[565] in Coldmud discussion meeting

Assignment Operator.

daemon@ATHENA.MIT.EDU (Tue Nov 8 18:49:55 1994 )

From: brandon@avon.declab.usu.edu
To: coldstuff@MIT.EDU
Date: Tue, 08 Nov 94 16:44:51 -0700


Ok, this is my argument for changing the assignment operator from '=' to ':='.
This argument is NOT for changing assignments to expressions (since some people
seem to confuse these two issues).  I don't want assignments as expressions.

The reasons I would like to change the assignment operator:

   * removes a touch of confusion in the language
   * it makes more sense logistically

The only valid reason I can think of for not changing it:

   * tradition, C has always been '='

- The reason it removes a touch of confusion from the language is because
currently all of the operators which include an equals sign also include
some other character to identify what specific operation should be occuring.
From a novice point of view it is extremely easy to confuse '=' and '=='.
If assignments were expressions this problem would be much more immense, as
the code would still compile but may have disastrous effects.  However, we
do not have assignments as expressions (nor is this an argument FOR
assignments as expressions), but it is still a matter of confusion.  As an
example, look at the following two blocks of code from the view of a novice
(do not try to read it logically, I'm just spamming):

while (x == y || y == z && z <= STOP)
    y = y + 1;
    for i in [1..listlen(list)] {
        x = i + y;
        if (x == y)
            list = setadd(list, part, list[i][x + z]);
    }
}

Versus:

while (x == y || y == z && z <= STOP)
    y := y + 1;
    for i in [1..listlen(list)] {
        x := i + y;
        if (x == y)
            list := setadd(list, part, list[i][x + z]);
    }
}

Now from my point of view, I will be explaining the language of ColdC to a
lot of people (it will just happen), and a majority of these people will
never have programmed before.  The above change--while small--would simply
lessen how much I would have to explain. From the experience I have had so
far in explaining MOO and C to other people, assignments as '=' is ALWAYS
a major hangup in learning the language.

- It makes more sense logistically because it is more like an actual english
statement.  Yes, this is not english, but aspects of it do model how we
think (otherwise we would not even use an equals sign at all).  I fleshed
out this aspect before but the best is in how one might right an example...

    Example: body of example.

- By tradition, C has always been '=', so why should we change it?  I
outlined why we should change it above.  The reason we should break tradition
is because ColdC is _NOT_ C, so we should not force our language to stick
with bad aspects of C, such as '=' being an assignment operator.  Otherwise
we may as well add in other aspects of C such as the for syntax, pointers,
etc.  I look at this change as one breaking tradition for the better.
The way I see it is if we bind how ColdC is structured to the styles of one
language we are horribly limiting the potential scope.

-Brandon Gillespie (Lynx)-

(BTW, as far as assignments as expressions, I would side with Greg.  In my
opinion the advantages of such an ability are only in giving the programmer
an ability to obfuscate their code even more.  I would prefer to keep the
language simple so as to be easy to learn for beginners.)