OpenEuphoria

Re: Homogeneous sequence

• Posted by Bob Elia <bobelia200 at netzero.n??> Aug 12, 2007
• 665 views

Bob Elia (me) wrote:
> 
> Juergen Luethje wrote:
> > 
> > Ricardo Forno wrote:
> > 
> > > Hi all.
> > > While reading this thread, I browsed my General Functions package and saw
> > > an obvious mistake in the example for the Structure function, which does
> > > a very similar thing to one of the functions discussed here.
> > > For now, I don't plan to post a correction, because the mistake is so
> > > obvious.
> > > Regards.
> > 
> > Hello Ricardo,
> > 
> > this reminds me ...
> > When looking for the solution of a general problem, I actually should
> > firstly look into your great General Functions package.
> > 
> > Regards,
> >    Juergen
> 
> Hi, Juergen
> 
> This works, I think, though I'd rather have an iterative solution.
> 
> }}}
<eucode>
> type seq_of_atom_or_empty(sequence s)
>     if equal(s, {}) then
>         return 1
>     end if
>     for i = 1 to length(s) do
>         if sequence(s[i]) then
>             return 0
>         end if
>     end for
>     return 1
> end type
> 
> function object_structure_2(object x)
>     if atom(x) then
>         return 1
>     elsif seq_of_atom_or_empty(x) then
>         return {}
>     end if
> 
>     for i = 1 to length(x) do
>         x[i] = object_structure_2(x[i])
>     end for
>     return x
> end function
> 
> global type homogeneous_sequence_2 (object x)
>    object struc
> 
>    if atom(x) then
>       return 0
>    end if
> 
>    if length(x) = 0 then
>       return 1                  -- ?
>    end if
> 
>    struc = object_structure_2(x[1])
>    for i = 2 to length(x) do
>       if not equal(struc, object_structure_2(x[i])) then
>          return 0
>       end if
>    end for
>    
>    return 1
> end type
> 
> 
> -- Demo:
> object a, b, c
> a = {3,{3 ,5,{5,2},4}}
> b = {4,{5 ,1,{9,2},4}}
> c = {4,{{},1,{9,2},4}}
> 
> -- ? object_structure(a)
> -- ? object_structure(b)
> -- ? object_structure(c)
> -- ? homogeneous_sequence({a,b})
> -- ? homogeneous_sequence({a,c})
> -- ? homogeneous_sequence({b,c})
> ? object_structure_2(a)
> ? object_structure_2(b)
> ? object_structure_2(c)
> ? homogeneous_sequence_2({a,b})
> ? homogeneous_sequence_2({a,c})
> ? homogeneous_sequence_2({b,c})
> 
> </eucode>
{{{

> 
> Bob

Nope, that doesn't work.  I was trying to account for strings of un-equal
length but {65,66,67} might not be one.  Oops.

In what form is the user providing this data? As Euphoria objects?
Or are you converting it?

Bob