TO_F90

A Fortran 90 program for converting fixed-format Fortran 77 code to
Fortran 90 free-format.   Other changes replace old Fortran constructs
with more modern ones.

The conversions made include:
1. Standard format (column 7-72) converted to free-format.
2. DO loops and IF blocks indented.
3. Most labels are removed from loops and replaced with END DO, CYCLE,
   EXIT, and DO-loop constructs where appropriate.
4. 3-way arithmetic IFs converted to IF .. THEN .. ELSE constructs.
5. TYPE and INTENT declarations inserted for all subroutine and
   function arguments.
6. Computed GOTOs converted to SELECT CASE constructs.
7. Embedded blanks are removed from numerical constants; they are illegal
   in free format.

N.B. Some known bugs are listed in the program comments.

N.B. Users may like to use a program such as TIDY, available from simtelnet,
before using TO_F90.   TIDY will convert Hollerith strings; TO_F90 will not.

Warning: Both TIDY and TO_F90 expect Fortran 77 code as input.
In particular, both programs are intolerant of so-called Fortran 77 code
containing DO .. END DO constructs and in-line comments after `!' (both
illegal in F77).

The program is supplied in source code form.   It is in standard Fortran 90.
It should compile with any full Fortran 90/95 compiler.


This is PUBLIC DOMAIN code; it may be freely distributed provided that
no unauthorized alterations are made.

Author  : Alan.Miller @ vic.cmis.csiro.au
Web site: http://www.ozemail.com.au/~milleraj



