Instanceof support for hump class

hump/class.lua

@@ -54,6 +54,8 @@ local function clone(other)
     return setmetatable(include({}, other), getmetatable(other))
 end
 
+local class_id = 1
+
 local function new(class)
     -- mixins
     local inc = class.__includes or {}
@@ -69,6 +71,32 @@ local function new(class)
     class.include = class.include or include
     class.clone   = class.clone   or clone
 
+    if class.class_tree == nil then
+        class.class_tree = {}
+    else
+        table.insert(class.class_tree, class_id)
+    end
+    class.class_id = class_id
+
+    class_id = class_id + 1
+
+    -- Check if object is instance of given class
+    -- Note this will not work for child classes
+    class.isinstance = function(self, class)
+        if self.class_id == class.class_id then
+            return true
+        end
+
+        for _, val in pairs(self.class_tree) do
+            if val == class.class_id then
+                return true
+            end
+        end
+        return false
+    end
+
+    class_id = class_id + 1
+
     -- constructor call
     return setmetatable(class, {__call = function(c, ...)
         local o = setmetatable({}, c)