From fec30be7ddfbe0285a6b3e676ccc474db0c65abf Mon Sep 17 00:00:00 2001
From: Jeremy Penner <jeremy@sporktania.com>
Date: Tue, 30 Mar 2021 19:24:52 -0400
Subject: [PATCH] fix broken hot reload pattern, handle exceptions in game
 updates

---
 editor/imstate.fnl          |  2 ++
 editor/repl.fnl             | 27 ++++++++++++++++++++-------
 editor/replview.fnl         |  2 +-
 game/entities/bomb.fnl      |  9 +++++----
 game/entities/bomberman.fnl |  6 +++---
 game/mode.fnl               | 24 ++++++++++++++++++++++--
 game/tiles.fnl              |  6 +++---
 lib/util.fnl                | 12 +++++++++++-
 todo.txt                    |  5 -----
 9 files changed, 67 insertions(+), 26 deletions(-)

diff --git a/editor/imstate.fnl b/editor/imstate.fnl
index 2c15b9f..be539d5 100644
--- a/editor/imstate.fnl
+++ b/editor/imstate.fnl
@@ -160,6 +160,8 @@
   ; handle key events
   (when (focus view tag x y w h {:i 1 :iAnchor 1 :blink (love.timer.getTime)})
     (local f view.imstate.focus)
+    (when (> f.i (+ (length text) 1))       (set f.i (+ (length text) 1)))
+    (when (> f.iAnchor (+ (length text) 1)) (set f.iAnchor (+ (length text) 1)))
     (when view.imstate.text
       (set textNew (replace-selection view textNew view.imstate.text)))
     (each [_ key (ipairs (or view.imstate.keys []))]
diff --git a/editor/repl.fnl b/editor/repl.fnl
index 5dd9203..bc97046 100644
--- a/editor/repl.fnl
+++ b/editor/repl.fnl
@@ -3,11 +3,24 @@
 (local style (require :core.style))
 (local lume (require :lib.lume))
 
-(local repl {})
+(local repl (util.hot-table ...))
 
+(fn repl.text-height [text ?font]
+  (let [font (or ?font style.font)
+        (_ newlines) (text:gsub "\n" "\n")]
+    (* (font:get_height) (+ newlines 1))))
+
+(fn repl.inspect-table [tbl view x y-start w]
+  (var y y-start)
+  (var h 0)
+  (each [k v (pairs tbl)]
+    (let [kstr (fv k)
+          wk 1]
+          nil))
+  )
 (fn repl.inspect [v view x y w]
   (renderer.draw_text style.font (fv v) x y style.text)
-  (style.font:get_height))
+  (repl.text-height (fv v)))
 
 (fn repl.inspector [{: vals} view x y]
   (var h 0)
@@ -20,7 +33,7 @@
     (listener:append line)))
 
 (fn repl.run [{: listeners}]
-  (local inspector (util.fn repl :inspector))
+  (local inspector #(repl.inspector $...))
   (fennel.repl {:readChunk coroutine.yield
                 :onValues #(repl.notify listeners {:draw inspector :vals $1})
                 :onError (fn [errType err luaSource] (repl.notify listeners {:draw inspector :vals [err]}))
@@ -39,11 +52,11 @@
 (fn repl.new []
   (local result
     {:listeners []
-     :listen (util.fn repl :listen)
-     :unlisten (util.fn repl :unlisten)
-     :submit (util.fn repl :submit)
+     :listen #(repl.listen $...)
+     :unlisten #(repl.unlisten $...)
+     :submit #(repl.submit $...)
      :coro (coroutine.create repl.run)})
   (coroutine.resume result.coro result)
   result)
 
-repl
+repl.hot
diff --git a/editor/replview.fnl b/editor/replview.fnl
index 5aff52f..81cf65f 100644
--- a/editor/replview.fnl
+++ b/editor/replview.fnl
@@ -33,7 +33,7 @@
   (local cmd (or ?cmd self.cmd))
   (when (= ?cmd nil)
     (set self.cmd ""))
-  (self:append {:draw (util.fn ReplView :draw-cmd) : cmd})
+  (self:append {:draw #(self.draw-cmd $...) : cmd})
   (self.conn:submit cmd))
 
 (fn ReplView.draw [self]
diff --git a/game/entities/bomb.fnl b/game/entities/bomb.fnl
index 8961c92..9bdaec0 100644
--- a/game/entities/bomb.fnl
+++ b/game/entities/bomb.fnl
@@ -1,7 +1,8 @@
 (local util (require :lib.util))
 (local dim (require :game.dim))
 
-(local Bomb {})
+(local Bomb (util.hot-table ...))
+
 (fn draw-ticking [bomb x y]
   (love.graphics.setColor 0.4 0.4 0.4)
   (love.graphics.circle :fill x y (/ dim.tilesize 2))
@@ -39,9 +40,9 @@
       :exploding (rules.clear-bomb bomb))))
 
 (fn Bomb.new []
-  {:state :ticking :timer 3 :solid true :draw (util.fn Bomb :draw) :update (util.fn Bomb :update)})
+  {:state :ticking :timer 3 :solid true :draw #(Bomb.draw $...) :update #(Bomb.update $...)})
 
 (fn Bomb.new-explosion []
-  {:state :exploding :timer 0.5 :deadly true :draw (util.fn Bomb :draw) :update (util.fn Bomb :update)})
+  {:state :exploding :timer 0.5 :deadly true :draw #(Bomb.draw $...) :update #(Bomb.update $...)})
 
-Bomb
+Bomb.hot
diff --git a/game/entities/bomberman.fnl b/game/entities/bomberman.fnl
index 52b8f58..b0ca496 100644
--- a/game/entities/bomberman.fnl
+++ b/game/entities/bomberman.fnl
@@ -4,7 +4,7 @@
 (local {: edge : vec*} (util.require :game.helpers))
 (local map (require :game.tilemap))
 
-(local bomberman {})
+(local bomberman (util.hot-table ...))
 (set bomberman.keymap {:up :w :down :s :left :a :right :d :bomb :x})
 
 (fn bomberman.draw [entity]
@@ -30,6 +30,6 @@
     (rules.place-bomb (map.world-to-tile entity.pos))))
 
 (fn bomberman.new [pos]
-  {: pos :vel [0 0] :draw (util.fn bomberman :draw) :update (util.fn bomberman :update)})
+  {: pos :vel [0 0] :draw #(bomberman.draw $...) :update #(bomberman.update $...)})
 
-bomberman
+bomberman.hot
diff --git a/game/mode.fnl b/game/mode.fnl
index cbd76b2..3987409 100644
--- a/game/mode.fnl
+++ b/game/mode.fnl
@@ -2,15 +2,35 @@
 (local map (require :game.tilemap))
 (local rules (require :game.rules))
 
-(fn update [dt]
+(fn game-update [dt]
   (map.update-entitymap state.bombs dt rules)
   (each [_ entity (ipairs state.entities)]
     (entity:update dt rules)))
 
-(fn draw []
+(fn exception-update [dt]
+  (when (love.keyboard.isDown :f2)
+    (set state.update-exception nil)))
+
+(fn update [dt]
+  (if state.update-exception
+    (exception-update dt)
+    (xpcall #(game-update dt) (fn [msg]
+      (set state.update-exception (.. msg "\n" (debug.traceback)))))))
+
+(fn game-draw []
   (map.draw-tilemaps 0 0 [state.bombs state.map])
   (each [_ entity (ipairs state.entities)]
     (entity:draw)))
 
+(fn exception-draw []
+  (love.graphics.setColor 1 0 0 1)
+  (love.graphics.setNewFont 14)
+  (love.graphics.printf (.. "Press F2 when resolved\n" state.update-exception) 20 20 (- (love.graphics.getWidth) 40)))
+
+(fn draw []
+  (if state.update-exception
+    (exception-draw)
+    (game-draw)))
+
 {: update : draw}
 
diff --git a/game/tiles.fnl b/game/tiles.fnl
index a4e5a5b..3893ddc 100644
--- a/game/tiles.fnl
+++ b/game/tiles.fnl
@@ -1,7 +1,7 @@
 (local dim (require :game.dim))
 (local util (require :lib.util))
 
-(local tileset {})
+(local tileset (util.hot-table ...))
 (fn rect [x y color]
   (love.graphics.setColor (table.unpack color))
   (love.graphics.rectangle :fill
@@ -35,7 +35,7 @@
     :breakable true}
    {:name :dot
     :edible true}
-  ] (util.fn tileset :bombertile-draw)))
+  ] #(tileset.bombertile-draw $...)))
 
-tileset
+tileset.hot
 
diff --git a/lib/util.fnl b/lib/util.fnl
index 2676d3e..4750016 100644
--- a/lib/util.fnl
+++ b/lib/util.fnl
@@ -53,6 +53,16 @@
 (fn swappable-require [modname]
   (swappable (require modname)))
 
+(fn hot-table [modname]
+  (local tbl {})
+  (fn find-table []
+    (let [loaded-pkg (. package.loaded modname)]
+      (if (= (type loaded-pkg) :table) loaded-pkg) tbl))
+  (setmetatable {:hot tbl} {
+    :__index (fn [_ key] (. (find-table) key))
+    :__newindex (fn [_ key val] (tset (find-table) key val))
+  }))
+
 (fn readjson [filename]
   (local f (io.open filename :r))
   (local text (f:read "*a"))
@@ -91,6 +101,6 @@
 
 {: int8-to-bytes : int16-to-bytes : int24-to-bytes : bytes-to-uint8 : bytes-to-uint16 : bytes-to-uint24
  : splice : lo : hi
- : reload : hotswap : swappable :require swappable-require :fn mk-swappable-fn
+ : reload : hotswap : swappable :require swappable-require : hot-table
  : readjson : writejson : waitfor : in-coro : multival}
 
diff --git a/todo.txt b/todo.txt
index b777f82..3d4fd56 100644
--- a/todo.txt
+++ b/todo.txt
@@ -1,11 +1,6 @@
 TODO:
-* all usages of util.fn are wrong!! you can't use the table as locally defined as it will disappear!!! aargh
 * tile editor (geometric shapes for now?)
 
-DEBUG TOOLS:
-#1 problem: update failing crashes the editor
-- store exception and stop running game; patch and restart
-
 Repl-y thing:
 appends objects to a list (inspectable?)