June 2018 Update

Task/Fractran/Fortran/fractran-4.f

@@ -30,7 +30,7 @@
           N = IT	!A copy I can damage.
           NF = 0	!No factors found.
           P = 0		!Because no primes have been tried.
-       PP:DO WHILE (IT.GT.1)	!Step through the possibilities.
+       PP:DO WHILE (N.GT.1)	!Step through the possibilities.
        	    P = P + 1		!Another prime impends.
             F = PRIME(P)	!Grab a possible factor.
             POW = 0		!It has no power yet.
@@ -48,11 +48,10 @@
                 STOP "Not enough storage!"	!Quite.
               END IF			!But normally,
               NF = NF + 1		!Admit another factor.
-              FACTOR.PNUM(NF) = P	!Identify the prime.
+              FACTOR.PNUM(NF) = P	!Identify the prime. NOT the prime itself.
               FACTOR.PPOW(NF) = POW	!Place its power.
             END IF		!So much for that factor.
-            IF (N.LE.1) EXIT PP	!Perhaps nothing remains?
-          END DO PP	!Try another prime.
+          END DO PP	!Try another prime, if N > 1 still.
           FACTOR.PNUM(0) = NF	!Place the count.
         END FUNCTION FACTOR	!Thus, a list of primes and their powers.
 

Task/Fractran/Julia/fractran.julia

@@ -0,0 +1,32 @@
+function fractran(n::Integer, ratios::Vector{<:Rational}, steplim::Integer)
+    rst = zeros(BigInt, steplim)
+    for i in 1:steplim
+        rst[i] = n
+        if (pos = findfirst(x -> isinteger(n * x), ratios)) > 0
+            n *= ratios[pos]
+        else
+            break
+        end
+    end
+    return rst
+end
+
+using IterTools
+macro ratio_str(s)
+    a = split(s, r"[\s,/]+")
+    return collect(parse(BigInt, n) // parse(BigInt, d) for (n, d) in partition(a, 2))
+end
+
+fracs = ratio"""17 / 91, 78 / 85, 19 / 51, 23 / 38, 29 / 33, 77 / 29, 95 / 23,
+                77 / 19, 1 / 17, 11 / 13, 13 / 11, 15 / 14, 15 / 2, 55 / 1"""
+println("The first 20 in the series are ", fractran(2, fracs, 20))
+
+prmfound = 0
+n = big(2)
+while prmfound < 20
+    if isinteger(log2(n))
+        prmfound += 1
+        println("Prime $prmfound found: $n is 2 ^ $(Int(log2(n)))")
+    end
+    n = fractran(n, fracs, 2)[2]
+end

Task/Fractran/Perl-6/fractran-2.pl6

@@ -1,3 +1,6 @@
+sub fractran(@program) {
+    2, { first Int, map (* * $_).narrow, @program } ... 0
+}
 for fractran <17/91 78/85 19/51 23/38 29/33 77/29 95/23 77/19 1/17 11/13 13/11
         15/14 15/2 55/1> {
         say $++, "\t", .msb, "\t", $_ if 1 +< .msb == $_;

Task/Fractran/Ruby/fractran.rb

@@ -1,5 +1,5 @@
-str = %w[17/91 78/85 19/51 23/38 29/33 77/29 95/23 77/19 1/17 11/13 13/11 15/14 15/2 55/1]
-FractalProgram = str.map(&:to_r)                                #=> array of rationals
+ar = %w[17/91 78/85 19/51 23/38 29/33 77/29 95/23 77/19 1/17 11/13 13/11 15/14 15/2 55/1]
+FractalProgram = ar.map(&:to_r)                                #=> array of rationals
 
 Runner = Enumerator.new do |y|
   num = 2