| 1 | -module(hope_result). |
| 2 | |
| 3 | |
| 4 | -export_type( |
| 5 | [ t/2 |
| 6 | ]). |
| 7 | |
| 8 | -export( |
| 9 | [ pipe/2 |
| 10 | , lift_exn/1 |
| 11 | ]). |
| 12 | |
| 13 | |
| 14 | -type t(A, B) :: |
| 15 | {ok, A} |
| 16 | | {error, B} |
| 17 | . |
| 18 | |
| 19 | |
| 20 | -spec pipe([F], X) -> |
| 21 | t(Ok, Error) |
| 22 | when X :: any() |
| 23 | , Ok :: any() |
| 24 | , Error :: any() |
| 25 | , F :: fun((X) -> t(Ok, Error)) |
| 26 | . |
| 27 | pipe([], X) -> |
| 28 | {ok, X}; |
| 29 | pipe([F|Fs], X) -> |
| 30 | case F(X) |
| 31 | of {error, _}=E -> E |
| 32 | ; {ok, Y} -> pipe(Fs, Y) |
| 33 | end. |
| 34 | |
| 35 | -spec lift_exn(F) -> G |
| 36 | when F :: fun((A)-> B) |
| 37 | , G :: fun((A)-> t(B, {Class, Reason :: any()})) |
| 38 | , Class :: error |
| 39 | | exit |
| 40 | | throw |
| 41 | . |
| 42 | lift_exn(F) when is_function(F, 1) -> |
| 43 | fun(X) -> |
| 44 | try |
| 45 | {ok, F(X)} |
| 46 | catch Class:Reason -> |
| 47 | {error, {Class, Reason}} |
| 48 | end |
| 49 | end. |