x 9) (hash-set env 'phase 'conclusion)))
((conclusion) (values x (hash-set env 'phase 'play-again?)))
(else (values x (hash-set env 'phase 'intro)))))
;;;;; Print
(define (print x env)
(let ((c (hash-ref env 'phase))
(s (hash-ref env 'messages)))
(case c
((intro
first-step
second-step
question
third-step
forth-step
fifth-step
play-again?) (format #t (hash-ref s c)))
((conclusion) (format #t
(hash-ref s c)
(+ x 9)
(hash-ref s (if (< x 2)
'only
'nothing))
x
(hash-ref s (if (< x 2)
'man
'men))))))
(flush-output)
(values x env))
;;;;; REPL
(define (main x env)
(let-values (((x env) (parser x env)))
(let-values (((x env) (interp x env)))
(let-values (((x env) (print x env)))
(main x env)))))
(main #f *env*)
;;;;;;;;;;;;;;;;;;;;;; THE END OF PROGRAM
I would like to implement something like "HIT ENTER TO CONTINUE", and I
used read-char for it; however it doesn't work as I wished.
It seems like when I hit the enter key, it keeps having something other
than #\newline in the stream, and two messages of data are shown at once.
This is not what I mean.
I tried using charterm, but as implied, it does not work on Windows and
says ttf; therefore I gave up using the library on Windows.
Is there any good idea to implement "HIT ENTER TO CONTINUE"?
By the way, I'm using Windows 7 and Racket V.5.93.
Thanx.
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