On Fri, 2006-01-13 at 20:52 +0000, Ross Paterson wrote: > On Fri, Jan 13, 2006 at 08:25:46PM +0000, Duncan Coutts wrote: > > On Fri, 2006-01-13 at 13:53 +0000, Ross Paterson wrote: > > > Have a look at Data.Sequence (in CVS/darcs version), docs at > > > > > > http://www.haskell.org/ghc/dist/current/docs/libraries/base/Data-Sequence.html > > [...] > > It's probably too much to ask, but here's a question: > > > > would it be possible to provide an operation that gives a left or right > > view from looking up an index. Say: > > > > viewrFromIndex :: Seq a -> Int -> ViewL a > > viewlFromIndex :: Seq a -> Int -> ViewR a > > > > The library currently provides views for the each end of the sequence. > > > > viewl :: Seq a -> ViewL a > > viewr :: Seq a -> ViewR a > > > > I suppose this would be a zipper-like iterator for the sequence? > > I'm not entirely sure what these are intended to do, but can't you > just compose view[lr] with take/drop?
Oh yes, so you can. That's very neat. Thanks. Duncan _______________________________________________ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
