assignment 2.11

a211.erl

% Marcelo Ruiz Camauër
% assignment 2.11

% Define a function take that takes the first N elements from a list.

-module(a211).
-export([take/2]).
-include_lib("eunit/include/eunit.hrl").
-spec take(integer(),[L]) -> [L].

take(_,[]) -> [];
take(0,[_]) -> [];
take(N,[H|T]) -> 
    case N of
        0 -> [];
        1 -> [H];
        N -> [H]++take(N-1,T)
    end.

%%%%%%%%%%%%%%% TESTS %%%%%%%%%%
% invoke with 'a211:tests().' or "eunit:test(a211)."
take_test_()->
     [?_assert(take(0,"hello")==[]),
      ?_assert(take(4,"hello")=="hell"),
      ?_assert(take(5,"hello")=="hello"),
      ?_assert(take(9,"hello")=="hello")
    ].