Re: Re: Varför kan jag inte inte anropa A -- B -- C ?

[Robert Virding]

----- Original Message ----- 
From: "Sven-Olof Nystr|m" <svenolof@REDACTED>
To: "Robert Virding" <robert.virding@REDACTED>
Cc: "Pierpaolo BERNARDI" <bernardp@REDACTED>;
<erlang-questions@REDACTED>
Sent: Friday, October 17, 2003 9:51 AM
Subject: Re: Re: Varför kan jag inte inte anropa A -- B -- C ?


> Robert Virding writes:
>  > Unfortunately you are all missing something, -- is a big joke. After
>  > I had added the ++ syntax, it is just syntactic sugar really, I just
had
>  > to add -- as a joke. I was also planning to add ** and // but I
>  > couldn't really come up with good list meanings so I dropped it.
>  > That is why there is no really thought out semantics for --.
>  >
>  > The operator associativity had to be the same as ++ though. Sometimes
>  > I still get the feeling we should have done the same as Smalltalk.
>  >
>
> Of course, this means that the minusminus operator is now part of the
> language and must be supported in the future.

Yes, I know. Wonderful isn't it?

> It is also difficult to understand your motivation for making the ++
> operator right-associative. What prevents a compiler from implementing
> (X ++ Y) ++ Z as "first concatenate Y and Z, then concatenate X with
> the result"?

Just to make the associativity relate to how you would like it to work.
If the terms are expressions it makes it a little clearer what is happening.
At least I think so.

Robert