Buffer Nexter

About

Buffer Nexter will allow you to manually iterate a buffer based on an arbitrary separator (defaulting to \n). Alternatively, you can stream the buffer based on the same separator. The next() method behaves very similarly to an ES6 generator.

Use

import BufferNexter from 'buffer-nexter';

let lines = new Buffer('line1\nline2\line3');

let buf = new BufferNexter(lines);

console.log(buf.next()); // -> line1
console.log(buf.next()); // -> line2
console.log(buf.next()); // -> line3
console.log(buf.next()); // -> null

Example

let buf = new BufferNexter(buffer[, options]);

buffer (type: Buffer)

A standard buffer, typically a String, containing some value to use as a separator to iterate with.

options (type: Object, optional)

• separator - The string value to use for iteration, default \n.
• index - The buffer index within the buffer to begin iteration, default 0.
• encoding - The encoding type to use to read the buffer, default utf8.

Code

let buf = new BufferNexter('1,2,3', { separator: ',' });

console.log(buf.next()); // -> 1
console.log(buf.next()); // -> 2
console.log(buf.next()); // -> 3
console.log(buf.next()); // -> null

Instance Methods

next()

Calling next() will return the 'next' value from the provided buffer.

• Returns: String or Null

skip(n)

This will call next() 'n' times and return this so you can chain next() calls.

• Returns: this

peek()

This will give you a look at the 'next' value that will be returned on the subsequent next() call.

• Returns: String or Null without iterating

stream()

This returns a Readable stream for piping or whatever you want to use a stream for. The stream emits data events for each iteration of the buffer.

• Returns: Stream.Readable

Static Methods

BufferNexter.readFile(file[, options])

If you just want to read a file and iterate next() calls on \n, then this is the easiest way to do that.

• Returns: Promise -> BufferNexter instance

/* sample.txt
foo
bar
baz
 */

import { readFile } from 'buffer-nexter';

readFile('sample.txt')
  .then((buf) => {
    console.log(buf.next()); // -> foo
    console.log(buf.next()); // -> bar
    console.log(buf.next()); // -> baz
  })

/* sample.csv
foo,bar,baz
 */

import { readFile } from 'buffer-nexter';

readFile('sample.csv', { separator: ',' })
  .then((buf) => {
    console.log(buf.next()); // -> foo
    console.log(buf.next()); // -> bar
    console.log(buf.next()); // -> baz
  })

What about readFileSync()? If there's a demand for it or if someone submits a PR, I'll add it, but I prefer to use Promises wherever possible.

Versions

• 0.1.0 - 20151222 - Added static readFile()
• 0.0.1 - 20151221 - Initial release

Credits

• Mark - Thanks for the encouragement!