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So I want to be a haskell wizard

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Hi,

I was wondering how one could write this scheme program in
a good haskell sense:

(define 'cons 0) ....

(define dispatch
        (vector cons
                un-cons
                car
                cdr
                set-car!
                set-cdr!
                pair?))

(lambda (<selector> . <arguments>)
(apply (vector-ref dispatch <selector>) <arguments>))))


After writing some 7 files of code (see below) I wondered if 
there are any better solutions:

-- code follows :

type ARGS = String 

readfunction :: [ARGS]->Int
readfunction s  = length s

writefunction :: [ARGS]->Int
writefunction s  = length s

type F = [ARGS]->Int
--type F = String->Int->[Char]
--type F = String->Int->[Int]

dispatchparser :: String -> [ARGS] -> F
dispatchparser msg args = case msg of
			"gnuvy" -> readfunction
			"foo" -> writefunction

main = do print "Foo" 
          print $ f([bar]) where
              bar = "foo"
              f = dispatchparser bar ["tully"]

-- code

type ARGS = String 

readfunction :: [ARGS]->Int
readfunction s  = length s

writefunction :: [ARGS]->Int
writefunction s  = length s

type F = [ARGS]->Int
--type F = String->Int->[Char]
--type F = String->Int->[Int]

dispatchparser :: String -> [ARGS] -> F
dispatchparser msg args = case msg of
			"gnuvy" -> readfunction
			"foo" -> writefunction

main = do print "Foo" 
          print $ f([bar]) where
              bar = "foo"
              f = dispatchparser bar ["tully"]

-- code

type ARGS = String 
--data ARGSDATA = Args String 
--		-- Args String 
--		-- String -- FIX
--		-- Int -- FIX
type ARGSLIST = [ARGS] 

readfunction :: ARGSLIST->Int
readfunction s  = length s

writefunction :: ARGSLIST->Int
writefunction s  = length s

type F = ARGSLIST->Int

dispatchparser :: String -> ARGSLIST -> F
dispatchparser msg args = case msg of
			"gnuvy" -> readfunction
			"foo" -> writefunction

main = do print "Foo" 
          print $ f([bar]) where
              bar = "foo"
              f = dispatchparser bar ["tully"]

-- code

type ARGS = String -- load at run-time 
--data ARGSDATA = ARGSDATA String 
--		-- Args String 
--		-- String -- FIX
--		-- Int -- FIX
type ARGSLIST = [ARGS] 

readfunction :: ARGSLIST->Int
readfunction s  = length s

writefunction :: ARGSLIST->Int
writefunction s  = length s

type F = ARGSLIST->Int

dispatchparser :: String -> ARGSLIST -> F
dispatchparser msg args = case msg of
			"gnuvy" -> readfunction
			"foo" -> writefunction

main = do print "Foo" 
          print $ f([bar]) where
              bar = "foo"
              f = dispatchparser bar ["tully"] -- ST-80 :-)


-- code

type ARGS = String -- load at run-time 
data ARGSDATA = ARGSDATA ARGS 
type ARGSLIST = [ARGSDATA] 

readfunction :: ARGSLIST->Int
readfunction s  = length s

writefunction :: ARGSLIST->Int
writefunction s  = length s

type F = ARGSLIST->Int

dispatchparser :: String -> ARGSLIST -> F
dispatchparser msg args = case msg of
			"gnuvy" -> readfunction
			"foo" -> writefunction

main = do print "Foo" 
          print $ f([argsdata2]) where
              bar = "foo"
              argsdata :: ARGSDATA
              argsdata = ARGSDATA "tully"
              argsdata2 :: ARGSDATA
              argsdata2 = ARGSDATA "tully2"
              f = dispatchparser bar [argsdata] -- ST-80 :-)

-- code


type ARGS = String -- load at run-time 
data ARGSDATA = ARGSDATA ARGS 
type ARGSLIST = [ARGSDATA] 

readfunction :: ARGSLIST->Int
readfunction s  = length s

writefunction :: ARGSLIST->Int
writefunction s  = length s

type F = ARGSLIST->Int

dispatchparser :: String -> ARGSLIST -> F
dispatchparser msg args = case msg of
			"gnuvy" -> readfunction
			"foo" -> writefunction

main = do print "Foo" 
          print $ f(argsdata2) where
              bar = "foo"
              argsdata :: ARGSLIST
              argsdata = [ARGSDATA "tully"]
              argsdata2 :: ARGSLIST
              argsdata2 = [ARGSDATA "tully2"]
              f = dispatchparser bar argsdata -- ST-80 :-)

-- code

readfunction :: Int->Int
readfunction i  = i
--equational readfunction = ReadFunction

writefunction :: Int->Int
writefunction i  = i
---equational writefunction = readfunction-- WriteFunction

--data F = Int

dispatchparser :: String -> (Int->Int) 
dispatchparser msg = case msg of
			"gnuvy" -> readfunction 
			"foo" -> writefunction 

main = do print "Foo" 
          print $ f(1) where
              f = dispatchparser "gnuvy"



TW

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So I want to be a haskell wizard Turtle Wizard <0wl256NOSPAM@gmail.com> - 2012-02-03 19:42 +0900
  Re: So I want to be a haskell wizard Paul Rubin <no.email@nospam.invalid> - 2012-02-03 16:09 -0800

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