On Thu, Jan 6, 2011 at 1:06 AM, Matthias Felleisen <[email protected]>wrote:
> > Start reading HtDP/2e @ http://www.ccs.neu.edu/home/matthias/HtDP2e/ > > It uses strings, which may be more familiar to you and which accommodate a > bit more variety. > > Then switch back to HtDP/1e. > > > On Jan 5, 2011, at 7:18 AM, Sayth Renshaw wrote: > > > > > Can someone expand on the syntax for symbols? I can develop the > check-guess game simply without symbols but cannot with symbols. > > Trying many versions of the symbol syntax but with no success. > > > > This the example for symbols, but how can I test conditions with a > symbol? > > (define (reply s) > > (cond > > [(symbol=? s 'GoodMorning) 'Hi] > > > > [( > > symbol=? s 'HowAreYou?) 'Fine] > > > > [( > > symbol=? s 'GoodAfternoon) 'INeedANap] > > > > [( > > symbol=? s 'GoodEvening) 'BoyAmITired])) > > > > ;function check-guess > > ;given number evaluate to one of three answers > > ;number -> number -> string > > > > tested without symbols and got it working so was trying to emulate this > with symbols > > > > (define (check-guess guess target) > > (cond > > [(< guess target) "Too Small"] > > [(= guess target) "Perfect"] > > [(> guess target) "Too large"] > > > > > > > > ;(define (check-guess guess target) > > ; (cond > > ; [(symbol=? 'guess (< guess target) 'Too small)] > > ; [(symbol=? 'guess (= guess target) 'Perfect)] > > ; [(symbol=? 'guess (> guess target) 'Too Large)])) > > > > ;(define (check-guess guess target) > > ; (cond > > ; [(symbol=? (< guess target) 'True 'Too Small)] > > ; [(symbol=? (= guess target) 'True 'Perfect)] > > ; [(symbol=? (> guess target) 'True 'Too Large)])) > > > > ;(define (check-guess guess target) > > ; (= s( < guess target)) > > ; (= s( = guess target)) > > ; (= s( > guess target)) > > ; (cond > > ; [(symbol= s 'true 'Too Small)] > > ; [(symbol= s 'true 'Perfect)] > > ; [(symbol= s 'true 'Too Large)])) > > > > ;(define (check-guess guess target) > > ; [(symbol=? guess (< target guess) "Too small")] > > > > > > _________________________________________________ > > For list-related administrative tasks: > > http://lists.racket-lang.org/listinfo/users > > Thanks getting some coffee into a checking it out now. Thanks for the tips.
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