Instanceof support for hump class

hump/class.lua

@@ -25,70 +25,98 @@ THE SOFTWARE.
 ]]--
 
 local function include_helper(to, from, seen)
-	if from == nil then
-		return to
-	elseif type(from) ~= 'table' then
-		return from
-	elseif seen[from] then
-		return seen[from]
-	end
+    if from == nil then
+        return to
+    elseif type(from) ~= 'table' then
+        return from
+    elseif seen[from] then
+        return seen[from]
+    end
 
-	seen[from] = to
-	for k,v in pairs(from) do
-		k = include_helper({}, k, seen) -- keys might also be tables
-		if not to[k] then
-			to[k] = include_helper({}, v, seen)
-		end
-	end
-	return to
+    seen[from] = to
+    for k,v in pairs(from) do
+        k = include_helper({}, k, seen) -- keys might also be tables
+        if not to[k] then
+            to[k] = include_helper({}, v, seen)
+        end
+    end
+    return to
 end
 
 -- deeply copies `other' into `class'. keys in `other' that are already
 -- defined in `class' are omitted
 local function include(class, other)
-	return include_helper(class, other, {})
+    return include_helper(class, other, {})
 end
 
 -- returns a deep copy of `other'
 local function clone(other)
-	return setmetatable(include({}, other), getmetatable(other))
+    return setmetatable(include({}, other), getmetatable(other))
 end
 
+local class_id = 1
+
 local function new(class)
-	-- mixins
-	local inc = class.__includes or {}
-	if getmetatable(inc) then inc = {inc} end
+    -- mixins
+    local inc = class.__includes or {}
+    if getmetatable(inc) then inc = {inc} end
 
-	for _, other in ipairs(inc) do
-		include(class, other)
-	end
+    for _, other in ipairs(inc) do
+        include(class, other)
+    end
 
-	-- class implementation
-	class.__index = class
-	class.init    = class.init    or class[1] or function() end
-	class.include = class.include or include
-	class.clone   = class.clone   or clone
+    -- class implementation
+    class.__index = class
+    class.init    = class.init    or class[1] or function() end
+    class.include = class.include or include
+    class.clone   = class.clone   or clone
 
-	-- constructor call
-	return setmetatable(class, {__call = function(c, ...)
-		local o = setmetatable({}, c)
-		o:init(...)
-		return o
-	end})
+    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)
+        o:init(...)
+        return o
+    end})
 end
 
 -- interface for cross class-system compatibility (see https://github.com/bartbes/Class-Commons).
 if class_commons ~= false and not common then
-	common = {}
-	function common.class(name, prototype, parent)
-		return new{__includes = {prototype, parent}}
-	end
-	function common.instance(class, ...)
-		return class(...)
-	end
+    common = {}
+    function common.class(name, prototype, parent)
+        return new{__includes = {prototype, parent}}
+    end
+    function common.instance(class, ...)
+        return class(...)
+    end
 end
 
 
 -- the module
 return setmetatable({new = new, include = include, clone = clone},
-	{__call = function(_,...) return new(...) end})
+    {__call = function(_,...) return new(...) end})