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From: mmh@cs.qmw.ac.uk (Matthew Huntbach)
Newsgroups: comp.edu
Subject: Re: Pascal as a first Language
Message-ID: <2560@sequent.cs.qmw.ac.uk>
Date: 25 Jul 90 13:44:27 GMT
References: <24994.26a7079d@kuhub.cc.ukans.edu>
Reply-To: mmh@cs.qmw.ac.uk (Matthew Huntbach)
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In article <24994.26a7079d@kuhub.cc.ukans.edu> cs300@kuhub.cc.ukans.edu writes:
>Some of my reasons:
>The main technique to learn is abstract data types and modularity.
>Pascal adds all kinds of syntactic overhead to the structuring of
>data (e.g. "." vs "[]" for essentially the same thing: compound data)
I think the distinction between arrays - which are indexed -
and records - which are not - is an important one.
Of course, you should encourage the use of syntactic structures
ONLY within procedures and functions which implement the
abstract data types. In this way, the language syntax becomes a
minor detail anyway.

>Pascal forces everything to be declared globally if it is to retain its
>value (i.e., there is no private data)
I think this is acceptable for a first programming course.
Introducing private data at this stage is only overloading the
students. They will only get to see the benefit of private data
as a result of experience, so it is better introduced in the
second programming course.

>Pascal punishes one for recursion (unless tail recursion is implemented)
At the first programming course stage you shouldn't be worrying
too much about efficiency. Students are unlikely to be writing
programs where the inefficiency of Pascal's recursion
implementation notices.

>Procedures and functions are not first class data items and hence only
>a small subset of programming techniques is learned.
The use of higher-order functions often strikes me as a dirty
programming trick, akin to the use of gotos. I don't think I
have ever had to use it in ten years of writing programs. I
have seen too many "clever" programs which make unnecessary use
of procedures and functions as first class data items. I
think it is best not covered at the initial stage.

>Polymorphism is only difficultly achieved to a partial degree.
Again, while polymorphism has benefits, at the initial stage
there are positive benefits in NOT using it. Students ought to
be thoroughly aware that a "list of X" is not of the same type
as a "list of Y".
>
>Now, granted, some of these topics aren't always suitable for a first course,
>but the teaching of Pascal means that in order to learn them, one has to drop
>pascal (and all the bad habits its taught) and pick up a reasonable language.
Any CS student worthy of the name ought to have no difficulty
in switching languages.

I don't think Pascal is perfect, but it's a reasonable
compromise between various conflicting requirements. The
important thing is to stress that it is being used as a
teaching tool - making sure that students are aware you are
teaching the principles of good programming, not "coding in
Pascal".

My main concern about the language is that many students coming
to first programming courses already have a lot of experience
with computers in high schools or as hobbyists. It is too easy
to carry on bad programming techniques into Pascal. So I agree
it may be good to shock them by introducing a completely
different sort of language, either functional or logic.

Matthew Huntbach