lib/wlang/scope.rb in wlang-2.0.0.beta vs lib/wlang/scope.rb in wlang-2.0.0

@@ -10,22 +10,30 @@
 
     def self.root
       @root ||= RootScope.new
     end
 
-    def self.coerce(arg, parent = root)
+    def self.coerce(arg, parent = nil)
+      return arg if Scope===arg && parent.nil?
+      parent ||= root
       clazz = case arg
-      when Binding
-        BindingScope
-      when Scope
-        ProxyScope
-      else
-        ObjectScope
-      end
+              when Binding
+                BindingScope
+              when Scope
+                ProxyScope
+              when Proc
+                ProcScope
+              else
+                ObjectScope
+              end
       clazz.new(arg, parent)
     end
 
+    def self.chain(scopes)
+      scopes.compact.inject(nil){|parent,child| Scope.coerce(child, parent)} || root
+    end
+
     def push(x)
       Scope.coerce(x, self)
     end
 
     def pop
@@ -53,5 +61,6 @@
 end # module WLang
 require 'wlang/scope/root_scope'
 require 'wlang/scope/proxy_scope'
 require 'wlang/scope/object_scope'
 require 'wlang/scope/binding_scope'
+require 'wlang/scope/proc_scope'