Packages
gleam_stdlib
0.30.2
1.0.3
1.0.2
1.0.1
1.0.0
0.71.0
0.70.0
0.69.0
0.68.1
0.68.0
0.67.1
0.67.0
0.65.0
0.64.0
0.63.2
0.63.1
0.63.0
0.62.1
0.62.0
0.61.0
0.60.0
0.59.0
0.58.0
0.57.0
0.56.0
0.55.0
0.54.0
0.53.0
0.52.0
0.51.0
0.50.0
0.49.0
0.48.0
0.47.0
0.46.0
0.45.0
0.44.0
0.43.0
0.42.0
0.41.0
0.40.0
0.39.0
0.38.0
0.37.0
0.36.0
0.35.1
0.35.0
0.34.0
0.33.1
0.33.0
0.32.1
0.32.0
0.31.0
0.30.2
0.30.1
0.30.0
0.29.2
0.29.1
0.29.0
0.28.2
0.28.1
0.28.0
0.27.0
0.26.1
0.26.0
0.25.0
0.24.0
0.23.0
0.22.3
0.22.2
0.22.1
0.22.0
0.21.0
0.20.0
0.19.3
0.19.2
0.19.1
0.19.0
0.18.1
0.18.0
0.18.0-rc1
0.17.1
0.17.0
0.16.0
0.15.0
0.14.0
0.13.0
0.12.0
0.11.0
0.10.1
0.10.0
0.9.0
0.8.0
0.7.0
0.6.0
0.5.0
0.4.0
0.4.0-rc1
0.3.1
0.3.0
0.2.0
retired
A standard library for the Gleam programming language
Current section
Files
Jump to
Current section
Files
src/gleam@option.erl
-module(gleam@option).
-compile([no_auto_import, nowarn_unused_vars]).
-export([all/1, is_some/1, is_none/1, to_result/2, from_result/1, unwrap/2, lazy_unwrap/2, map/2, flatten/1, then/2, 'or'/2, lazy_or/2, values/1]).
-export_type([option/1]).
-type option(FV) :: {some, FV} | none.
-spec do_all(list(option(FW)), list(FW)) -> option(list(FW)).
do_all(List, Acc) ->
case List of
[] ->
{some, Acc};
[X | Rest] ->
Accumulate = fun(Acc@1, Item) -> case {Acc@1, Item} of
{{some, Values}, {some, Value}} ->
{some, [Value | Values]};
{_, _} ->
none
end end,
Accumulate(do_all(Rest, Acc), X)
end.
-spec all(list(option(GC))) -> option(list(GC)).
all(List) ->
do_all(List, []).
-spec is_some(option(any())) -> boolean().
is_some(Option) ->
Option /= none.
-spec is_none(option(any())) -> boolean().
is_none(Option) ->
Option =:= none.
-spec to_result(option(GL), GO) -> {ok, GL} | {error, GO}.
to_result(Option, E) ->
case Option of
{some, A} ->
{ok, A};
_ ->
{error, E}
end.
-spec from_result({ok, GR} | {error, any()}) -> option(GR).
from_result(Result) ->
case Result of
{ok, A} ->
{some, A};
_ ->
none
end.
-spec unwrap(option(GW), GW) -> GW.
unwrap(Option, Default) ->
case Option of
{some, X} ->
X;
none ->
Default
end.
-spec lazy_unwrap(option(GY), fun(() -> GY)) -> GY.
lazy_unwrap(Option, Default) ->
case Option of
{some, X} ->
X;
none ->
Default()
end.
-spec map(option(HA), fun((HA) -> HC)) -> option(HC).
map(Option, Fun) ->
case Option of
{some, X} ->
{some, Fun(X)};
none ->
none
end.
-spec flatten(option(option(HE))) -> option(HE).
flatten(Option) ->
case Option of
{some, X} ->
X;
none ->
none
end.
-spec then(option(HI), fun((HI) -> option(HK))) -> option(HK).
then(Option, Fun) ->
case Option of
{some, X} ->
Fun(X);
none ->
none
end.
-spec 'or'(option(HN), option(HN)) -> option(HN).
'or'(First, Second) ->
case First of
{some, _} ->
First;
none ->
Second
end.
-spec lazy_or(option(HR), fun(() -> option(HR))) -> option(HR).
lazy_or(First, Second) ->
case First of
{some, _} ->
First;
none ->
Second()
end.
-spec do_values(list(option(HV)), list(HV)) -> list(HV).
do_values(List, Acc) ->
case List of
[] ->
Acc;
[X | Xs] ->
Accumulate = fun(Acc@1, Item) -> case Item of
{some, Value} ->
[Value | Acc@1];
none ->
Acc@1
end end,
Accumulate(do_values(Xs, Acc), X)
end.
-spec values(list(option(IA))) -> list(IA).
values(Options) ->
do_values(Options, []).