(j3.2006) Interaction between F and P for output

Van Snyder Van.Snyder
Wed Nov 26 17:58:57 EST 2008

The list items in subclause 10.8.5 "P editing" of 08-007r2 that begin
"On output,..." are silent concerning the effect of P editing on F
editing for output.  The specification of the effect of P on F during
output is hiding in the first list item, which begins "On input,...."

With the little program

        program F_and_P
          print 1, 3742.0, 0.3742
        1 format ( f14.0, 4pf14.0 )
        end program F_and_P
five of my six compilers produce a program that (correctly) prints
         3742.         3742.
while one (incorrectly) prints
         3742.         0000.

This treatment of F and P interaction goes back to F66 (,, F77 (,, and f90/95 (10.6.5,

The effect of P on F output would be more clearly explained in a
separate list item, say between the second and third items.  I don't
think it's possible to rearrange the first list item both to be correct
and not to hide either the input or output effect.

Van Snyder                    |  What fraction of Americans believe 
Van.Snyder at jpl.nasa.gov       |  Wrestling is real and NASA is fake?
Any alleged opinions are my own and have not been approved or
disapproved by JPL, CalTech, NASA, the President, or anybody else.

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