Definition of fix lacks commentary
In Data.Function
,
fix :: (a -> a) -> a
fix f = let x = f x in x
It is not immediately obvious why it is defined like this, rather than the more natural
fix f = f (fix f)
There are very good reasons for this; notably, it allows for the definition of circular data structures. But there should be a comment explaining this, preferably in the Haddocks.
Trac metadata
Trac field | Value |
---|---|
Version | 7.11 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Core Libraries |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | core-libraries-committee@haskell.org |
Operating system | |
Architecture |