Can anyone help with the following:
How can you force a 'sequence' of evaluation in a function. The code listed
below causes both prompts for numbers to be printed before you get a
chance to enter the first number. (Are irrefutable patterns the answer !!!)
Also, how can you stop quotes being printed after a string, using printIO.
P.S What is the difference between `thenIO_` and `thenIO`
`bindIO_` and `bindIO`.
Aiden McCaughey
University of Ulster
> module Main where
> import PreludeGlaIO
> readStringIO :: IO [Char]
> readStringIO = readChanIO stdin `bindIO` \x ->
> returnIO (head (lines x))
> promptInputIO :: [Char] -> IO [Char]
> promptInputIO p = printIO p `thenIO_`
readStringIO
> readIntIO :: IO Int
> readIntIO = readStringIO `bindIO` \x ->
> returnIO (read x::Int)
> mainIO = printIO "Enter First Number : " `thenIO_`
> readIntIO `bindIO` \x ->
> printIO "Enter Second Number : " `thenIO_`
> readIntIO `bindIO` \y ->
> printIO (x-y)
