https://github.com/hackergrrl/collect-transform-stream

create a transform stream that runs a function over all collected elements
https://github.com/hackergrrl/collect-transform-stream

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create a transform stream that runs a function over all collected elements

• Host: GitHub
• URL: https://github.com/hackergrrl/collect-transform-stream
• Owner: hackergrrl
• Created: 2017-03-24T16:53:48.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2017-03-24T17:19:58.000Z (over 7 years ago)
• Last Synced: 2024-09-02T22:18:56.349Z (about 1 month ago)
• Language: JavaScript
• Homepage:
• Size: 2.93 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# collect-transform-stream

> create a transform stream that runs a function over all collected elements

Sometimes you end up in a situation where you have a stream pipeline like

```js

pump(source, transform, destination)

```

but you have another transform function that needs to process all elements in

the stream before passing them on, e.g. filtering duplicates from an unordered

stream:

```js

pump(source, collectAndFilter, transform, destination)

```

`collect-transform-stream` is a tiny module that provides this.

## Usage

```js

var uniq = require('uniq')

var from = require('from2')

var collect = require('concat-stream')

var collectTransform = require('collect-transform-stream')

var source = from.obj(new Array(500).fill(0).map(function () {

  return Math.floor(Math.random() * 10)

}))

var dedupe = collectTransform(function (nums) {

  return uniq(nums)

})

var dest = collect({encoding:'object'}, console.log)

source.pipe(dedupe).pipe(dest)

```

outputs

```

0

1

2

3

4

5

6

7

8

9

```

## API

```js

var collect = require('collect-transform-stream')

```

### collect(fn[, cb])

Create a Transform stream that runs the function `fn` on all incoming objects at

once, then pipes elements individually onward to the next stream in the

pipeline.

Use `return result` to use synchronously; call `cb(err, result)` to use

asynchronously.

## Install

With [npm](https://npmjs.org/) installed, run

```

$ npm install collect-transform-stream

```

## License

ISC