#3480: Easily make Typeable keys pure, so that Typeable can be handled
efficiently across communications
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Reporter: guest | Owner:
Type: task | Status: new
Priority: normal | Milestone: 7.2.1
Component: libraries/base | Version:
Resolution: | Keywords: Typeable, efficiency
Testcase: | Blockedby:
Difficulty: Unknown | Os: Unknown/Multiple
Blocking: | Architecture: Unknown/Multiple
Failure: None/Unknown |
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Changes (by lealanko):
* cc: la@… (added)
* status: closed => new
* resolution: fixed =>
Comment:
Unfortunately the new {{{TypeRepKey}}} type is abstract and provides no
operations apart from {{{Eq}}} and {{{Ord}}} instances. Hence, there is
still no way to write a type representation into a file or across the
wire. Jush {{{show}}}ing a {{{TypeRep}}} won't cut it, since that loses
the distinctions between similarly named types in different modules.
So, I think we need a {{{Show}}} instance for {{{TypeRepKey}}}, or better
yet, a {{{Binary}}} instance. Moreover, a non-deprecated pure function
{{{TypeRep -> TypeRepKey}}} is in place, since the keys have an actual use
as a compact, efficient, and serializable injection of the typereps.
Alternatively, the {{{Show}}} instance of {{{TypeRep}}} could be made
injective by printing out the package and module.
(I intended to open a new ticket, I hope it's ok that I reopen this old
one instead.)
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3480#comment:10>
GHC <http://www.haskell.org/ghc/>
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