1 # This file is part of NIT ( http://www.nitlanguage.org ).
3 # Copyright 2004-2008 Jean Privat <jean@pryen.org>
5 # Licensed under the Apache License, Version 2.0 (the "License");
6 # you may not use this file except in compliance with the License.
7 # You may obtain a copy of the License at
9 # http://www.apache.org/licenses/LICENSE-2.0
11 # Unless required by applicable law or agreed to in writing, software
12 # distributed under the License is distributed on an "AS IS" BASIS,
13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 # See the License for the specific language governing permissions and
15 # limitations under the License.
17 # A simple exemple of refinement where a method is added to the integer class.
21 # Calculate the self-th element of the fibonacci sequence.
27 return (self-2
).fibonacci
+ (self-1
).fibonacci
32 # Print usage and exit.
35 print
"Usage: fibonnaci <integer>"
40 if args
.length
!= 1 then
43 print args
.first
.to_i
.fibonacci