[Haskell-cafe] Re: Tutorial uploaded

[John Hughes]

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>Message: 1
>Date: Wed, 21 Dec 2005 10:48:08 +0000
>From: Robin Green <greenrd at greenrd.org>
>Subject: Re: [Haskell-cafe] Re: Tutorial uploaded
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>>Beginners should start with non-monadic functions in order to later avoid
>>IO in their functions whereever possible.
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>Whilst localising IO to a small part of the program is generally a good 
>idea, beginners should not be scared off by the thought that IO in 
>Haskell is so hard it has to be covered on page 94. This is not the 
>case. It should be introduced on page 1.
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>If people want Haskell to be treated as a practical language, not just 
>something for doing academic teaching and research with, it should be 
>taught as a practical language - which means that things like IO and 
>space/time usage come to the forefront.
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Couldn't agree more. I show my students IO in the first lecture of their 
first programming
course in the first term of their first year. A few lectures later I 
discuss it in more detail,
and tell to think of an IO a as instructions on a piece of paper to 
produce an a. My students
have no difficulty understanding the difference between being given 500 
crowns (a value),
and being given my ATM card and code with instructions how to work an 
ATM! Haskell
IO is mystifed far too often in my opinion--it needn't be hard at all.

John