It is apparently the syntax-directed editor that was the problem for Jack
Campin:
> The structure editor is why I gave up on ABC. I was trying to use it on
> the Mac, where the editor is tightly coupled to the interpreter (you can't
> use an editor of your own choice).
The fact that you can't use another editor on the Mac was not a design aim, but
a result of lack of resources. On the Unix version of ABC you *can* use the
editor of your choice. If anyone has the motivation and resources, they are
welcome to add the option of using another editor, the rest of the system
certainly supports it.
I agree that the ABC editor needs another design iteration to make it more
usable (it was always a design aim to allow you to ignore the syntax-directed
parts of the editor - a design aim that was met for inputting text, but less
for changing it). On the other hand, I have taught ABC to first-year students,
and I noticed no problems for them with dealing with the editor.
> nothing works anything like the usual Mac user interface.
The problem here was: do we keep the interface the same across versions (so
that the Mac version works identically to the Unix version, a feature that some
people appreciate) or do we adhere fully to the platform standards? Again this
was partly a resource issue: we thought it more important to have a working Mac
version first.
> This approach was presumably dictated by the pedagogical aims of ABC
First and foremost a lack of resources, in a research institute with no
students, and few programmers.
> I can't see anybody using Mac ABC for any program longer than a page or that
> they were going to keep for more than a week.
Funnily enough, an empirical study of ABC (amongst programmers who could choose
which editor they used) showed that nearly all 'programs' in ABC (i.e how-to's,
since there is no concept of program per se in ABC) were less than a page long,
the average was around 3 lines if I remember right, and only one programmer
wrote how-to's longer than a page. The language itself encourages short
programs.
Steven Pemberton, CWI, Amsterdam; Steven.Pemberton@cwi.nl