from hell to paradise ; ; ; was: [plt-scheme] Prereqs for robotic programming

From: Jos Koot (jos.koot at
Date: Tue Feb 17 20:02:59 EST 2009

May be the issue is that FP requires additional layers of abstraction. That 
frightens lots of people. I remember well how much time I had to spend in 
order to give my students a grasp of first order abstraction. My personal 
view is, as Matthias Felleisen (thanks) once pointed out to me, of another 
universe, namely that CS students, or even students only to be tought 
programming (the borderline is not sharp I think) should first master a 
substantial part of mathematics in order to grasp levels of abstractions. I 
think the two can be combined, though. A good correlation and 
synchronization between mathematics classes and parallel computer science 
classes can be helpfull. They may even be integrated one into the other. My 
point of view is that programming requires the development of the ability to 
discern levels of abstraction and the discipline not to confuse these 

Please don't interpret this wrongly. I do admire the succesful approach of 
HtDP such as to present students with *interesting* problems while 
nevertheless presenting a disciplined approach to programming.

Nowadays students require courses to be attractive. In a number of countries 
making courses attractive, even to the dispence of quality, is enhanced by a 
financial system that grants universities money based on the ratio between 
the number of incoming students and the number of those that do graduate. I 
have seen a number of examples where this strategy fails. It may easily lead 
to relaxation of the demands imposed on students. But allas, this seems to 
be the universe we are living in. I want another universe. A university 
should be awarded for not letting pass students that do not qualify. It 
should be awarded for the quality of the graduates rather than the number of 
graduates. An unreal universe, I know, but it is worth to strive for an 
ideal even if beforehand we know that not all of this ideal can be 

----- Original Message ----- 
From: "Grant Rettke" <grettke at>
To: "Marco Morazan" <morazanm at>
Cc: "PLT List" <plt-scheme at>; "Matthias Felleisen" 
<matthias at>
Sent: Wednesday, February 18, 2009 12:51 AM
Subject: Re: from hell to paradise ; ; ; was: [plt-scheme] Prereqs for 
robotic programming

> On Tue, Feb 17, 2009 at 5:25 PM, Marco Morazan <morazanm at> wrote:
>>>> But people are motivated toward pleasure and away from pain, so if 
>>>> learning
>>>> FP is going to cause too much pain, it's going to be a non starter.
>>> Yes it is painful.
>> I am always shocked to hear stuff like this.
> When I feel shocked at what someone says; it is often an opportunity
> for me to get to the root of a perspective very different from my own.
> It is just a feeling; you know that they can't be trusted.
> I don't think what is going on here is very shocking, though. Anything
> different from the mainstream will be more difficult to learn just
> because it is different.
> Now throw on top of that what is considered to me normal, or rather
> what is considered not to be normal in the mainstream:
> Normal: Object orientation, Design Patterns, C like languages, no
> depth or attention to detail, over complexity
> Abnormal: HtDP, SICP, attention to detail, thoughtful action, simplicity
> The very traits that are lauded in the mainstream offer little help in
> seeing the value of FP; or really anything for that matter.
> That said, there are a lot of mainstream books that are tailored to
> "draw in the masses" to OO. Kathy Sierra's "Head First" books for
> example are very appealing to the large. Also Peter Siebel's
> "Practical Common Lisp" or the "Real World Haskell" book are what
> people want to see so they feel like they are "doing something
> valuable" with what they learn. I don't see that in the FP world.
> Another example is showing the value of "pure functional programming".
> Other than HtDP, I have yet to be able to find a book that teaches how
> to, and the value of, designing purely functional programs. I have
> asked just about everyone I could find and there is still only one
> that I can point too.
> It is all about marketing. It isn't about real value; it is about
> perceived value.
> It would take a FP person writing a hot book and speaking at
> conferences and doing all sorts of things to generate hype. That is
> how languages "win".
>> Functional programming
>> exacts a small intellectual price for a great deal of power that
>> *most* when they discover it feel relieved and a sense of
>> satisfaction.
> Agreed. I feel the same way.
>> Yet the myth -- and let's be frank it is a myth -- that
>> functional programming is hard persists.
> Compared with the mainstream tracks; it has a higher barrier to entry.
>> Seriously, what is painful about it? Is it painful not to have a
>> mangled syntax? Is it painful to encourage the use of recursion?
>> Really, c'mon! Is it painful for functions to be first-class? Is it
>> painful not to encourage the use of sequencing and
>> mutation/assignment? Is it painful not to have "for" and "while" as
>> keywords? Is it painful not to think of state all the time? Is it
>> painful not to have to manipulate pointers? Is it painful for the
>> language to properly implement tail calls? Is referential transparency
>> painful -- most of my students are shocked when I point out to them
>> that in, say, Java (pick any language that encurages assignment) that
>> f(x) == f(x) is not always true, which suggest huge gaps in their
>> education when they learned Java --? Is having macros or continuations
>> painful?
> Strawmen: that is not the point.
>> I am not being cynical here. I know that many pick up bad habits that
>> become part of muscle memory and then may feel lost at sea using a
>> different programming language. Is that a short coming of functional
>> programming?
> It doesn't matter whose fault it is; but what matters is how easy you
> make it for these lost souls to be saved.
>> Would any of those lost at sea feel more comfortable
>> coding in Prolog? Would a Cobol programmer feel more comfortable
>> programming in Java? Perhaps, it is a shortcoming of our education and
>> not of functional programming.
> No. No. It doesn't matter. What matters is how you sell it.
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