Data commit

Task/Fractran/Wren/fractran.wren

@@ -0,0 +1,31 @@
+import "/big" for BigInt, BigRat
+
+var isPowerOfTwo = Fn.new { |bi| bi & (bi - BigInt.one) == BigInt.zero }
+
+var fractran = Fn.new { |program, n, limit, primesOnly|
+    var fractions = program.split(" ").where { |s| s != "" }
+                                      .map { |s| BigRat.fromRationalString(s) }
+                                      .toList
+    var results = []
+    if (!primesOnly) results.add(n)
+    var nn = BigInt.new(n)
+    while (results.count < limit) {
+        var fracs = fractions.where { |f| (f * nn).isInteger }.toList
+        if (fracs.count == 0) break
+        var frac = fracs[0]
+        nn = nn * frac.num / frac.den
+        if (!primesOnly) {
+            results.add(nn.toSmall)
+        } else if (primesOnly && isPowerOfTwo.call(nn)) {
+            var prime = (nn.toNum.log / 2.log).floor
+            results.add(prime)
+        }
+    }
+    return results
+}
+
+var program = "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"
+System.print("First twenty numbers:")
+System.print(fractran.call(program, 2, 20, false))
+System.print("\nFirst ten primes:")
+System.print(fractran.call(program, 2, 10, true))