EEP37 shell example

gistfile1.txt

$ $ERL_TOP/bin/erl
Erlang R15B03 (erts-5.9.3) [source] [smp:8:8] [async-threads:0] [hipe] [kernel-poll:false]

Eshell V5.9.3  (abort with ^G)
1> F = fun Myself(N) ->                                    
1>             G = fun Fact(1) ->                          
1>                         1;                              
1>                     Fact(N) when is_integer(N), N > 1 ->
1>                         N * Fact(N - 1);                
1>                     Fact(_) ->                          
1>                         Myself                          
1>                 end,                                    
1>             G(N)                                        
1>     end.                                                
#Fun<erl_eval.6.1798967>
2> F(1).
1
3> F(4).
24
4> F(foo).
#Fun<erl_eval.6.1798967>
5>