[GHC] #11065: Outdated documentation for foldl and friends

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Mon Dec 14 15:39:07 UTC 2015


#11065: Outdated documentation for foldl and friends
-------------------------------------+-------------------------------------
        Reporter:  goldfire          |                Owner:  bgamari
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.0.1
       Component:  Documentation     |              Version:  7.10.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by bgamari):

 * owner:   => bgamari


Old description:

> Straight from `Data.Foldable`, here is the documentation for `foldl`:
>
> {{{
>     -- | Left-associative fold of a structure.
>     --
>     -- @'foldl' f z = 'Prelude.foldl' f z . 'toList'@
> }}}
>
> But, of course, `Prelude.foldl` is the same `foldl`!
>
> There are other functions with similar problems.
>
> When revising these, please put in (back?) examples of how these work, at
> least on lists. I've been doing functional programming for some time, and
> I still like to look at examples to make sure that I'm getting my `foldl`
> and `foldr` straight. Maybe it's because my brain is small, but we don't
> want to exclude people with small brains!

New description:

 Straight from `Data.Foldable`, here is the documentation for `foldl`:

 {{{#!hs
 -- | Left-associative fold of a structure.
 --
 -- @'foldl' f z = 'Prelude.foldl' f z . 'toList'@
 }}}

 But, of course, `Prelude.foldl` is the same `foldl`!

 There are other functions with similar problems.

 When revising these, please put in (back?) examples of how these work, at
 least on lists. I've been doing functional programming for some time, and
 I still like to look at examples to make sure that I'm getting my `foldl`
 and `foldr` straight. Maybe it's because my brain is small, but we don't
 want to exclude people with small brains!

--

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11065#comment:1>
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