Re: [PATCH] scripts: improve checkstack

[Stephen Hemminger <shemminger@vyatta.com>]

On Sat, 20 Feb 2010 15:35:06 +0800
Cong Wang <amwang@redhat.com> wrote:

> Stephen Hemminger wrote:
> > Turn on strict checking, and get rid of annoying use of prototype.
> > Fix syntax error in declaration
> > 
> > Use efficient sort algorithm by using schwartzian transform.
> >   http://en.wikipedia.org/wiki/Schwartzian_transform
> 
> 
> Yeah, the idea is good, this can also make it more perlish. ;)
> 
> But...
> 
> 
> > -print sort bysize @stack;
> > +# Use Schwartzian transform to sort by last field (size)
> > +print map { $_->[0] }
> > +      sort { $b->[1] <=> $a->[1] }
> > +      map { [$_, /:\t*(\d+)$/] } @stack;
> 
> This regex here is not strictly the same as before.
> 
> Can we just keep the original regex? If not, what's wrong?

The original one had extra cruft:
  1. The expression is anchored on right, so leading .* is meaningless
  2. Putting tab directly makes it invisible when reading source (use \t)
  3. Want to match on number, not just anything (that is why the \d)