What is wrong with this list comprehension code?
- by suresh
My aim is to list all elements of the array a whose values are greater than their index positions. I wrote a Haskell code like this.
[a|i<-[0..2],a<-[1..3],a!!i>i]
When tested on ghci prelude prompt, I get the following error message which I am unable to understand.
No instance for (Num [a]) arising from the literal 3 at <interactive>:1:20 Possible fix: add an instance declaration for (Num [a])