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retired
A standard library for the Gleam programming language
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Files
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Files
src/gleam@option.erl
-module(gleam@option).
-compile(no_auto_import).
-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(AHW) :: {some, AHW} | none.
-spec all(list(option(AHX))) -> option(list(AHX)).
all(List) ->
gleam@list:fold_right(
List,
{some, []},
fun(Acc, Item) -> case {Acc, Item} of
{{some, Values}, {some, Value}} ->
{some, [Value | Values]};
{_@1, _@2} ->
none
end end
).
-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(AIG), AIJ) -> {ok, AIG} | {error, AIJ}.
to_result(Option, E) ->
case Option of
{some, A} ->
{ok, A};
_@1 ->
{error, E}
end.
-spec from_result({ok, AIM} | {error, any()}) -> option(AIM).
from_result(Result) ->
case Result of
{ok, A} ->
{some, A};
_@1 ->
none
end.
-spec unwrap(option(AIR), AIR) -> AIR.
unwrap(Option, Default) ->
case Option of
{some, X} ->
X;
none ->
Default
end.
-spec lazy_unwrap(option(AIT), fun(() -> AIT)) -> AIT.
lazy_unwrap(Option, Default) ->
case Option of
{some, X} ->
X;
none ->
Default()
end.
-spec map(option(AIV), fun((AIV) -> AIX)) -> option(AIX).
map(Option, Fun) ->
case Option of
{some, X} ->
{some, Fun(X)};
none ->
none
end.
-spec flatten(option(option(AIZ))) -> option(AIZ).
flatten(Option) ->
case Option of
{some, X} ->
X;
none ->
none
end.
-spec then(option(AJD), fun((AJD) -> option(AJF))) -> option(AJF).
then(Option, Fun) ->
case Option of
{some, X} ->
Fun(X);
none ->
none
end.
-spec 'or'(option(AJI), option(AJI)) -> option(AJI).
'or'(First, Second) ->
case First of
{some, _@1} ->
First;
none ->
Second
end.
-spec lazy_or(option(AJM), fun(() -> option(AJM))) -> option(AJM).
lazy_or(First, Second) ->
case First of
{some, _@1} ->
First;
none ->
Second()
end.
-spec values(list(option(AJQ))) -> list(AJQ).
values(Options) ->
gleam@list:filter_map(Options, fun(Op) -> to_result(Op, <<""/utf8>>) end).