From 0a8dc1d82b6344bbedfc34075b5dbdb8cce6de20 Mon Sep 17 00:00:00 2001
From: Joseph Ferano <joseph@ferano.io>
Date: Mon, 21 Sep 2026 07:34:43 +0700
Subject: [PATCH] sand.flan takes the def/defonce split

The colours were the report: edited, re-evaluated, unchanged, because
defvar had said init-once and meant it. They are a def now, and so is
gravity, which is a number to turn while the sand falls, and game-data,
which is a file to edit and see re-read.

The grid, the velocity field and the arena stay defonce: they are what
the running game is, and a re-run that emptied them would be a restart
wearing a re-run's name. current-color is the same argument about a
smaller thing -- a brush you picked is a brush you keep.
---
 sand.flan | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/sand.flan b/sand.flan
index 6afc3b6..3df4e51 100644
--- a/sand.flan
+++ b/sand.flan
@@ -12,8 +12,8 @@
 (defn dyn->f64 [v f64] f64 v)
 (defn dyn->u32 [v i64] u32 (u32 v))
 
-(defvar gravity dyn 0.05)
-(defvar colors dyn
+(def gravity dyn 0.05)
+(def colors dyn
   (let [v (vec-new dyn)]
     (push v 0xFFF00FFF)
     (push v 0x3B6E8CFF)
@@ -21,9 +21,9 @@
     (push v 0xCC6B1FFF)
     v))
 
-(defvar grid     [rows [cols u32]])
-(defvar velocity [rows [cols f32]])
-(defvar current-color dyn 0)
+(defonce grid     [rows [cols u32]])
+(defonce velocity [rows [cols f32]])
+(defonce current-color dyn 0)
 
 (defn clear-grid [] ()
   (set grid     (zeroed))
@@ -112,8 +112,8 @@
                              (rl/get-color c))))))
   (rl/draw-fps 20 20))
 
-(defvar frame Allocator (arena-new 262144))
-(defvar game-data dyn
+(defonce frame Allocator (arena-new 262144))
+(def game-data dyn
   (handler-case (edn/read-file "game-data.edn")
     [(FileError [c] nil)]))