lang: funcs: Registered functions map should be private

Make the map is private so that the public methods must be used to
access it.

lang/funcs/funcs.go

@@ -24,27 +24,27 @@ import (
 	"github.com/purpleidea/mgmt/lang/interfaces"
 )
 
-// RegisteredFuncs is a global map of all possible funcs which can be used. You
+// registeredFuncs is a global map of all possible funcs which can be used. You
 // should never touch this map directly. Use methods like Register instead. It
 // includes implementations which also satisfy PolyFunc as well.
-var RegisteredFuncs = make(map[string]func() interfaces.Func) // must initialize
+var registeredFuncs = make(map[string]func() interfaces.Func) // must initialize
 
 // Register takes a func and its name and makes it available for use. It is
 // commonly called in the init() method of the func at program startup. There is
 // no matching Unregister function. You may also register functions which
 // satisfy the PolyFunc interface.
 func Register(name string, fn func() interfaces.Func) {
-	if _, exists := RegisteredFuncs[name]; exists {
+	if _, exists := registeredFuncs[name]; exists {
 		panic(fmt.Sprintf("a func named %s is already registered", name))
 	}
 	//gob.Register(fn())
-	RegisteredFuncs[name] = fn
+	registeredFuncs[name] = fn
 }
 
 // Lookup returns a pointer to the function's struct. It may be convertible to a
 // PolyFunc if the particular function implements those additional methods.
 func Lookup(name string) (interfaces.Func, error) {
-	f, exists := RegisteredFuncs[name]
+	f, exists := registeredFuncs[name]
 	if !exists {
 		return nil, fmt.Errorf("not found")
 	}