From c3a73e60bb19ea1d9ec2dc8f2506c86fdb2fdc26 Mon Sep 17 00:00:00 2001
From: razetime <raghuallthetime@hotmail.com>
Date: Fri, 18 Mar 2022 11:43:02 +0530
Subject: [PATCH] fractran

---
 fractran.bqn | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 fractran.bqn

diff --git a/fractran.bqn b/fractran.bqn
new file mode 100644
index 0000000..34033e7
--- /dev/null
+++ b/fractran.bqn
@@ -0,0 +1,35 @@
+# Fractran interpreter
+
+# Helpers
+_while_ ← {𝔽⍟𝔾∘𝔽_𝕣_𝔾∘𝔽⍟𝔾𝕩}
+ToInt ← 10⊸×⊸+˜´·⌽-⟜'0'
+ToFrac ← {
+  i ← ⊑/'/'=𝕩
+  ToInt¨i(↑⋈1⊸+⊸↓)𝕩
+}
+Split ← ((¬-˜⊢×·+`»⊸>)∘≠⊔⊢)
+
+Fractran ← {
+  𝕊 n‿num‿den:
+  ind ← ⊑/0=den|num×n
+  ⟨(n×ind⊑num)÷ind⊑den ⋄ num ⋄ den⟩
+}
+
+RunFractran ← {
+  steps 𝕊 inp‿prg:
+  num‿den ← <˘⍉>ToFrac¨' 'Split prg
+  step ← 1
+  list ← ⟨inp⟩
+  {
+    step +↩ 1
+    out ← Fractran 𝕩
+    list ∾↩ ⊑out
+    out
+  } _while_ {𝕊 n‿num‿den: (step<steps)∧ ∨´0=den|num} inp‿num‿den
+  list
+}
+
+seq ← 200 RunFractran 2‿"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"
+•Out "Generated numbers: "∾•Repr seq
+•Out "Primes: "∾•Repr (⌈=⌊)∘(2⊸(⋆⁼))⊸/ seq
+