[REBOL] Re: Summing a list
From: izkata:gm:ail at: 2-Sep-2010 11:23
'if doesn't have an else-block by default. You can use "help if" to see its
refinements.
Two ways to do it, one with the refinement, the other with a different
function:
if/else empty? series [0] [add first series suma next series]
either empty? series [0] [add first series suma next series]
What Sunanda is doing is, exiting the function early if the series is
empty. That way the remainder only gets evaluated if the series is not
empty, acting like an 'else' without actually being one.
On Thu, Sep 2, 2010 at 11:06 AM, Emeka <emekamicro-gmail.com> wrote:
> Sunanda,
>
> I thought that "if" signature is this:
>
> if good-enough? nums [ bla blal] [weep weep]
>
> Why is it that yours is different?
> Emeka
>
> On Thu, Sep 2, 2010 at 4:57 PM, Sunanda <dhsunanda-gmail.com> wrote:
>
> >
> > Try this:
> >
> > suma: func [series] [
> > if empty? series [return 0]
> > add first series suma next series
> > ]
> >
> >
> > Your problem was having the [add first...] in a block. It needs to be
> > open code
> >
> > Sunanda
> > --
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