-module(funs_from_outside).
-export([run1/2, run2/2, run3/2]).
-export([test1/1, test2/1]).
%%------------------------------------------------------------------------------
run1(X, Y) ->
testa(fun do_something/1, X, Y).
testa(Fun, X, Y) ->
F = case even(X) of
true -> Fun;
false -> fun do_nothing/1
end,
case F(Y) of
{ok, _} -> ok;
error -> error
end.
do_nothing(_) -> {ok, nothing}.
do_something(_) -> {ok, something}.
even(X) ->
X rem 2 =:= 0.
%%------------------------------------------------------------------------------
%% Duplicating code since we are monovariant...
run2(X, Y) ->
testb(fun do_something/1, X, Y).
testb(Fun, X, Y) ->
F = case even(X) of
true -> Fun;
false -> fun do_nothing/1
end,
case F(Y) of
error -> error
end.
%%------------------------------------------------------------------------------
%% Duplicating code since we are monovariant...
run3(X, Y) ->
testc(fun do_something_2/1, X, Y).
testc(Fun, X, Y) ->
F = case even(X) of
true -> Fun;
false -> fun do_nothing/1
end,
case F(Y) of
{ok, _} -> ok;
%% This pattern can match.
error -> error
end.
do_something_2(foo) -> {ok, something};
do_something_2(_) -> error.
%%------------------------------------------------------------------------------
test1(Fun) ->
F = case get(test1) of
test1_t -> Fun;
test1_f -> fun fok/0
end,
error = F().
fok() -> ok.
%%------------------------------------------------------------------------------
test2(Fun) ->
F = case get(test1) of
test1_t -> fun fok/0;
test1_f -> fun fok/0
end,
error = F().
