Re: A couple of questions about goops method parameters

[Neil Jerram]

Taylan Ulrich Bayirli/Kammer <address@hidden> writes:

> Panicz Maciej Godek <address@hidden> writes:
>
>> [...] it's hard for me to see the advantage of FRP over OOP in
>> practical systems (e.g. windowed applications with buttons and so
>> on). [...]
>
> An off-topic remark:
>
> I don't know about *functional* reactive programming but from my
> experience so far as an iOS developer, I've been *longing* for a
> reactive programming system that automates state changes even if not
> fully hiding them.  It would be invaluable being able to say
> "button2.leftEdge = button1.rightEdge + 20px" and have this equation be
> held automatically on changes to the layout of button1 (which might
> happen because it itself reacts to other layout changes), or to be able
> to say "button.disabled = condition1 or condition2" and have the
> disabled status of button update automatically as the truthiness of the
> conditions changes.  (The former use-case is actually covered by "layout
> constraints", but that's strictly limited to layouting.)

IIRC, Metafont does that; but obviously it isn't intended as a general
language.  Are there more general languages that solve equations like
this?

Regards,
        Neil