[plt-scheme] Error...

From: Paulo Jorge Matos (pocmatos at gmail.com)
Date: Wed Dec 14 09:45:35 EST 2005

On 14/12/05, Shriram Krishnamurthi <shriram at gmail.com> wrote:
> > However, I forgot (error ...) was not in R5RS and I
> > was thinking about providing them a way to notice users of errors when
> > they happen.
> This is exactly what we mean when we say R5RS is not a programming
> language.  Programming languages are sensitive to the fact that programs
> may contain errors.  Specification languages, in contrast, assume that they
> are describing a ground truth.  R5RS is a specification language for algorithms.
> Please don't put your students through the misery of programming in R5RS.
> What point are you trying to make?  How are you doing anything but giving
> the impression that Scheme is a brain-dead language that lacks even the most
> basic capabilities of other languages they have seen?

HI Shriram,

thanks for your comments. This course is for students learning on how
to program. Most have never seen anything in programming before. We
teach them recursive procedures, recursive and iterative processes,
working with numbers, lists, vectors, mutable structures and
approaches to expression evaluation. It's not much but most of them
lack training in programming. All of the course project has to do with
working with nested lists, so we would like to make them define all
those tiny procedures we are used to work on every day programming.
That's why we make them work with R5RS. However, during the semester
we have no trouble they use other languages.

Still, one problem we face is that no student gets back to program in
Scheme during their degree so they get to think that Scheme is all
they have been taught, i.e., mostly nothing! This year I've written
some challeging exercises and during classes I talk with them about
other things they'll never learn about in Scheme if they don't get
back to it by themselves. Somehow I think it's working with some
students that have already contacted me since they want to learn more
about other 'stuff' in scheme like web programming. Still, I guess
higher education in Portugal has still much to evolve, since they have
a very heavy schedule leaving them no time at all to do 'programming'
at home or to work on other programming assignments out of classes.
Although some students are lazy... by nature.... others are simply
restricted to programming done during classes or weekends due to
pressure put on them by heavy schedule with classes which probably
will have no interest at all for their future. But anyway, that is a
problem I cannot solve at all, but with time I hope I can minimize it!

Paulo Matos

> Shriram

Paulo Jorge Matos - pocm at sat inesc-id pt
Web: http://sat.inesc-id.pt/~pocm
Computer and Software Engineering

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