Op 11-4-2012 15:10, Stephen Bloch schreef:
On Apr 11, 2012, at 7:39 AM, Roelof Wobben<r.wob...@home.nl> wrote:
But I see something strange, Both check-expect of the function width gives as
output 18.
But I expect that on a empty (editor-pre verwerker) gives as output 0.
Am I mistaken or is there something wrong in my functions ?
Yes, there's something wrong with your width function. It's nothing subtle or
complicated; you can figure it out just by looking at the two-line definition
of that function.
In addition, the contract of the function is wrong: you say it takes in an
image, but your test cases give it an editor instead.
More broadly, you're doing the whole problem the hard way. Why do you need to
know the width of anything? I would do this whole problem without an
image-width, without arithmetic, without a place-image, using the functions in
the 2htdp/image library.
Stephen Bloch
sbl...@adelphi.edu
Oke,
I changed the contract to Editor -> Number.
When I change the make-editor function the value changed.
So I think the check-expect is wrong but I have no clue how to change it.
I find the way with overlay and beside more the hard way. I have puzzled
a lot of time with it without success and this solution cost me a half a
hour.
Roelof
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