RosettaCodeData/Task/Assertions/Nemerle/assertions-2.nemerle

using Nemerle.Assertions;

class SampleClass
{
   public SomeMethod (input : list[int]) : int
     requires input.Length > 0                 // requires keyword indicates precondition,
                                                    // there can be more than one condition per method
   { ... }

   public AnotherMethod (input : string) : list[char]
     ensures value.Length > 0                  // ensures keyword indicates postcondition
   { ... }                                     // value is a special symbol that indicates the method's return value
}