Proposal: Make `NFData` a fundamental/primitive type-class (by making `deepseq` a GHC-boot package)
marlowsd at gmail.com
Thu Aug 25 12:04:43 CEST 2011
On 25/08/2011 08:12, Simon Peyton-Jones wrote:
> | Make `NFData` a fundamental/primitive type-class
> | (by making `deepseq` a GHC-boot package)
> The goals are good, but I don't follow the proposed design. In particular, why does the deepseq package need to be in base?
The proposal is to make deepseq a boot package, not to move anything
> In principle, you can do this:
> * Implement deepseq
> * Add instances for GHC types and container types; these instances
> wouldn't be orphans because they'd be in the module defining the
> NFData class
That's what we have right now, the problem is that deepseq can't define
a good instance for NFData Map, because it can't see enough of the
internals of Map.
> The main objection seems to be this:
> * deepseq would thereby depend on 'containers' (say), whereas a random
> customer of deepseq might find that odd. And it might increase the size
> of his binaries.
> The solution to that is to make containers depend on deepseq. That would induce the inverse dependency: every user of containers would get deepseq willy-nilly. Perhaps that is less bad.
> And it would make 'deepseq' into a GHC boot package, which is probably fine.
Exactly, that's the proposal!
(+1 from me, BTW)
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