function

JSONL.parseChunk

input: string | ArrayBufferLike | TypedArray<ArrayBufferLike> | DataView<ArrayBuffer>,

start?: number,

end?: number

Parse a JSONL chunk, designed for streaming use.

Never throws on parse errors. Instead, returns whatever values were successfully parsed along with an error property containing the SyntaxError (or null on success). Use read to determine how much input was consumed and done to check if all input was parsed.

When a TypedArray is passed, the bytes are parsed directly without copying if the content is ASCII. Optional start and end parameters select a window of the input without copying. For typed arrays these are byte offsets and read will be a byte offset into the original typed array. For strings these are character offsets and read will be a character offset into the original string.

@param input

The JSONL string or typed array to parse

@param start

Offset to start parsing from (bytes for typed arrays, characters for strings, default: 0)

@param end

Offset to stop parsing at (bytes for typed arrays, characters for strings, default: input length)

@returns

An object with values, read, done, and error properties

let buffer = new Uint8Array(0);
for await (const chunk of stream) {
  buffer = Buffer.concat([buffer, chunk]);
  const { values, read, error } = Bun.JSONL.parseChunk(buffer);
  if (error) throw error;
  for (const value of values) handle(value);
  buffer = buffer.subarray(read);
}

Referenced types

class ArrayBuffer

Represents a raw buffer of binary data, which is used to store data for the different typed arrays. ArrayBuffers cannot be read from or written to directly, but can be passed to a typed array or DataView Object to interpret the raw buffer as needed.

readonly [Symbol.toStringTag]: string
readonly byteLength: number
Read-only. The length of the ArrayBuffer (in bytes).
resize(
newByteLength?: number
): void;
Resizes the ArrayBuffer to the specified size (in bytes).
MDN
resize(
byteLength: number
): ArrayBuffer;
Resize an ArrayBuffer in-place.
slice(
begin: number,
end?: number
): ArrayBuffer;
Returns a section of an ArrayBuffer.
transfer(
newByteLength?: number
): ArrayBuffer;
Creates a new ArrayBuffer with the same byte content as this buffer, then detaches this buffer.
MDN
transferToFixedLength(
newByteLength?: number
): ArrayBuffer;
Creates a new non-resizable ArrayBuffer with the same byte content as this buffer, then detaches this buffer.
MDN

interface ParseChunkResult

The result of Bun.JSONL.parseChunk.

done: boolean
true if all input was consumed successfully. false if the input ends with an incomplete value or a parse error occurred.
error: null | SyntaxError
A SyntaxError if a parse error occurred, otherwise null. Values parsed before the error are still available in values.
read: number
How far into the input was consumed. When the input is a string, this is a character offset. When the input is a TypedArray, this is a byte offset. Use input.slice(read) or input.subarray(read) to get the unconsumed remainder.
values: unknown[]
The successfully parsed JSON values.