From 856d6400f5d0802f4b75881e019be2de3cbecfc6 Mon Sep 17 00:00:00 2001
From: Jeremy Penner <jeremy@sporktania.com>
Date: Sun, 11 Apr 2021 14:08:57 -0400
Subject: [PATCH] Refactor inspector to use multimethods, generalize picking
 best one

---
 editor/repl.fnl    | 45 +++---------------------------
 inspector/init.fnl | 68 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+), 41 deletions(-)
 create mode 100644 inspector/init.fnl

diff --git a/editor/repl.fnl b/editor/repl.fnl
index 36eef94..90cd3f1 100644
--- a/editor/repl.fnl
+++ b/editor/repl.fnl
@@ -3,50 +3,13 @@
 (local style (require :core.style))
 (local lume (require :lib.lume))
 (local {: textbutton} (util.require :editor.imstate))
-
+(local {: inspect} (util.require :inspector))
 (local repl (util.hot-table ...))
 
-(fn repl.text-height [text ?font]
-  (let [font (or ?font style.code_font)
-        (_ newlines) (text:gsub "\n" "\n")]
-    (* (font:get_height) (+ newlines 1))))
-
-(fn get-state [tbl k depth state]
-  (when (= nil (. state k))
-    (tset state k {:collapsed (= (type (. tbl k)) :table) :children {}}))
-  (. state k))
-
-(fn repl.inspect-table [tbl view x y w depth state]
-  (local font style.code_font)
-  (var h 0)
-  (each [k v (pairs tbl)]
-    (let [kstate (get-state tbl k depth state)
-          kstr (fv k)
-          wk (font:get_width kstr)
-          xoffset (+ wk style.padding.x)
-          toggle-collapse (textbutton view kstr x (+ y h))
-          hv (if kstate.collapsed
-                (do (renderer.draw_text font "..." (+ x xoffset) (+ y h) style.syntax.comment) (font:get_height))
-                (repl.inspect v view (+ x xoffset) (+ y h) (- w xoffset) (+ depth 1) kstate.children))]
-      (when toggle-collapse (tset (. state k) :collapsed (not kstate.collapsed)))
-      (set h (+ h hv style.padding.y))))
-  h)
-
-(fn repl.inspect-default [v view x y w depth state]
-  (renderer.draw_text style.code_font (fv v) x y style.text)
-  (repl.text-height (fv v)))
-
-(fn repl.inspect [v view x y w depth state]
-  (if (> w 0)
-    (if (and (= (type v) :table) (not= (next v) nil))
-      (repl.inspect-table v view x y w depth state)
-      (repl.inspect-default v view x y w depth state))
-    0))
-
-(fn repl.inspector [{: vals : state} view x y]
+(fn repl.inspector [{: vals : states} view x y]
   (var h 0)
   (each [i v (ipairs vals)]
-    (set h (+ h (repl.inspect v view x (+ y h) view.size.x 1 state))))
+    (set h (+ h (inspect (. states i) v view x (+ y h) view.size.x))))
   (+ h style.padding.y))
 
 (fn repl.notify [listeners line]
@@ -55,7 +18,7 @@
 
 (fn repl.mk-result [vals]
   (local inspector #(repl.inspector $...))
-  {:draw inspector : vals :state {}})
+  {:draw inspector : vals :states (icollect [_ (ipairs vals)] {})})
 
 (fn repl.run [{: listeners}]
   (fennel.repl {:readChunk coroutine.yield
diff --git a/inspector/init.fnl b/inspector/init.fnl
new file mode 100644
index 0000000..9d83900
--- /dev/null
+++ b/inspector/init.fnl
@@ -0,0 +1,68 @@
+(local util (require :lib.util))
+(local style (require :core.style))
+(local {: defmulti : defmethod} (util.require :lib.multimethod))
+(local {: textbutton} (util.require :editor.imstate))
+
+(local inspector (util.hot-table ...))
+
+(fn inspector.best-inspector [v]
+  (var best-inspector nil)
+  (var best-priority -1)
+  (each [inspector {: priority : predicate} (pairs inspector.inspectors)]
+    (when (and (> priority best-priority) (predicate v))
+      (set best-inspector inspector)
+      (set best-priority priority)))
+  best-inspector)
+
+(set inspector.inspect
+  (defmulti (fn [state value view x y w]
+              (when (= state.inspector nil)
+                (set state.inspector (inspector.best-inspector value)))
+              state.inspector) :inspect ...))
+
+(fn inspector.register [name priority predicate inspect-func]
+  (when (= inspector.inspectors nil)
+    (set inspector.inspectors {}))
+  (tset inspector.inspectors name {: predicate : priority :inspector inspect-func})
+  (defmethod inspector.inspect name inspect-func))
+
+(fn inspector.text-height [text ?font]
+  (let [font (or ?font style.code_font)
+        (_ newlines) (text:gsub "\n" "\n")]
+    (* (font:get_height) (+ newlines 1))))
+
+(fn inspector.draw-text [font text x y color]
+  (renderer.draw_text font text x y color)
+  (inspector.text-height text))
+
+(inspector.register :default 0 #true (fn [state value view x y w]
+  (inspector.draw-text style.code_font (fv value) x y style.text)))
+
+(inspector.register :table 10
+  #(and (= (type $1) :table) (not= (next $1) nil))
+  (fn [state tbl view x y w]
+    (local font style.code_font)
+    (var h 0)
+    ; todo: state assumes an .inspector key
+    ; todo: inspector swapping
+    ; todo: edit in place?
+    (fn get-kstate [tbl k state]
+      (when (= nil state.keys) (set state.keys {}))
+      (when (= nil (?. state.keys k))
+        (util.nested-tset state [:keys k] {:collapsed (= (type (. tbl k)) :table) :children {}}))
+      (. state.keys k))
+    (each [k v (pairs tbl)]
+      (let [kstate (get-kstate tbl k state)
+            kstr (fv k)
+            wk (font:get_width kstr)
+            xoffset (+ wk style.padding.x)
+            toggle-collapse (textbutton view kstr x (+ y h))
+            hv (if kstate.collapsed
+                 (inspector.draw-text font "..." (+ x xoffset) (+ y h) style.syntax.comment)
+                 (inspector.inspect kstate.children v view (+ x xoffset) (+ y h) (- w xoffset)))]
+        (when toggle-collapse (set kstate.collapsed (not kstate.collapsed)))
+        (set h (+ h hv style.padding.y))))
+    h))
+
+inspector.hot
+