blog: Improve code for Dragon curve

Author: ingydotnet

blog/2025-07-18.md

@@ -113,21 +113,20 @@ defn main(steps=511):
       nx ny =: +
         [(x + condp(== dir 0 1 2 -1 0))
          (y + condp(== dir 1 1 3 -1 0))]
-      ob ib =: nth([[8 4][2 1][4 8][1 2]] dir)
+      ob ib =: dir.nth([[8 4][2 1][4 8][1 2]])
       data =: update-in(data [y x] safe-bit-or ob)
              .update-in([ny nx] safe-bit-or ib)
       bbox =: +
         [min(minx nx) max(maxx nx)
          min(miny ny) max(maxy ny)]
       if i < steps:
-        recur: i.++ [nx ny] data bbox
+        recur: i.++, [nx ny], data, bbox
         vector: data bbox
 
-  doseq y (range miny maxy.++):
-    chars =:
-      for x (range minx maxx.++):
-        nth(" ╵╷│╴┘┐┤╶└┌├─┴┬┼" get-in(data [y x] 0))
-    say: str(chars*)
+  each y (miny .. maxy):
+    say: !:join
+      each x (minx .. maxx):
+        get-in(data [y x] 0).nth(" ╵╷│╴┘┐┤╶└┌├─┴┬┼")
 
 defn i-to-dir(n):
   n.bit-xor(bit-shift-right(n 1)):Long/bitCount % 4