Re: Automatic allocation of an available file unit

Joe Krahn <lastname_at_niehs.nih.gov@xxxxx> wrote:

I see that the plan is to use negative unit numbers for automatically
assigned units. It seems to me that there would be fewer conflicts by
using positive numbers starting at some number higher than the old
compiler limits, an therefore unlikely to conflict with old code using
constant unit numbers.

What number is this that is higher than "the old compiler limits"? I
thought I recalled that some compilers allowed any postive number. On
the other hand, negative unit numbers have previously been invalid. So I
fail to see how numbers that were formerly valid could have fewer
conflicts than ones that were formerly invalid. I must have missed
something about your point.

--
Richard Maine | Good judgement comes from experience;
email: last name at domain . net | experience comes from bad judgement.
domain: summertriangle | -- Mark Twain
.

Relevant Pages

  • Re: Automatic allocation of an available file unit
    ... It seems to me that there would be fewer conflicts by ... What number is this that is higher than "the old compiler limits"? ... negative unit numbers have previously been invalid. ... The only bad part of allowing negative unit numbers is for people who use variables to hold file unit numbers, where an invalid value means the file is not opened. ...
    (comp.lang.fortran)
  • Re: Automatic allocation of an available file unit
    ... It seems to me that there would be fewer conflicts by ... negative unit numbers have previously been invalid. ... The only bad part of allowing negative unit numbers is for people who use variables to hold file unit numbers, where an invalid value means the file is not opened. ... The file unit finding routine should determine if the unit is /valid/, not some magic number that changes from compiler to compiler. ...
    (comp.lang.fortran)
  • Re: Automatic allocation of an available file unit
    ... fail to see how numbers that were formerly valid could have fewer ... conflicts than ones that were formerly invalid. ... By old code assuming that negative numbers cannot refer to ...
    (comp.lang.fortran)