On Thu, May 13, 2010 at 04:43:26PM +0100, Stephen Tetley wrote: > Hi Eugene > > You don't need to supply all the arguments to a constructor at once: > > makeWithOne :: String -> (String -> String -> Object) > makeWithOne s1 = \s2 s3 -> Object s1 s2 s3 > > -- or even: > -- makeWithOne s1 = Object s1 > > This builds a higher-order function that can be applied later to two > Strings to finally make the Object.
Hello, Stephen!
Well, that's true, but I don't really know the order of incoming data. So for
constructor MyObject { prop1, prop2, prop3 :: String } there can be the cases
of order
prop1
prop2
prop3
prop3
prop2
prop1
prop1
prop3
prop2
...
so I may need to initialize prop1, then prop3, and finally prop2 to make
instance of MyObject. And similarly for another cases.
I don't see any easy solution for now except sort name-value pairs in some
pre-defined order, and then use something like
> props :: [(String,String)]
> result = MyObject (props' !! 0) (props' !! 1) (props' !! 2)
> where
> props' = map snd props
which looks ugly and involves some additional calculations for sorting.
--
Eugene Dzhurinsky
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