OpenEuphoria

Re: foreach routine

• Posted by Chris Bensler <bensler at nt.net> Dec 22, 2006
• 647 views

duke normandin wrote:
> 
> c.k.lester wrote:
> > 
> > FMI, what is the benefit of a foreach statement vs. for x = y to z?

I've considered foreach in the past for various language designs and
preprocessor features. I could see no real gain and it creates issues when one
also wants access to the iterator in a foreach loop, which is often enough that a
foreach construct is too specific to be a good addition to Euphoria.


> > Would there be a performance benefit on the backend?

Not likely, possibly a very tiny one.


> Hi...
> 
> I'm too new to euphoria code to venture even a guess, never mind an opinion.
> Coming from Perl, I'm trying to emulate the following:
> 
> read(STDIN, $buffer, $ENV{CONTENT_LENGTH});
> @pairs = split(/&/, $buffer);
> foreach $pair (@pairs){
>     ($name, $value) = split(/=/, $pair);
>      blah
>      blah
> }
> 
> I'm going to use a `for' loop to `getc' CONTENT_LENGTH amount of chars and
> shove them into `sequence buffer'.
> 
> I've got a split routine that I think will work.
> 
> I just need to walk through the 'sequence pairs' one at a time, split
> again and stash each in there own sequence.
> 
> Like I said in a prior post -- sequences are so HUGE of a deal in Euphoria
> that the support for them ought to be a non-issue. As it stands now, the hoops
> that I *think* I'll have to jump through to do anything with sequences are
> bizarre. Maybe this is *one* of the issues that needs to be fixed in order
> to make a powerful language that much more attractive and efficient to use.
> 
> BTW... TP80-cgilib.e ! Still available?? Later....
> --
> duke

Here is some Eu code to do what you want (split() function sold separately)
Warning: code is not tested, consider it a guideline only

include get.e -- needed for get_bytes() and value()
sequence pairs,pair
sequence name,data -- ('value' is a standard routine name, so I will use 'data'
instead)
sequence buffer
object tmp -- temporary/intermediate variable

tmp = getenv("CONTENT_LENGTH")
if atom(tmp) then
  -- CONTENT_LENGTH was not found
else
  tmp = value(tmp)
  if tmp[1] != GET_SUCCESS then
    -- value() failed
  else
    buffer = get_bytes(STDIN,tmp[2])
    pairs = split(buffer,'&')
    for i = 1 to length(pairs) do
      pair = pairs[i]
      tmp = split(pair,'=')
      name = tmp[1]
      data = tmp[2]
      -- blah
      -- blah
    end for
  end if
end if

Chris Bensler
~ The difference between ordinary and extraordinary is that little extra ~
http://empire.iwireweb.com - Empire for Euphoria