Many years ago, I wrote a program to draw a map of the world in any
one of several different projections.

This was back when computer time cost money, so I did not want to
contend with the overhead of a subroutine call in an inner loop.

The program, therefore, uses the assigned GO TO instead.

If you want a glance at what FORTRAN looked like in the bad old days,

http://www.quadibloc.com/comp/fort03.htm

John Savard

Quadibloc wrote:

I believe that was the original purpose of assigned GO TO,
as it existed even before SUBROUTINE and CALL.
Also, possibly the reason for extended range of DO.

-- glen

Quadibloc wrote:

I successfully forgot about goto a least 30 years ago.

Sjouke Burry wrote:

Presumably not in Fortran, then. That would have had to be F66 or
earlier. (F77 wasn't actually published until April of 1978, and it was
a while after that before compilers were out. That could count as almost
30 years, but not "at least" 30 years.) I'd have thought it pretty
awkward to program in F66 without the use of even a single goto;
possible, but darned awkward. I suppose you might have been using a
Fortran variant like Ratfor.

Richard Maine wrote:

F2/asm pdp 7
F66/asm pdp2/pdp11/microvax
F?? ibm186/286
f77 468/p??
C 468 and higher after that.
Basic/fortran/lisp at Arc risc pc(arc 310)
And I kind of disliked goto on all of them. ...

Sjouke Burry wrote:

You may not enjoy this article, then: D.E. Knuth, "Structured
Programming with the GOTO Statement," Computing Surveys, vol. 6, 1974.

--mecej4

On Aug 13, 11:04 am, mecej4 operamail.com> wrote:

Terence cantv.net> wrote:

The Elxsi compiler in the mid 80's actually implemented the comefrom
statement (and several variants) as a continuation of this spoof. It
wasn't documented, but I found out about it when Ralph Merkle (one of
the developers) suggested that I might be amused by looking at a certain
area in the compiler executable file. When I did so, I found a list of
strings containing mostly familliar Fortran keywords. Amidst those, I
spotted comefrom. A quick check verified that the statement actually
compiled and worked as "expected".

I later heard that the statement was pulled from the compiler after a
customer submitted a bug report (I think it was a
performance/optimization issue) related to the comefrom statement
implementation. The joke wasn't worth actually investing scarce support
resources on.

Terence wrote:

(snip)

The problem with COMEFROM is that it isn't so obvious if the
COME FROM is before or after the referenced statement is executed.
At least it seems less obvious than GO TO.

It seems a little convenient to COME FROM before the specified
statement is executed, in which case you can do something like:

COME FROM 123
WRITE(*,*) X,Y,Z
GOTO 123

at some convenient place, such as the end of the program, for
debugging purposes. The OS/360 Fortran G compiler has a debugging
system that works in a similar way with the AT statement.

-- glen

On Aug 12, 3:18 pm, Quadibloc wrote:

Attempting to compile that source using gfortran 4.3.0, using an
extension of
".f" and no -std overrides, produced the following.