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|
-module(order).
-compile(no_auto_import).
-include_lib("eunit/include/eunit.hrl").
-export([reverse/1, to_int/1, compare/2, max/2, min/2]).
reverse(Order) ->
case Order of
lt ->
gt;
eq ->
eq;
gt ->
lt
end.
-ifdef(TEST).
reverse_test() ->
expect:equal(reverse(lt), gt),
expect:equal(reverse(eq), eq),
expect:equal(reverse(gt), lt).
-endif.
to_int(Order) ->
case Order of
lt ->
-1;
eq ->
0;
gt ->
1
end.
-ifdef(TEST).
to_int_test() ->
expect:equal(to_int(lt), -1),
expect:equal(to_int(eq), 0),
expect:equal(to_int(gt), 1).
-endif.
compare(A, B) ->
case {A, B} of
{lt, lt} ->
eq;
{lt, _} ->
lt;
{eq, eq} ->
eq;
{gt, gt} ->
eq;
{eq, gt} ->
lt;
_ ->
gt
end.
-ifdef(TEST).
compare_test() ->
expect:equal(compare(lt, lt), eq),
expect:equal(compare(lt, eq), lt),
expect:equal(compare(lt, gt), lt),
expect:equal(compare(eq, lt), gt),
expect:equal(compare(eq, eq), eq),
expect:equal(compare(eq, gt), lt),
expect:equal(compare(gt, lt), gt),
expect:equal(compare(gt, eq), gt),
expect:equal(compare(gt, gt), eq).
-endif.
max(A, B) ->
case {A, B} of
{gt, _} ->
gt;
{eq, lt} ->
eq;
_ ->
B
end.
-ifdef(TEST).
max_test() ->
expect:equal(max(lt, lt), lt),
expect:equal(max(lt, eq), eq),
expect:equal(max(lt, gt), gt),
expect:equal(max(eq, lt), eq),
expect:equal(max(eq, eq), eq),
expect:equal(max(eq, gt), gt),
expect:equal(max(gt, lt), gt),
expect:equal(max(gt, eq), gt),
expect:equal(max(gt, gt), gt).
-endif.
min(A, B) ->
case {A, B} of
{lt, _} ->
lt;
{eq, gt} ->
eq;
_ ->
B
end.
-ifdef(TEST).
min_test() ->
expect:equal(min(lt, lt), lt),
expect:equal(min(lt, eq), lt),
expect:equal(min(lt, gt), lt),
expect:equal(min(eq, lt), lt),
expect:equal(min(eq, eq), eq),
expect:equal(min(eq, gt), eq),
expect:equal(min(gt, lt), lt),
expect:equal(min(gt, eq), eq),
expect:equal(min(gt, gt), gt).
-endif.
|
