pipem v0.1.7
Powerful TypeScript pipes with focus on size, performance and modularity.
yarn add pipem
Pipeables
Pipeables are functions that you can put into a pipe (pipe itself is Pipeable
).
We try to make the number of core pipeables as low as possible so it's easy to build your own abstractions on top them.
filter
Pipeable which runs either truePipeable
or falsePipeable
based on return value of predicate
.
By default truePipeable
returns Ok<$Input>
and falsePipeable
returns Err<Error<"FILTER", $Input>>
.
filter((v: number) => !(v % 2));
filter(
(v: number) => !(v % 2),
() => ok("even"),
);
filter(
(v: number) => !(v % 2),
() => ok("even"),
() => ok("odd"),
);
map
It maps value from $Input
to $Output
and returns it as Ok<$Output>
.
// Pipeable<number, Result<string, Error>>
const doubleString = map((v: number) => `${v * 2}`);
wrap
Pipeable which wraps a sub-pipeable and overrides its Error
.
It's recommended to use error
function to create a custom Error
.
// Pipeable<number, Result<number, Error<"CUSTOM", number>>>
wrap(
map((v: number) => v * 2),
error("CUSTOM"),
);
and
Pipeable which takes N number of pipeables and returns either Ok
returned by the last pipeable or Err
returned by any of the pipeables.
// Pipeable<number, Result<string, Error<"FILTER", number> | Error<"CUSTOM", number>>>
const customPipe = pipe(
filter((v: number) => !(v % 2)),
wrap(
map((v) => `${v}`),
error("CUSTOM"),
),
);
or
Pipeable which takes N number of pipeables and returns either Ok
returned by any of the pipeables or Err
if none of the pipeables returned Ok
.
// Pipeable<number, Result<number, Error<"OR", number>>>
const customPipe = or(
filter((v: number) => !(v % 2)),
filter((v: number) => !(v % 3)),
);
pipe
Pipe is just and
.
Utils
error
Creates error tuple based on value and potential sub-error.
It should mainly be used in wrap
function as a second parameter.
All Pipeable
s should return error created with this function.
error("TEST", (value, error) => ({ valueType: typeof value, error }));
parse
Allows to run Pipeable
with unknown
input while infering everything else from the Pipeable
as usual.
const isStringOrNumber = pipe(...);
// ResultErr<["OR", [], { }]>
const result1 = parse(isStringOrNumber, []);
// ResultOk<1>
const result2 = parse(isStringOrNumber, 1);
Limitations
and
/pipe
andor
can take only up to 32Pipeable
s- It's still not very clear how to do async
Pipeable
s
Have a beautiful day 🍀.