>>> (foo 1) >> (foo 1) >>> (list 1 2) >> '(1 2) >> >> The output is not really consistent, in that foo is printed as a >> (user-level) >> constructor, but list is not. > > Well, `quote' is playing the role of constructor.
sure -- I get it, but it's surprising at first for students. At least it calls for an explanation. > >> For teaching, the problem with output '(1 2) is >> the need to explain (or try to ignore) the quote. > > PLAI uses `quote' for lists starting on page 8, so if you're teaching > with the book, it may not be worthwhile to avoid `quote'. Strictly speaking, it's not. It says "we can use the quote notation to simulate read." In the book, `read' comes with the need to start parsing. In my case, I have to start with 2 weeks of intro to Scheme before entering into PLAI (Scheme basics, higher-order programming, recursive definitions, design recipe). 2 weeks where I technically don't need `read' (or `quote') at all. Anyway, I agree this is not a big issue, I have dealt with it since plai's behavior changed, a few semesters ago. It's just now that I'm writing some lectures notes (with Scribble!) in spanish for the 2-week crash course before PLAI, that I realized that I was missing the good old behavior. > I think my students has had little trouble with `quote'. In contrast, > in the bad old days when the `quote' was missing --- so that `(list 1 > 2)' printed as just `(1 2)' --- students had a difficult time with the > difference between expressions and printed values. I certainly agree with that. > [...] Right -- not until we fix constructor-style printing. Ok ;-) -- Éric _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
