Changes between Version 8 and Version 9 of FlexibleContexts


Ignore:
Timestamp:
Mar 31, 2006 10:39:43 PM (9 years ago)
Author:
ross@…
Comment:

note on derived instances

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  • FlexibleContexts

    v8 v9  
    5656 * is required by OverlappingInstances
    5757
     58In GHC and Hugs, the contexts of derived instances are fully reduced, so the following instance is allowed only if the instance {{{Eq Bar}}} is in scope:
     59{{{
     60data Foo = K Bar deriving Eq
     61}}}
     62
    5863== Pros ==
    5964 * useful with FlexibleInstances
     
    6166== Cons ==
    6267 * complicated context reduction story
    63  * deferred error checking
     68 * deferred error checking (FunctionalDependencies can ameliorate this)