// Dec will decrement a variable.
// args[0] - variable name
// args[1] - quantum of value to decrement
// if variable name is present in local scope it will be used,
// otherwise variable name from global scope is used.
func Dec(scope common.Scope, args ...interface{}) interface{} {
name, by := args[0].(string), int64(1)
if len(args) > 1 {
by = args[1].(int64)
}
vali, g, ok := scope.Get(name)
if ok {
scope.Set(name, vali.(int64)-by, g)
}
return ""
}
