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std/io/read_lines.ts

Deno standard library
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// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
import { type Reader } from "../types.d.ts";import { BufReader } from "./buf_reader.ts";import { concat } from "../bytes/concat.ts";
/** * Read strings line-by-line from a Reader. * * @example * ```ts * import { readLines } from "https://deno.land/std@$STD_VERSION/io/read_lines.ts"; * import * as path from "https://deno.land/std@$STD_VERSION/path/mod.ts"; * * const filename = path.join(Deno.cwd(), "std/io/README.md"); * let fileReader = await Deno.open(filename); * * for await (let line of readLines(fileReader)) { * console.log(line); * } * ``` */export async function* readLines( reader: Reader, decoderOpts?: { encoding?: string; fatal?: boolean; ignoreBOM?: boolean; },): AsyncIterableIterator<string> { const bufReader = new BufReader(reader); let chunks: Uint8Array[] = []; const decoder = new TextDecoder(decoderOpts?.encoding, decoderOpts); while (true) { const res = await bufReader.readLine(); if (!res) { if (chunks.length > 0) { yield decoder.decode(concat(...chunks)); } break; } chunks.push(res.line); if (!res.more) { yield decoder.decode(concat(...chunks)); chunks = []; } }}