refactor objects

internal/object/environment.go

@@ -4,24 +4,31 @@ import "unicode"
 
 func NewEnclosedEnvironment(outer *Environment) *Environment {
 	env := NewEnvironment()
-	env.outer = outer
+	env.parent = outer
 	return env
 }
 
 func NewEnvironment() *Environment {
 	s := make(map[string]Object)
-	return &Environment{store: s, outer: nil}
+	return &Environment{store: s, parent: nil}
 }
 
 type Environment struct {
-	store map[string]Object
-	outer *Environment
+	store  map[string]Object
+	parent *Environment
+}
+
+// New creates a new copy of the environment with the current environment as parent
+func (e *Environment) New() *Environment {
+	env := NewEnvironment()
+	env.parent = e
+	return env
 }
 
 func (e *Environment) Get(name string) (Object, bool) {
 	obj, ok := e.store[name]
-	if !ok && e.outer != nil {
-		obj, ok = e.outer.Get(name)
+	if !ok && e.parent != nil {
+		obj, ok = e.parent.Get(name)
 	}
 	return obj, ok
 }
@@ -40,7 +47,7 @@ func (e *Environment) ExportedHash() *Hash {
 	for k, v := range e.store {
 		if unicode.IsUpper(rune(k[0])) {
 			s := String{Value: k}
-			pairs[s.HashKey()] = HashPair{Key: s, Value: v}
+			pairs[s.Hash()] = HashPair{Key: s, Value: v}
 		}
 	}
 	return &Hash{Pairs: pairs}