On Sun, Apr 7, 2024 at 7:10 PM Dave Horsfall <dave@horsfall.org> wrote:

> On Tue, 2 Apr 2024, Charles H Sauer (he/him) wrote:
>
> [...]
>
> > I wrote a Fortran to PL/I crude translator in SNOBOL [...]
>
> Gadzooks...  For our "write a simple compiler" assignment I threatened to
> use SNOBOL, but my lecturer (Ken Robinson) threatened to fail me :-)
>
> Translating Fortran to PL/I is pretty straightforward.  It translates
pretty much 1-for-1 except for handling character data.  One could replace
Fortran's Hollerith-encoded character strings with an integer array on
which a PL/I character string has been overlay defined.  Back in 1977 I
translated the TOPS-10 version of the Adventure game, which was in Fortran,
into PL/I so that I could run it on our batch S/370 mainframe.  I used an
IBM 3277 transaction terminal as the interactive interface.  I very
carefully translated the TOPS-10 Fortran into IBM PL/I line by line, except
for the character data where I bit the bullet and used pure PL/I character
variables.  The whole thing ran the very first time and had only one
obscure bug:  instead of saying PLOVER ROOM as one did in the TOPS-10
version, you had to say PLOVERROOM.  Once that bug was fixed the PL/I
version worked like a charm until we got our VAX, where I did another port
of the TOPS-10 program so that it ran under VAX/VMS.  This time it stayed
in Fortran, but again there was funny business with character strings
because of the 36 vs. 32 bit word size.

If I were to write an automated, general Fortran-to-PL/I translator, SNOBOL
would be my language of choice.

-Paul W.

-Paul W.