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Re: something like perl's 'require 5.4'
Paul van Delst wrote:
> JD Smith wrote:
> > Paul van Delst wrote:
> > >
> > > wot about
> > >
> > > IDL> print, double('5.4.1') ge 5.4d0
> > > 1
> > >
> > Because it's exactly the same! Yes it's ge, but is it gt?
> > IDL> print, double('5.4.1') gt 5.4d0
> > 0
> > IDL> print, double('5.4.1') eq 5.4d0
> > 1
> > No it's not, it's eq. Same problem. So use this if you don't care
> > about the last digit and don't want to be open about it (it's not
> > exactly obvious this is the case). Use the string compare method
> > otherwise.
> > > Doesn't assuage your other concerns regarding the significance of the last digit however.
> > > I use comparisons like the above for code that contains BREAK, CONTINUE, SWITCH, etc
> > > statements. Or similar for the version in which pointers and objects were introduced (5.2?
> > > can't remember).
> > The problem here is you'll not err cleanly... unknown control statements
> > will cause compile errors. Not a lot that we can do about this.
> Nuh-uh. They're interpreted as user functions/procedures.
Right. I stand corrected. Just hope they don't have any such named
routines lying about on their path. Dereferencing pointers will cause
compile error in old versions though, right?