Op 11-4-2012 18:03, Roelof Wobben schreef:
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
Nobody who can give me a tip what's wrong with the function.
Roelof
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