Difference between revisions of "Talk:GHC/Type families"
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+ | How does this change now that GHC 6.8.1 is out? [[User:MathematicalOrchid|MathematicalOrchid]] 12:55, 11 November 2007 (UTC) |
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− | I believe the instance declaration: |
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− | instance GMapKey Int where |
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− | data GMap Int v = GMapInt (Data.Map.Map Int v) |
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− | empty = GMapInt Data.Map.empty |
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− | lookup k (GMapInt m) = Data.Map.lookup k m |
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− | insert k v (GMapInt m) = GMapInt (Data.Map.insert k v m) |
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− | instance GMapKey Int where |
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+ | In 4.3.2 Examples |
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− | data GMap Int v = GMap Int (Data.Map.Map Int v) |
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+ | |||
− | empty = GMap Int Data.Map.empty |
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+ | module GMap (GMapKey(..), GMap(..)) where...: As before, but also exports all the data constructors GMapInt, GMapChar, GMapUnit, GMapPair, and GMapUnit. |
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− | lookup k (GMapInt m) = Data.Map.lookup k m |
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+ | |||
− | insert k v (GMapInt m) = GMap Int (Data.Map.insert k v m) |
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+ | |||
+ | module GMap (GMapKey(..), GMap(..)) where...: As before, but also exports all the data constructors GMapInt, GMapChar, GMapUnit, GMapPair, and GMapEither. |
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+ | |||
+ | Paragraph 6 is a copy of Paragraph 4 except Collects is used. |
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+ | In 7.3 Equality constraints |
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+ | Why was `<hask>~</hask>' used, instead of `<hask>=</hask>` ? |
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+ | [[User:StefanLjungstrand|StefanLjungstrand]] 19:55, 12 December 2007 (UTC) |
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+ | == GADT syntax in Type Families == |
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+ | GADT syntax is allowed nowadays, as per http://www.haskell.org/ghc/docs/latest/html/users_guide/type-families.html#data-instance-declarations. |
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+ | An update of the Wiki also would be in place. |
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+ | [[User:obscaenvs|Fredrik Carlén]] |
Latest revision as of 09:27, 12 July 2012
How does this change now that GHC 6.8.1 is out? MathematicalOrchid 12:55, 11 November 2007 (UTC)
In 4.3.2 Examples
module GMap (GMapKey(..), GMap(..)) where...: As before, but also exports all the data constructors GMapInt, GMapChar, GMapUnit, GMapPair, and GMapUnit.
should probably be:
module GMap (GMapKey(..), GMap(..)) where...: As before, but also exports all the data constructors GMapInt, GMapChar, GMapUnit, GMapPair, and GMapEither.
Paragraph 6 is a copy of Paragraph 4 except Collects is used.
In 7.3 Equality constraints
Why was `~
' used, instead of `=
` ?
StefanLjungstrand 19:55, 12 December 2007 (UTC)
GADT syntax in Type Families
GADT syntax is allowed nowadays, as per http://www.haskell.org/ghc/docs/latest/html/users_guide/type-families.html#data-instance-declarations.
An update of the Wiki also would be in place. Fredrik Carlén