Difference between revisions of "DDC/PolymorphicUpdate"
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(get, set) |
(get, set) |
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</haskell> |
</haskell> |
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| + | This function allocates a box which can store a value and returns a tuple of functions which can be used to get and set that value. |
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Revision as of 06:17, 19 March 2008
Get/Set
Consider the following function:
makeGetSet :: a -> (() -> a, a -> ())
makeGetSet x
= do box = Just x
get () = case box of { Just z -> z; }
set z = box#x #= z
(get, set)
This function allocates a box which can store a value and returns a tuple of functions which can be used to get and set that value.