Wy not load the list as program? E.g.
list1 =
["word1"
,"word2"
,"word3"
]
list2 = words "word1 word2 word3"
list3 = words
"\
\ word1\
\ word2\
\ word3\
\"
John Atwood
-------------------------------------
Lars Lundgren wrote:
>
> On Wed, 26 Apr 2000, Hamilton Richards wrote:
>
> > The Gofer prelude had a function
> >
> > openfile :: String -> String
> >
> > which mapped file path names to strings containing the named files' contents.
> >
> > The Hugs98 Prelude doesn't seem to have anything like that function.
> > Instead, it has things like
> >
> > readFile :: String -> IO String
> >
> > Why would I want openfile instead of readFile? The problem in which the
> > need for openfile arose is this:
> >
> > I want to load a binary search tree and a list with
> > words read from a file, and then perform, interactively,
> > several tests comparing the cost of searching the
> > tree with that of searching the list. In addition to
> > performing the tests interactively, I want to separate
> > the cost of searching the list and the tree from the
> > cost of constructing them.
> >
> > In order for the list and the tree to be used in several successive
> > command-line evaluations without being reconstructed each time, they must
> > be named globally. This is no problem with openfile, but readFile forces
> > their names to be local to an IO command.
> >
>
> Why is this a problem? After all, the names ARE dependent on IO.
>
> > Can anyone suggest a solution?
> >
>
> I do not understand the problem.
>
> Is it something like this you want?
>
> parseTree :: String -> Tree
> parseList :: String -> List
>
> buildTree:: IO Tree
> buildTree = do f <- readFile "thetree"
> return (parseTree f)
>
> buildList:: IO List
> buildList = do f <- readFile "thelist"
> return (parseList f)
>
> test :: IO()
> test = do tree <- buildTree
> list <- buildList
> dowhateverYouwant_interactive_or_not tree list
>
>
> dowhateverYouwant_interactive_or_not :: Tree -> List -> IO()
>
>
> /Lars L
>
>
>
>
>
