pipu

Pipu

🔥 hellishly fast, 🤏 tiny and 🤖 modular async/sync pipe toolkit for typescript.

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Installation

yarn add pipu # pnpm add pipu

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Concept

Pipu is designed to be as low-level and unopinionated as possible so you can build your own abstractions on top of it.

It supports both sync and async modes. That means you can use sync to solve problems where sync fits the job best and async where async fits the job best.

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Examples

1. Map
2. Filter
3. Or
4. Wrap
5. Parse
6. Resolve

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Pipeables

Pipeables are functions that you can put into a pipe (pipe itself is Pipeable).

There's just a few core pipeables so it's easy to build your own abstractions on top them.

(but I'm open to ideas and PRs regarding new pipeables)

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)),
);

resolve

Async pipeable which tries to resolve a promise and return ResultOk.

// PipeableAsync<number, Result<number, Error<"PROMISE", number>>>
const getUsersByAge = and(
  filter((age: number) => age > 18),
  resolve((age) => api.getUsersByAge(age)),
);

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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 Pipeables 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);

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Have a beautiful day 🍀.