I’ve talked about the toy programming problem fizzbuzz on this blog a few times. In R, you might do something like this:

for (i in 1:100){
if (i%%3==0) # divisible by 3
if (i%%5==0)
print("fizzbuzz")
else
print("fizz")
else if (i%%5==0)
print("buzz")
else
print(i)
}


Or to be a bit more R-ish, you might do something like:

f <- function(i){
if (i%%3==0)
if (i%%5==0)
return("fizzbuzz")
else
return("fizz")
else if (i%%5==0)
return("buzz")
else
return(i)
}

sapply(1:100, f)


But there’s a problem. That’s all too readable! When I look at it, I know exactly what it’s doing.

Enter Fortran.

I spend most of my life programming in Fortran these days — which I then hook into R via C wrappers in a cumbersome process that I don’t wish on my enemies. Anyway, the point is Fortran is really nice for matrix operations, and a hideous monstrosity for most everything else. Especially old Fortran, like Fortran 77. It tends to be full of GOTO statements that make reading the program an impossibility.

So that’s precisely why I developed a fizzbuzz in Fortran, using nothing but GOTO’s, IF’s, FORMAT, and WRITE statements:

* THIS PROGRAM IS COPYWRITE ME ALL YEARS DON NOT COPOY!!!!
PROGRAM GOTOHEL
I
$N$    T
$E$    G
$E$R A
$,B PARAMETE$ R     (
$A =$ 3,B=5 ,
$M=10$0)
3290 FORMAT(A,F5.3)
GOTO 1209
7365 CONTINUE
WRITE (*,3290) " "
GOTO 7356
1121 FORMAT(I4,F8.3)
3298 CONTINUE
IF(MOD(I,A)
$.EQ.Z) THEN GOTO 2359 ELSE IF(MOD(I,B)$.EQ.Z) THEN
GOTO 8125
ELSE
WRITE (*,2930) I
GOTO 7365
END IF
7235 FORMAT(A,F5.3)
7356 CONTINUE
I=I
$+1 GOTO 1249 2930 FORMAT(I4,$)
2359 CONTINUE
WRITE (*,2390) "FIZZ"
IF (MOD(I,B)
$.EQ.Z) THEN GOTO 8125 END IF GOTO 7365 1249 CONTINUE IF(I.GT.M) THEN GOTO 3285 ELSE GOTO 3298 ENDIF 2390 FORMAT(A,$)
1209 CONTINUE
WRITE (*,2930) 1
I=I+1
GOTO 7365
8125 CONTINUE
WRITE (*,2390) "BUZZ"
GOTO 7365
3285 CONTINUE
END


This will compile with gfortran and gnu f77, so to all the enterprises out there still depending on Fortran 77, this code is just for you! Here’s an example proving that this does indeed work:

user@localhost$f77 fizzbuzz.f MAIN gotohel: user@localhost$ ./a.out
1
2
FIZZ
4
BUZZ
FIZZ
7
8
FIZZ
BUZZ
11
FIZZ
13
14
FIZZBUZZ
16
17
FIZZ
19
BUZZ
FIZZ
22
23
FIZZ
BUZZ
26
FIZZ
28
29
FIZZBUZZ
31
32
FIZZ
34
BUZZ
FIZZ
37
38
FIZZ
BUZZ
41
FIZZ
43
44
FIZZBUZZ
46
47
FIZZ
49
BUZZ
FIZZ
52
53
FIZZ
BUZZ
56
FIZZ
58
59
FIZZBUZZ
61
62
FIZZ
64
BUZZ
FIZZ
67
68
FIZZ
BUZZ
71
FIZZ
73
74
FIZZBUZZ
76
77
FIZZ
79
BUZZ
FIZZ
82
83
FIZZ
BUZZ
86
FIZZ
88
89
FIZZBUZZ
91
92
FIZZ
94
BUZZ
FIZZ
97
98
FIZZ
BUZZ