Haskell: Variable not in scope?

Question

I'm trying to run the following code to get subsets of k-elements but getting variable not in scope:ksubsets Not exactly sure whY?

Code:

subsets :: [a] -> [[a]]
subsets [] = [[]]
subsets (x:xs) = [zs | ys <- subsets xs, zs <- [ys, (x:ys)]]


ksubsets k xs = [ys | ys<-subsets xs, length ys==k]

and you did use a file to specify these functions? Or did you load these in ghci itself, since an :r will indeed clean the memory, and thus remove the ones not in the file. — willeM_ Van Onsem
– willeM_ Van Onsem, Commented Oct 6, 2019 at 22:03
ghci> :{, then copy-paste your lines, then ghci> :}. (that's multi-line input mode) — Will Ness
– Will Ness, Commented Oct 6, 2019 at 22:10
you probably have some mix-up. carefully create new file, and load it. :) — Will Ness
– Will Ness, Commented Oct 6, 2019 at 22:13

developer_hatch · Accepted Answer · 2019-10-07 01:24:06Z

1

Summarizing the comments, and possible problems and solutions:

There are no errors in your code, you can even try it online here
If you are using a text editor, check if you save your changes.
run ghci, and load your file

$> ghci

Prelude> :l path/to/your/file.hs
It should compile fine.

edited Oct 7, 2019 at 1:24

answered Oct 7, 2019 at 1:12

developer_hatch

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1 Comment

STOPIMACODER Over a year ago

Thank you for the summary! Another problem i don't know how to solve, how would i filter subsets based on length of k elements? AGain, Thanks!

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