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|
-module(gleam@order).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function]).
-export([negate/1, to_int/1, compare/2, max/2, min/2, reverse/1]).
-export_type([order/0]).
-type order() :: lt | eq | gt.
-spec negate(order()) -> order().
negate(Order) ->
case Order of
lt ->
gt;
eq ->
eq;
gt ->
lt
end.
-spec to_int(order()) -> integer().
to_int(Order) ->
case Order of
lt ->
-1;
eq ->
0;
gt ->
1
end.
-spec compare(order(), order()) -> order().
compare(A, B) ->
case {A, B} of
{X, Y} when X =:= Y ->
eq;
{lt, _} ->
lt;
{eq, gt} ->
lt;
{_, _} ->
gt
end.
-spec max(order(), order()) -> order().
max(A, B) ->
case {A, B} of
{gt, _} ->
gt;
{eq, lt} ->
eq;
{_, _} ->
B
end.
-spec min(order(), order()) -> order().
min(A, B) ->
case {A, B} of
{lt, _} ->
lt;
{eq, gt} ->
eq;
{_, _} ->
B
end.
-spec reverse(fun((I, I) -> order())) -> fun((I, I) -> order()).
reverse(Orderer) ->
fun(A, B) -> Orderer(B, A) end.
|
