HP 3000 Manuals

HP FORTRAN 77/iX Reference

MIXED_FORMATS Directive 

The MIXED_FORMATS directive allows you to cause a numeric format
descriptor of a type different from the numeric list item to override the
data type of the list item.

Syntax 

$MIXED_FORMATS [ON ]
               [OFF]

Default               Off.

Location              The MIXED_FORMATS directive can appear anywhere in
                      your program.

Toggling/ Duration    Remains in effect until another occurrence of the
                      MIXED_FORMATS directive changes it.

Additional Information 


NOTE  The MIXED_FORMATS directive is not recommended for general use.  It
      is an extension to the ANSI 77 standard, and programs using it are
      not portable to systems without mixed formatting capability.  If
      list items and actual data types do not match, a floating-point
      exception could occur.


When MIXED_FORMATS is on, the type of the numeric format descriptor in
input or output overrides the type of the list item.  However, no type
conversion is done on the list item.  The example below illustrates the
effect of the MIXED_FORMATS directive.

Example 

           PROGRAM mixfmts
     $MIXED_FORMATS ON
           INTEGER*4 i4
           REAL*4 r4
           CHARACTER*12 std, mixed
           EQUIVALENCE (i4,r4)

     C Integer type coercion
           i4 = -12
       100 FORMAT (I12)
           WRITE (mixed,100) r4
           WRITE (std,100) i4
           IF (mixed .NE. std) STOP 'Failed 1'

     C Real type coercion
           r4 = 123.456
       101 FORMAT (E12.3)
           WRITE (std,101) r4
           WRITE (mixed,101) i4
           IF (mixed .NE. std) STOP 'Failed 2'
           STOP 'Passed.'
           END

MPE/iX 5.0 Documentation