[racket] confused beginner

That was the problem, thanks Robby!  I guess ubuntu's apt repo's not up to
date or something.

Andrew

On Sat, Oct 4, 2014 at 2:38 PM, Robby Findler <robby at eecs.northwestern.edu>
wrote:

> Are you sure you have a recent version of racket? I wonder if you're
> looking at the docs for the latest release (on docs.racket-lang.org)
> but you have an older release where you're trying things out.
>
> Note that you can look at your local docs and those docs should match
> up to your local installation.
>
> Robby
>
>
> On Sat, Oct 4, 2014 at 2:32 PM, Andrew Ulrich
> <andrewsotheraccount at gmail.com> wrote:
> > Ok, I'm stuck again:
> > I'm trying to use place-image, but it keeps saying
> > place-images: unbound identifier in module in: place-images
> >
> > It doesn't even seem to work with the example code in the docs found at:
> >
> http://docs.racket-lang.org/teachpack/2htdpimage.html?q=overlay#%28def._%28%28lib._2htdp%2Fimage..rkt%29._place-images%29%29
> >
> > Here's what I think the docs say the code is:
> > #lang racket
> > (require 2htdp/universe)
> > (require 2htdp/image)
> > (require lang/posn)
> > (place-images
> >    (list (circle 4 "solid" "blue")
> >          (circle 4 "solid" "white")
> >          (circle 4 "solid" "white")
> >          (circle 4 "solid" "white"))
> >    (list (make-posn 18 20)
> >          (make-posn 0 6)
> >          (make-posn 14 2)
> >          (make-posn 8 14))
> >    (rectangle 24 24 "solid" "goldenrod"))
> >
> > But like I said, I get the error.  I'm trying to use place-images to
> place a
> > bunch of sprite images on a scene for a simple video game.  I'm assuming
> > place-images the best way to do that.
> >
> > Thanks in advance for helping me out.  I know it's basic stuff.
> >
> > On Sat, Oct 4, 2014 at 9:04 AM, Andrew Ulrich
> > <andrewsotheraccount at gmail.com> wrote:
> >>
> >> Aha, great! Thanks guys!
> >>
> >> Andrew
> >>
> >> On Sat, Oct 4, 2014 at 8:54 AM, Jens Axel Søgaard <
> jensaxel at soegaard.net>
> >> wrote:
> >>>
> >>> Hi Andrew,
> >>>
> >>> To add what Matthias say, if you need a "function version" of bitmap,
> >>> you can use bitmap/file instead.
> >>>
> >>>     (require 2htdp/image)
> >>>     (define path-stringy "images/some.png")
> >>>     (bitmap/file path-stringy)
> >>>
> >>> Note that I changed (path-stringy) to path-stringy.
> >>>
> >>> /Jens Axel
> >>>
> >>>
> >>>
> >>>
> >>> 2014-10-04 15:48 GMT+02:00 Matthias Felleisen <matthias at ccs.neu.edu>:
> >>> >
> >>> > What you used is called a "computed string" that is, you expect
> bitmap
> >>> > to evaluate the argument path-stringy to a string.
> >>> >
> >>> > But, in BSL, bitmap expects to be handed a literal string constant
> (or
> >>> > a module path):
> >>> >
> >>> > ---------------------------------------------------------------------
> >>> > (require 2htdp/image)
> >>> >
> >>> > ;; with a module path
> >>> > (bitmap 2htdp/planetcute/character-cat-girl.png)
> >>> >
> >>> > ;; with a fixed string
> >>> > (bitmap
> >>> >
> "plt/pkgs/htdp-pkgs/htdp-lib/2htdp/planetcute/character-cat-girl.png")
> >>> > ---------------------------------------------------------------------
> >>> >
> >>> > Both of these will succeed and retrieve the cat girl from the Planet
> >>> > Cute collection that comes with Racket -- Matthias
> >>> >
> >>> >
> >>> >
> >>> >
> >>> > On Oct 4, 2014, at 9:36 AM, Andrew Ulrich wrote:
> >>> >
> >>> >> Hi, I've got a really simple problem, I think.  Why is it that when
> I
> >>> >> try to do the following:
> >>> >>
> >>> >> (require 2htdp/image)
> >>> >> (define path-stringy "images/some.png")
> >>> >> (bitmap (path-stringy))
> >>> >>
> >>> >> I get the following error:
> >>> >>  bitmap: expected the argument to specify a local path (via a
> string)
> >>> >> or a module path (e.g. `icons/b-run.png') in: (bitmap
> (path-stringy))
> >>> >>
> >>> >> I mean, shouldn't path-stringy evaluate to a string before it's
> passed
> >>> >> into bitmap?  If not, then how do I use bitmap for anything dynamic?
> >>> >>
> >>> >> Thanks,
> >>> >> Andrew
> >>> >> ____________________
> >>> >>  Racket Users list:
> >>> >>  http://lists.racket-lang.org/users
> >>> >
> >>> >
> >>> > ____________________
> >>> >   Racket Users list:
> >>> >   http://lists.racket-lang.org/users
> >>>
> >>>
> >>>
> >>> --
> >>> --
> >>> Jens Axel Søgaard
> >>
> >>
> >
> >
> > ____________________
> >   Racket Users list:
> >   http://lists.racket-lang.org/users
> >
>
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