# FxTS

> A functional programming library for TypeScript/JavaScript with lazy evaluation and concurrency support.

FxTS is a functional library that provides lazy evaluation, concurrent processing, and strong type inference for TypeScript/JavaScript programmers. It follows the Iterable/AsyncIterable protocols.

## Core Concepts

- **Lazy Evaluation**: Defers computation until values are actually needed
- **Pipe Composition**: Compose functions using `pipe()` for readable data transformations
- **Concurrent Processing**: Handle async operations in parallel with `concurrent()`
- **Iteration Protocols**: Full support for Iterable/AsyncIterable standards

## Usage Patterns

### Pipe Style
```ts
import { pipe, map, filter, take, toArray } from "@fxts/core";

pipe(
  [1, 2, 3, 4, 5],
  map(a => a * 2),
  filter(a => a > 4),
  take(2),
  toArray
); // [6, 8]
```

### Chaining Style
```ts
import { fx } from "@fxts/core";

fx([1, 2, 3, 4, 5])
  .map(a => a * 2)
  .filter(a => a > 4)
  .take(2)
  .toArray(); // [6, 8]
```

### Async with Concurrency
```ts
import { pipe, toAsync, map, concurrent, toArray } from "@fxts/core";

await pipe(
  [1, 2, 3, 4],
  toAsync,
  map(async a => await fetchData(a)),
  concurrent(2), // Process 2 items in parallel
  toArray
);
```

## Project Structure

- `src/Lazy/` - Lazy evaluation functions (map, filter, take, etc.)
- `src/*.ts` - Strict/eager evaluation functions (reduce, each, find, etc.)
- `src/Util/` - Utility functions
- `src/types/` - TypeScript type definitions
- `test/` - Test files

## Code Conventions

- All functions support currying (iterable as the last argument)
- Dual implementation supporting both Iterable and AsyncIterable
- JSDoc-style documentation with example code
- Apache 2.0 License

## Key Functions

### Lazy Functions (returns Iterator)

- [append](https://fxts.dev/api/append)
- [chunk](https://fxts.dev/api/chunk)
- [compact](https://fxts.dev/api/compact)
- [compress](https://fxts.dev/api/compress)
- [concat](https://fxts.dev/api/concat)
- [concurrent](https://fxts.dev/api/concurrent)
- [concurrentPool](https://fxts.dev/api/concurrentPool)
- [cycle](https://fxts.dev/api/cycle)
- [difference](https://fxts.dev/api/difference)
- [differenceBy](https://fxts.dev/api/differenceBy)
- [drop](https://fxts.dev/api/drop)
- [dropRight](https://fxts.dev/api/dropRight)
- [dropUntil](https://fxts.dev/api/dropUntil)
- [dropWhile](https://fxts.dev/api/dropWhile)
- [entries](https://fxts.dev/api/entries)
- [filter](https://fxts.dev/api/filter)
- [flat](https://fxts.dev/api/flat)
- [flatMap](https://fxts.dev/api/flatMap)
- [fx](https://fxts.dev/api/fx)
- [intersection](https://fxts.dev/api/intersection)
- [intersectionBy](https://fxts.dev/api/intersectionBy)
- [keys](https://fxts.dev/api/keys)
- [map](https://fxts.dev/api/map)
- [peek](https://fxts.dev/api/peek)
- [pipeLazy](https://fxts.dev/api/pipeLazy)
- [pluck](https://fxts.dev/api/pluck)
- [prepend](https://fxts.dev/api/prepend)
- [range](https://fxts.dev/api/range)
- [reject](https://fxts.dev/api/reject)
- [repeat](https://fxts.dev/api/repeat)
- [reverse](https://fxts.dev/api/reverse)
- [scan](https://fxts.dev/api/scan)
- [slice](https://fxts.dev/api/slice)
- [split](https://fxts.dev/api/split)
- [take](https://fxts.dev/api/take)
- [takeRight](https://fxts.dev/api/takeRight)
- [takeUntil](https://fxts.dev/api/takeUntil)
- [takeUntilInclusive](https://fxts.dev/api/takeUntilInclusive)
- [takeWhile](https://fxts.dev/api/takeWhile)
- [toAsync](https://fxts.dev/api/toAsync)
- [transpose](https://fxts.dev/api/transpose)
- [uniq](https://fxts.dev/api/uniq)
- [uniqBy](https://fxts.dev/api/uniqBy)
- [values](https://fxts.dev/api/values)
- [zip](https://fxts.dev/api/zip)
- [zipWith](https://fxts.dev/api/zipWith)
- [zipWithIndex](https://fxts.dev/api/zipWithIndex)

### Strict Functions (returns value)

- [add](https://fxts.dev/api/add)
- [always](https://fxts.dev/api/always)
- [apply](https://fxts.dev/api/apply)
- [average](https://fxts.dev/api/average) (alias: mean)
- [compactObject](https://fxts.dev/api/compactObject)
- [consume](https://fxts.dev/api/consume)
- [countBy](https://fxts.dev/api/countBy)
- [curry](https://fxts.dev/api/curry)
- [delay](https://fxts.dev/api/delay)
- [each](https://fxts.dev/api/each) (alias: forEach)
- [every](https://fxts.dev/api/every)
- [evolve](https://fxts.dev/api/evolve)
- [find](https://fxts.dev/api/find)
- [findIndex](https://fxts.dev/api/findIndex)
- [fromEntries](https://fxts.dev/api/fromEntries)
- [groupBy](https://fxts.dev/api/groupBy)
- [gt](https://fxts.dev/api/gt)
- [gte](https://fxts.dev/api/gte)
- [head](https://fxts.dev/api/head) (alias: first)
- [identity](https://fxts.dev/api/identity)
- [includes](https://fxts.dev/api/includes) (alias: contains)
- [indexBy](https://fxts.dev/api/indexBy)
- [join](https://fxts.dev/api/join)
- [juxt](https://fxts.dev/api/juxt)
- [last](https://fxts.dev/api/last)
- [lt](https://fxts.dev/api/lt)
- [lte](https://fxts.dev/api/lte)
- [max](https://fxts.dev/api/max)
- [memoize](https://fxts.dev/api/memoize)
- [min](https://fxts.dev/api/min)
- [negate](https://fxts.dev/api/negate)
- [noop](https://fxts.dev/api/noop)
- [not](https://fxts.dev/api/not)
- [nth](https://fxts.dev/api/nth)
- [omit](https://fxts.dev/api/omit)
- [omitBy](https://fxts.dev/api/omitBy)
- [partition](https://fxts.dev/api/partition)
- [pick](https://fxts.dev/api/pick)
- [pickBy](https://fxts.dev/api/pickBy)
- [pipe](https://fxts.dev/api/pipe)
- [pipe1](https://fxts.dev/api/pipe1)
- [prop](https://fxts.dev/api/prop)
- [props](https://fxts.dev/api/props)
- [reduce](https://fxts.dev/api/reduce)
- [reduceLazy](https://fxts.dev/api/reduceLazy)
- [resolveProps](https://fxts.dev/api/resolveProps)
- [size](https://fxts.dev/api/size)
- [some](https://fxts.dev/api/some)
- [sort](https://fxts.dev/api/sort)
- [sortBy](https://fxts.dev/api/sortBy)
- [sum](https://fxts.dev/api/sum)
- [tap](https://fxts.dev/api/tap)
- [throwError](https://fxts.dev/api/throwError)
- [throwIf](https://fxts.dev/api/throwIf)
- [toArray](https://fxts.dev/api/toArray)
- [unicodeToArray](https://fxts.dev/api/unicodeToArray)
- [unless](https://fxts.dev/api/unless)
- [when](https://fxts.dev/api/when)

### Type Guard Functions

- [isArray](https://fxts.dev/api/isArray)
- [isBoolean](https://fxts.dev/api/isBoolean)
- [isDate](https://fxts.dev/api/isDate)
- [isEmpty](https://fxts.dev/api/isEmpty)
- [isNil](https://fxts.dev/api/isNil)
- [isNull](https://fxts.dev/api/isNull)
- [isNumber](https://fxts.dev/api/isNumber)
- [isObject](https://fxts.dev/api/isObject)
- [isString](https://fxts.dev/api/isString)
- [isUndefined](https://fxts.dev/api/isUndefined)

### Utility Functions

- [debounce](https://fxts.dev/api/debounce)
- [shuffle](https://fxts.dev/api/shuffle)

## Docs

- [Official Documentation](https://fxts.dev/api/)
- [Getting Started](https://fxts.dev/getting-started)
- [API Reference](https://fxts.dev/api/)