units
Ken Dickey
kend at apple.com
Wed Nov 11 18:06:01 UTC 1998
>> OK, so when one of these funky non-mathematical objects gets passed to some
>> code that sends it the message #squared (intending on squaring), how do we
>> guess the right squared semantics, because you proposal will give the
>> wrong answer.
>
> Perhaps it's the wrong message at that point. In common practice natural
>language, one would need to delimit, e.g., "5 kilogram meters per second,
>squared". The delimiter is the comma before "squared". (In common practice
>technical notation, one would use parentheses and a superscript.) So
>perhaps sending >>, tells the Unit to "group" (the equivalent of the
>parentheses in technical notation). Then a succeeding >>squared squares
>the whole thing, as intended.
[I have not been following this, so take the following "cum grano salis"]
Numerical operations such should only operate on the numeric part of the
object.
I would punt on "squared" but use "kilogram meters per second second" in
the units part of the object. I.e. I suggest working out the
<value,unit> model/abstraction first and optimizing the unit syntax later.
$0.02
-KenD
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