string

String manipulation streams — split, replace, count, and measure text data.

Install

npm install @datastream/string

stringReadableStream Readable

Creates a Readable stream from a string input.

import { stringReadableStream } from '@datastream/string'

const stream = stringReadableStream('hello world')

stringLengthStream PassThrough

Counts the total character length of all chunks.

Options

Option	Type	Default	Description
resultKey	string	"length"	Key in pipeline result

Example

import { pipeline, createReadableStream } from '@datastream/core'
import { stringLengthStream } from '@datastream/string'

const length = stringLengthStream()
const result = await pipeline([
  createReadableStream('hello world'),
  length,
])

console.log(result)
// { length: 11 }

stringCountStream PassThrough

Counts occurrences of a substring across all chunks.

Options

Option	Type	Default	Description
substr	string	—	Substring to count
resultKey	string	"count"	Key in pipeline result

Example

import { pipeline, createReadableStream } from '@datastream/core'
import { stringCountStream } from '@datastream/string'

const count = stringCountStream({ substr: '\n' })
const result = await pipeline([
  createReadableStream('line1\nline2\nline3'),
  count,
])

console.log(result)
// { count: 2 }

stringSplitStream Transform

Splits streaming text by a separator, emitting one chunk per segment. Handles splits that cross chunk boundaries.

Options

Option	Type	Default	Description
separator	string	—	String to split on

Example

import { pipeline, createReadableStream, streamToArray, pipejoin } from '@datastream/core'
import { stringSplitStream } from '@datastream/string'

const river = pipejoin([
  createReadableStream('alice,bob,charlie'),
  stringSplitStream({ separator: ',' }),
])

const output = await streamToArray(river)
// ['alice', 'bob', 'charlie']

stringReplaceStream Transform

Replaces pattern matches in streaming text. Handles replacements that span chunk boundaries.

Options

Option	Type	Default	Description
pattern	string \| RegExp	—	Pattern to search for
replacement	string	—	Replacement string

Example

import { stringReplaceStream } from '@datastream/string'

stringReplaceStream({ pattern: /\t/g, replacement: ',' })

stringMinimumFirstChunkSize Transform

Buffers data until the first chunk meets a minimum size, then passes all subsequent chunks through unchanged.

Options

Option	Type	Default	Description
chunkSize	number	1024	Minimum first chunk size in characters

stringMinimumChunkSize Transform

Buffers data until chunks meet a minimum size before emitting. Useful when downstream requires a minimum data size for processing.

Options

Option	Type	Default	Description
chunkSize	number	1024	Minimum chunk size in characters

stringSkipConsecutiveDuplicates Transform

Skips consecutive duplicate string chunks.

import { stringSkipConsecutiveDuplicates } from '@datastream/string'

// Input chunks: 'a', 'a', 'b', 'a' → Output: 'a', 'b', 'a'