Re: Life without eval

2000-08-06 Thread dLux

/--- On Fri, Aug 04, 2000 at 05:58:44PM +0100, Piers Cawley wrote:
|  At 02:31 PM 8/4/00 +0200, dLux wrote:
| My suggestion is: declare "eval $scalar" as a bad guy.

|  It's not just string eval. It's also do FILE and require.

|  It's a  powerful construct, though,  and I wouldn't declare  it as
|  evil.
|  Possibly  as "unimplemented  on  some platforms  (read: palm)"  or
|  "The
|  optimizer  loathes eval/require/do  FILE after  BEGIN time  with a
|  passion you
|  couldn't imagine", but not evil.
|
| But, if the FILE it's being 'do'ne to is actually precompiled
| bytecode...
\---

I rethought  this thinggy, and (because  of the config files  or other
"do" and  "require") the compiler needs  to be available, but  I think
the  best place  is  in the  libperl.so (or  libperl.prc  in palm  for
example).  It  could make  a  compiled  file  if necessary  (and  have
access  to  the  file)  like  python does,  and  only  called  when  a
non-compiled code is referenced (like eval).

But   module  writers   should  minimize   the  usage   of  the   eval
construct...

dLux
--
== Whip me. Beat me. Make me maintain AIX ==



Re: Life without eval

2000-08-04 Thread Tom Christiansen

Hello!

  I am  thinking about the  perl compiler,  and I thought  if somebody
avoid  using  the  "eval  $scalar",  the  compiled  code  (perl  to  C
compiled code) may  not contain a full perl interpreter. If  it is the
case, we must  say to any module developer: Don't  use "eval $scalar"!
This syntax should remain for small dirty scripts.
  Most of the work should be done with "no strict" mode.

  My suggestion is: declare "eval $scalar" as a bad guy.

  Comments? (I may write an RFC if it worth...)

eval is very powerful.  Don't knock it.  Remember the beauty
of the read/eval/print loop from your first lisp class.

--tom



Re: Life without eval

2000-08-04 Thread Simon Cozens

On Fri, Aug 04, 2000 at 12:24:01PM -0400, Dan Sugalski wrote:
 At 02:31 PM 8/4/00 +0200, dLux wrote:
My suggestion is: declare "eval $scalar" as a bad guy.
 
 It's not just string eval. It's also do FILE and require.

Which you need at runtime, even in compiled code, to run external
configuration files written in Perl. Oops!

-- 
Going to church does not make a person religious, nor does going to school
make a person educated, any more than going to a garage makes a person a car.



Re: Life without eval

2000-08-04 Thread Dan Sugalski

At 01:30 AM 8/5/00 +0900, Simon Cozens wrote:
On Fri, Aug 04, 2000 at 12:24:01PM -0400, Dan Sugalski wrote:
  At 02:31 PM 8/4/00 +0200, dLux wrote:
 My suggestion is: declare "eval $scalar" as a bad guy.
 
  It's not just string eval. It's also do FILE and require.

Which you need at runtime, even in compiled code, to run external
configuration files written in Perl. Oops!

Yup, oops indeed. OTOH, if we do bytecompiled files (like emacs .el/elc 
stuff), it's not a huge oops, since we may well be able to load in the 
bytecompiled version. And it does mean that folks writing perl code to run 
on palms and other small devices might want a Plan B to save config files 
off. Which is just fine, TMTOWTDI.

Dan

--"it's like this"---
Dan Sugalski  even samurai
[EMAIL PROTECTED] have teddy bears and even
  teddy bears get drunk