is_a

Author: leafo

moonscript/util.lua

@@ -1,9 +1,23 @@
 local concat = table.concat
 local unpack = unpack or table.unpack
+local type = type
 local moon = {
   is_object = function(value)
     return type(value) == "table" and value.__class
   end,
+  is_a = function(thing, t)
+    if not (type(thing) == "table") then
+      return false
+    end
+    local cls = thing.__class
+    while cls do
+      if cls == t then
+        return true
+      end
+      cls = cls.__parent
+    end
+    return false
+  end,
   type = function(value)
     local base_type = type(value)
     if base_type == "table" then

moonscript/util.moon

@@ -2,10 +2,22 @@
 import concat from table
 
 unpack = unpack or table.unpack
+type = type
 
 moon =
   is_object: (value) -> -- is a moonscript object
     type(value) == "table" and value.__class
+
+  is_a: (thing, t) ->
+    return false unless type(thing) == "table"
+    cls = thing.__class
+    while cls
+      if cls == t
+        return true
+      cls = cls.__parent
+
+    false
+
   type: (value) -> -- the moonscript object class
     base_type = type value
     if base_type == "table"