[Haskell-cafe] The instability of Haskell libraries

[David Menendez]

On Fri, Apr 23, 2010 at 10:11 PM, John Goerzen <jgoerzen at complete.org> wrote:
> Don Stewart wrote:
>>
>> Oh, the Platform has very strict standards about APIs,
>>
>> When a package may be added:
>>    http://trac.haskell.org/haskell-platform/wiki/AddingPackages
>
> That looks like a very solid document.  Does it also apply when considering
> upgrading a package already in the platform to a newer version?
>
> Also, I notice that http://haskell.org/haskellwiki/Package_versioning_policy
> does not mention adding new instances, which caused a problem in the past.
>  I would argue that this ought to mandate at least a new A.B.C version, if
> not a new A.B.

Adding or removing instances requires a new major version. See section 2:

| If any entity was removed, or the types of any entities or the definitions of
| datatypes or classes were changed, or instances were added or removed,
| then the new A.B must be greater than the previous A.B.

-- 
Dave Menendez <dave at zednenem.com>
<http://www.eyrie.org/~zednenem/>