Re: [Haskell-cafe] separate input calculation output

Thomas Engel writes:

My problem is: How can I get the input values into the calculations and back the result to the output.

In an other language I would use global variables for this.

That would be bad style.

An other point is that I want to separate the input from the calculations and the output.

So what should I use in haskell?

I think your pseudocode is right on track.

inputvalues :: IO ()

The most obvious way to do it would be to define data Input = ... data Output = ... input_values :: IO Input calculate :: Input -> Output ouput_values :: Output -> IO () then: main = do i <- input_values let o = calculate i output_values o or: main = output_values . calculate =<< input_values -k -- If I haven't seen further, it is by standing in the footprints of giants