[REBOL] Re: Using a Math oper. buried in a variable
From: henrikmk:gma:il at: 3-Apr-2009 15:49
On Fri, Apr 3, 2009 at 2:58 PM, Wall, Scott <Scott.Wall-xwave.com> wrote:
> Gregg wrote:
>> As with most things in REBOL, there are a number of ways to do what
>> you want. Here's another one:
> ...
>>>> op: :*
>
> I'm now trying to use this form in my program. But I'm having trouble
> when it comes to dividing. Here is what I tried doing and how it failed:
>
>>> op: :/
> ** Syntax Error: Invalid word-get -- :
> ** Near: (line 1) op: :/
>
> Any ideas on how to get this to work?
It will not work, since / can't be directly converted to a word and
used as a get-word. The trick would be to write it first as a string
and convert it:
get to-get-word "/"
That is not very pretty, is it? (But keep it in mind, when you need to
convert something unwieldy to a word. :-))
So we can do something else:
+ - * and / are normally infix operators (2 + 3). In REBOL 2 you can
use them as prefix operators (+ 2 3), which would work in the
examples, but you can't do this in REBOL 3. Instead, use the named
functions ADD, SUBTRACT, MULTIPLY and DIVIDE, so:
op: :divide
should work for you.
--
Regards,
Henrik Mikael Kristensen
