OpenEuphoria

Re: Your thoughts on two item id methods?

• Posted by Bernie Ryan <xotron at bluefrog.com> Oct 18, 2005
• 447 views

Al Getz wrote:
> 
> Hello there,
> 
> 
> Im looking at something that needs to tell the difference between two
> different classes of elements in a loop.  The two methods presented
> here both work, but they work somewhat different.  I'd like to hear
> any thoughts anyone has on these two methods, as to which one if any
> seems better and why...
> 
> METHOD #1
> 
> Atoms are of one class, while sequences are of the other class.
> Here, we know items of class 1 are atoms, while class 2 items are sequences.
> This way we can tell the difference between class 1 items and class 2 items...
> 
> itemlist={ 1,2,3,{8,9},4,{6,7} } --atoms and sequences
> for k=1 to length(itemlist) do
>   item=itemlist[k]--atom or seq
>   if atom(item) then
>     DoClass1Stuff(item)
>   else
>     DoClass2Stuff(item)
>   end if
> end for
> 
> 
> METHOD #2
> 
> Atoms will be in a sequence where the first element is zero, while
> the other class will always have a '1' as first element with the real
> data in elements 2 and above.  Thus, class 1 elements start with a zero
> and class 2 elements start with a 1...
> 
> itemlist={ {0,1},{0,2},{0,3},{1,8,9},{0,4},{1,6,7} } --all sequences
> 
> for k=1 to length(itemlist) do
>   item=itemlist[k]--always a sequence
>   if item[1] then
>     DoClass2Stuff(item)
>   else
>     DoClass1Stuff(item)
>   end if
> end for
> 
> I'm not that worried about the increase in memory space taken by
> the second method.
> In each itemlist there will be approx the same number of class 1 items
> as there are class 2 items.
> 

Al:
  Why can't you doing this:

itemlist={ 1,2,3,{8,9},4,{6,7} } --atoms and sequences

for k=1 to length(itemlist) do
  if atom(itemlist[k]) then
    DoClass1Stuff(itemlist[k])
  else
    DoClass2Stuff(itemlist[k])
  end if
end for
 

Bernie

My files in archive:
w32engin.ew mixedlib.e eu_engin.e win32eru.exw

Can be downloaded here:
http://www.rapideuphoria.com/cgi-bin/asearch.exu?dos=on&win=on&lnx=on&gen=on&keywords=bernie+ryan