line-observer

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API

• byLine
• createCharObservable
• parseBy

byline

import byLine from 'line-observer'

const file = 'path/to/file'

/**
file === `
a line
another one!
`
*/

const lines$ = byLine(file) // Observable of lines

lines$.subscribe(console.log) // a line, another one!

This is the main export of this package and returns an Observable of each line read. It shouldn't be read all into memory but instead read character by character.

createCharObservable

import { createCharObservable } from 'line-observer'


const bySpace = createCharObservable((char, strBuffer) => char === '\s')

/**
file === `
a line
another one!
`
*/
const words$ = bySpace(file) // Observable of words

words$.subscribe(console.log) // a, line, another, one!

Returns a function that expects a file path and returns an observable, emitting at each character that passes the function given.

parseBy

import byLine from 'line-observer'

const { parseBy } = byLine

const groupByTab = parseBy('\t')

const parsedLines$ = groupByTab(byLine(file))

/**
file === `
header1  header2
tim1  tim2
tim3  tim4
`
*/

parsedLines$
  .subscribe(console.log) // { header1: tim1, header2: tim2 }, { header1: tim3, header2: tim4 }

Creates a function that expects an observable that emits parsed lines, attaching the headers to each line following.