Xref: utzoo comp.lang.c++:3928 comp.lang.eiffel:297
Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!ames!ucsd!hub!eiffel!bertrand
From: bertrand@eiffel.UUCP (Bertrand Meyer)
Newsgroups: comp.lang.c++,comp.lang.eiffel
Subject: Re: Eiffel vs. C++
Message-ID: <168@eiffel.UUCP>
Date: 6 Jul 89 23:45:08 GMT
References: <2689@ssc-vax.UUCP> <6590138@hplsla.HP.COM> <149@eiffel.UUCP> <1559@cbnewsc.ATT.COM>
Organization: Interactive Software Engineering, Santa Barbara CA
Lines: 40

From <1559@cbnewsc.ATT.COM> by nevin1@cbnewsc.ATT.COM (nevin.j.liber):

[Quoting from my previous message: ]

> |    Some care should be exercised, however, when one deals with programmers'
> |current habits. For example, a new language should not use an existing
> |notation in a way that confusingly departs from its accepted semantics.
> |(The Eiffel assignment operator, :=, is a case in point;
> |its semantics would probably have been different were it not for the fear
> |of confusing Algol-Pascal-Ada programmers.)


> [...] Assuming that you wanted to give the Eiffel
> assignment operator different semantics than those given by
> Algol/Pascal/Ada to ":=", why didn't you just pick another symbol (eg:
> ".=")?  Please elaborate.



[Perhaps :-) would do for assignment?] :-)

	Actually the Eiffel convention is the same as the Pascal and Ada
ones for entities of pointer/access/reference types, which is the reason
for keeping the same notation.

	In general it seems proper to avoid inventing a new notation
where there is no real semantic innovation and a widely accepted notation
exists, unless there are strong arguments against that notation. (An
example of the latter would be the Fortran/C use of = for assignment,
which conflicts with time-honored mathematical conventions.)
The language should look familiar in places where the concepts are indeed
familiar. There are a number of novel ideas in Eiffel, but assignment
is a quite standard concept. As one may expect, the properties of
assignment in Eiffel are not identical to those of its counterparts in
previous languages, but the differences do not seem big enough to warrant
a totally new notation. Call it lack of courage if you will.


-- Bertrand Meyer
bertrand@eiffel.com