[plt-scheme] Error...

From: John Clements (clements at brinckerhoff.org)
Date: Wed Dec 14 12:02:26 EST 2005

On Dec 14, 2005, at 6:45 AM, Paulo Jorge Matos wrote:

> 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.

I'm 100% with you until that last sentence.  Strike "R5RS" and  
replace with "Beginning Student."  The beginning student language is  
designed for PRECISELY the reasons you describe.

In fact, it supports your plan far better than R5RS.  You're using  
R5RS to mean "no libraries," but the other half of the coin is "no  
internal define, no implicit begin, etc. etc.", and it is these  
simplifications that beginning student leverages in order to provide  
better error messages and a better learning environment.

Is there some reason that DrScheme's beginning student language is  
not a good choice for your class?

John Clements

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 2430 bytes
Desc: not available
URL: <http://lists.racket-lang.org/users/archive/attachments/20051214/0a1f47da/attachment.p7s>

Posted on the users mailing list.