From: Ben Harris <bjh21@bjh21.me.uk>
Date: Sun, 12 May 2024 10:41:46 +0000 (+0100)
Subject: 12: Use the primitive •_while_: it's actually easier to understand
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~bjharris/git?a=commitdiff_plain;h=aaa4d1680709d6a5799049159d0ff6c8ba850463;p=aoc-2022.git

12: Use the primitive •_while_: it's actually easier to understand
---

diff --git a/12/12a.bqn b/12/12a.bqn
index 12a1975..f0ebe28 100644
--- a/12/12a.bqn
+++ b/12/12a.bqn
@@ -1,6 +1,3 @@
-# From https://mlochbaum.github.io/BQN/doc/control.html
-While   ← {𝕩•_while_𝕨@}´
-
 Prep←{
   start⇐'S'=𝕩
   end⇐'E'=𝕩
@@ -15,12 +12,8 @@ Main←{𝕊⟨start,end,map⟩:
   Flow←{
     𝕩∨(«𝕩∧can_go_n)∨(»𝕩∧can_go_s)∨(«˘𝕩∧can_go_w)∨(»˘𝕩∧can_go_e)
   }
-  now←start
   count←0
-  While {𝕤,¬∨´⥊(now∧end)}‿{𝕤
-    now↩Flow now
-    count+↩1
-  }
+  {count+↩1 ⋄ Flow 𝕩} •_while_ {¬∨´⥊(𝕩∧end)} start
   count
 }
 
diff --git a/12/12b.bqn b/12/12b.bqn
index 177d917..d92f7c9 100644
--- a/12/12b.bqn
+++ b/12/12b.bqn
@@ -1,6 +1,3 @@
-# From https://mlochbaum.github.io/BQN/doc/control.html
-While   ← {𝕩•_while_𝕨@}´
-
 Prep←{
   start⇐'S'=𝕩
   end⇐'E'=𝕩
@@ -16,12 +13,8 @@ Main←{𝕊⟨start,end,map⟩:
   Flow←{
     𝕩∨(«𝕩∧can_go_n)∨(»𝕩∧can_go_s)∨(«˘𝕩∧can_go_w)∨(»˘𝕩∧can_go_e)
   }
-  now←start
   count←0
-  While {𝕤,¬∨´⥊(now∧end)}‿{𝕤
-    now↩Flow now
-    count+↩1
-  }
+  {count+↩1 ⋄ Flow 𝕩} •_while_ {¬∨´⥊(𝕩∧end)} start
   count
 }