gistfile1.erl

-module(wm). % wrap math

-compile(export_all).





%% 2> c("/projects/scratch/wm.erl").
%% {ok,wm}
%% 
%% 3> wm:one().                     
%% #Fun<wm.0.45968298>
%% 
%% 4> F = wm:one().
%% #Fun<wm.0.45968298>
%% 
%% 5> F().
%% 1
%% 
%% 6> G = wm:triple(wm:one()).
%% #Fun<wm.1.45968298>
%% 
%% 7> G().
%% 3
%% 
%% 8> H = wm:triple(wm:triple(wm:one())).
%% #Fun<wm.1.45968298>
%% 
%% 9> H().
%% 9
%% 
%% 10> I = wm:triple(wm:add_two(wm:triple(wm:one()))).
%% #Fun<wm.1.45968298>
%% 
%% 11> I().
%% 15





one() -> fun() -> 1 end.





const_multiply(Const, Wrapped) ->
    fun() -> Const * Wrapped() end.



double(Wrapped) -> 
    const_multiply(2, Wrapped).

triple(Wrapped) -> 
    const_multiply(3, Wrapped).





const_add(Const, Wrapped) ->
    fun() -> Const + Wrapped() end.



add_two(Wrapped) -> 
    const_add(2, Wrapped).

subtract_three(Wrapped) -> 
    const_add(2, Wrapped).