clone

vm/vm.go

@@ -156,7 +156,12 @@ func (vm *VM) Run() error {
 			globalIndex := code.ReadUint16(ins[ip+1:])
 			vm.currentFrame().ip += 2
 
-			vm.globals[globalIndex] = vm.pop()
+			ref := vm.pop()
+			if mutable, ok := ref.(object.Mutable); ok {
+				vm.globals[globalIndex] = mutable.Clone()
+			} else {
+				vm.globals[globalIndex] = ref
+			}
 
 		case code.OpAssign:
 			ident := vm.pop()