{"id":25473429,"url":"https://github.com/stdlib-js/streams-node-from-constant","last_synced_at":"2026-02-02T11:37:32.292Z","repository":{"id":41423479,"uuid":"377248426","full_name":"stdlib-js/streams-node-from-constant","owner":"stdlib-js","description":"Create a readable stream which always streams the same value.","archived":false,"fork":false,"pushed_at":"2024-12-01T08:58:05.000Z","size":1851,"stargazers_count":1,"open_issues_count":0,"forks_count":0,"subscribers_count":3,"default_branch":"main","last_synced_at":"2025-02-01T07:32:28.609Z","etag":null,"topics":["const","constant","javascript","node","node-js","nodejs","readable","repeat","stdlib","stream","streams","util","utilities","utility","utils"],"latest_commit_sha":null,"homepage":"https://github.com/stdlib-js/stdlib","language":"JavaScript","has_issues":false,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"apache-2.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/stdlib-js.png","metadata":{"files":{"readme":"README.md","changelog":"CHANGELOG.md","contributing":"CONTRIBUTING.md","funding":null,"license":"LICENSE","code_of_conduct":"CODE_OF_CONDUCT.md","threat_model":null,"audit":null,"citation":"CITATION.cff","codeowners":null,"security":"SECURITY.md","support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null},"funding":{"github":["stdlib-js"],"open_collective":"stdlib","tidelift":"npm/@stdlib/stdlib"}},"created_at":"2021-06-15T17:46:55.000Z","updated_at":"2024-12-01T03:53:07.000Z","dependencies_parsed_at":"2023-10-01T07:33:44.991Z","dependency_job_id":"af566067-981f-4283-90b4-69acc535c2da","html_url":"https://github.com/stdlib-js/streams-node-from-constant","commit_stats":{"total_commits":51,"total_committers":1,"mean_commits":51.0,"dds":0.0,"last_synced_commit":"dd4f16d0164dcdc5eb5eebd7dafb403bc110a546"},"previous_names":[],"tags_count":27,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/stdlib-js%2Fstreams-node-from-constant","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/stdlib-js%2Fstreams-node-from-constant/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/stdlib-js%2Fstreams-node-from-constant/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/stdlib-js%2Fstreams-node-from-constant/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/stdlib-js","download_url":"https://codeload.github.com/stdlib-js/streams-node-from-constant/tar.gz/refs/heads/main","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":239449583,"owners_count":19640535,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["const","constant","javascript","node","node-js","nodejs","readable","repeat","stdlib","stream","streams","util","utilities","utility","utils"],"created_at":"2025-02-18T10:21:20.716Z","updated_at":"2026-02-02T11:37:32.286Z","avatar_url":"https://github.com/stdlib-js.png","language":"JavaScript","funding_links":["https://github.com/sponsors/stdlib-js","https://opencollective.com/stdlib","https://tidelift.com/funding/github/npm/@stdlib/stdlib"],"categories":[],"sub_categories":[],"readme":"\u003c!--\n\n@license Apache-2.0\n\nCopyright (c) 2018 The Stdlib Authors.\n\nLicensed under the Apache License, Version 2.0 (the \"License\");\nyou may not use this file except in compliance with the License.\nYou may obtain a copy of the License at\n\n   http://www.apache.org/licenses/LICENSE-2.0\n\nUnless required by applicable law or agreed to in writing, software\ndistributed under the License is distributed on an \"AS IS\" BASIS,\nWITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\nSee the License for the specific language governing permissions and\nlimitations under the License.\n\n--\u003e\n\n\n\u003cdetails\u003e\n  \u003csummary\u003e\n    About stdlib...\n  \u003c/summary\u003e\n  \u003cp\u003eWe believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.\u003c/p\u003e\n  \u003cp\u003eThe library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.\u003c/p\u003e\n  \u003cp\u003eWhen you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.\u003c/p\u003e\n  \u003cp\u003eTo join us in bringing numerical computing to the web, get started by checking us out on \u003ca href=\"https://github.com/stdlib-js/stdlib\"\u003eGitHub\u003c/a\u003e, and please consider \u003ca href=\"https://opencollective.com/stdlib\"\u003efinancially supporting stdlib\u003c/a\u003e. We greatly appreciate your continued support!\u003c/p\u003e\n\u003c/details\u003e\n\n# Constant Stream\n\n[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] \u003c!-- [![dependencies][dependencies-image]][dependencies-url] --\u003e\n\n\u003e Create a [readable stream][readable-stream] which always streams the same value.\n\n\u003csection class=\"installation\"\u003e\n\n## Installation\n\n```bash\nnpm install @stdlib/streams-node-from-constant\n```\n\nAlternatively,\n\n-   To load the package in a website via a `script` tag without installation and bundlers, use the [ES Module][es-module] available on the [`esm`][esm-url] branch (see [README][esm-readme]).\n-   If you are using Deno, visit the [`deno`][deno-url] branch (see [README][deno-readme] for usage intructions).\n-   For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [`umd`][umd-url] branch (see [README][umd-readme]).\n-   To use as a general utility for the command line, install the corresponding [CLI package][cli-section] globally.\n\nThe [branches.md][branches-url] file summarizes the available branches and displays a diagram illustrating their relationships.\n\nTo view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.\n\n\u003c/section\u003e\n\n\u003csection class=\"usage\"\u003e\n\n## Usage\n\n```javascript\nvar constantStream = require( '@stdlib/streams-node-from-constant' );\n```\n\n\u003ca name=\"constant-stream\"\u003e\u003c/a\u003e\n\n#### constantStream( value\\[, options] )\n\nReturns a [readable stream][readable-stream] which **always** streams the **same** `value`.\n\n```javascript\nvar inspectStream = require( '@stdlib/streams-node-inspect-sink' );\n\nvar iStream;\nvar stream;\n\nfunction log( chunk, i ) {\n    console.log( chunk.toString() );\n    if ( i === 10 ) {\n        stream.destroy();\n    }\n}\n\nstream = constantStream( 'beep' );\niStream = inspectStream( log );\n\nstream.pipe( iStream );\n```\n\nThe function accepts the following `options`:\n\n-   **objectMode**: specifies whether a [stream][stream] should operate in [objectMode][object-mode]. Default: `false`.\n-   **encoding**: specifies how `Buffer` objects should be decoded to `strings`. Default: `null`.\n-   **highWaterMark**: specifies the maximum number of bytes to store in an internal buffer before pausing streaming.\n-   **sep**: separator used to join streamed data. This option is only applicable when a stream is **not** in [objectMode][object-mode]. Default: `'\\n'`.\n-   **iter**: number of iterations.\n\nTo set [stream][stream] `options`,\n\n```javascript\nvar opts = {\n    'objectMode': true,\n    'encoding': 'utf8',\n    'highWaterMark': 64\n};\n\nvar stream = constantStream( 'beep', opts );\n```\n\nBy default, the function returns a [stream][stream] which streams an infinite number of values (i.e., the [stream][stream] will **never** end). To limit the number of streamed values, set the `iter` option.\n\n```javascript\nvar inspectStream = require( '@stdlib/streams-node-inspect-sink' );\n\nfunction log( chunk ) {\n    console.log( chunk.toString() );\n}\n\nvar opts = {\n    'iter': 10\n};\n\nvar stream = constantStream( 'beep', opts );\nvar iStream = inspectStream( log );\n\nstream.pipe( iStream );\n```\n\nBy default, when not operating in [objectMode][object-mode], a returned [stream][stream] delineates streamed values using a newline character. To specify an alternative separator, set the `sep` option.\n\n```javascript\nvar inspectStream = require( '@stdlib/streams-node-inspect-sink' );\n\nfunction log( chunk ) {\n    console.log( chunk.toString() );\n}\n\nvar opts = {\n    'iter': 10,\n    'sep': ','\n};\n\nvar stream = constantStream( 'beep', opts );\nvar iStream = inspectStream( log );\n\nstream.pipe( iStream );\n```\n\n* * *\n\n#### constantStream.factory( \\[value, ]\\[options] )\n\nReturns a `function` for creating [readable streams][readable-stream] which **always** stream the **same** provided `value`.\n\n```javascript\nvar opts = {\n    'objectMode': true,\n    'encoding': 'utf8',\n    'highWaterMark': 64\n};\n\nvar createStream = constantStream.factory( opts );\n```\n\nIf provided a `value` to stream, the returned function returns [readable streams][readable-stream] which **always** stream the **same** `value`.\n\n```javascript\nvar createStream = constantStream.factory( 'beep' );\n\nvar stream1 = createStream();\nvar stream2 = createStream();\n// ...\n```\n\nIf not provided a `value` to stream, the returned function requires that a `value` be provided at each invocation.\n\n```javascript\nvar createStream = constantStream.factory();\n\nvar stream1 = createStream( 'beep' );\nvar stream2 = createStream( 'boop' );\n// ...\n```\n\nThe method accepts the same `options` as [`constantStream()`](#constant-stream).\n\n* * *\n\n#### constantStream.objectMode( value\\[, options] )\n\nThis method is a convenience function to create [streams][stream] which **always** operate in [objectMode][object-mode].\n\n```javascript\nvar inspectStream = require( '@stdlib/streams-node-inspect-sink' );\n\nfunction log( v ) {\n    console.log( v );\n}\n\nvar value = {\n    'beep': 'boop'\n};\nvar opts = {\n    'iter': 10\n};\nvar stream = constantStream.objectMode( value, opts );\n\nopts = {\n    'objectMode': true\n};\nvar iStream = inspectStream( opts, log );\n\nstream.pipe( iStream );\n```\n\nThis method accepts the same `options` as [`constantStream()`](#constant-stream); however, the method will **always** override the [`objectMode`][object-mode] option in `options`.\n\n\u003c/section\u003e\n\n\u003c!-- /.usage --\u003e\n\n* * *\n\n\u003csection class=\"notes\"\u003e\n\n## Notes\n\n-   In binary mode, a provided `value` must be a `string`, `Buffer`, or `Uint8Array`.\n-   In [`objectMode`][object-mode], `null` is a reserved value. If provided `null`, the returned [stream][stream] will prematurely end.\n-   If provided an `object` reference, the `value` is **not** copied. To avoid unwanted mutation, copy the `value` **before** creating a [stream][stream].\n-   In older Node.js environments, `Uint8Array` contents may be copied to a new `Buffer` object due to changes in the underlying Node.js APIs.\n-   If the `factory` method is provided only one argument and that argument is an `object` (either empty or not containing any recognized `options` properties), the method treats the argument as a value to be streamed, **not** as an `options` argument.\n\n\u003c/section\u003e\n\n\u003c!-- /.notes --\u003e\n\n* * *\n\n\u003csection class=\"examples\"\u003e\n\n## Examples\n\n\u003c!-- eslint no-undef: \"error\" --\u003e\n\n```javascript\nvar inspectStream = require( '@stdlib/streams-node-inspect-sink' );\nvar constantStream = require( '@stdlib/streams-node-from-constant' );\n\nfunction log( v ) {\n    console.log( v.toString() );\n}\n\nvar opts = {\n    'objectMode': true,\n    'iter': 10\n};\n\nvar stream = constantStream( 3.14, opts );\n\nopts = {\n    'objectMode': true\n};\nvar iStream = inspectStream( opts, log );\n\nstream.pipe( iStream );\n```\n\n\u003c/section\u003e\n\n\u003c!-- /.examples --\u003e\n\n\u003c!-- Section for describing a command-line interface. --\u003e\n\n* * *\n\n\u003csection class=\"cli\"\u003e\n\n## CLI\n\n\u003csection class=\"installation\"\u003e\n\n## Installation\n\nTo use as a general utility, install the CLI package globally\n\n```bash\nnpm install -g @stdlib/streams-node-from-constant-cli\n```\n\n\u003c/section\u003e\n\u003c!-- CLI usage documentation. --\u003e\n\n\n\u003csection class=\"usage\"\u003e\n\n### Usage\n\n```text\nUsage: constant-stream [options] \u003cvalue\u003e\n\nOptions:\n\n  -h,  --help               Print this message.\n  -V,  --version            Print the package version.\n       --sep sep            Separator used to join streamed data. Default: '\\n'.\n  -n,  --iter iterations    Number of iterations.\n```\n\n\u003c/section\u003e\n\n\u003c!-- /.usage --\u003e\n\n\u003c!-- CLI usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. --\u003e\n\n\u003csection class=\"notes\"\u003e\n\n### Notes\n\n-   In accordance with POSIX convention, a trailing newline is **always** appended to generated output prior to exit.\n\n\u003c/section\u003e\n\n\u003c!-- /.notes --\u003e\n\n\u003c!-- CLI usage examples. --\u003e\n\n\u003csection class=\"examples\"\u003e\n\n### Examples\n\n```bash\n$ constant-stream 'beep' -n 10\n```\n\n\u003c/section\u003e\n\n\u003c!-- /.examples --\u003e\n\n\u003c/section\u003e\n\n\u003c!-- /.cli --\u003e\n\n\u003c!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. --\u003e\n\n\u003csection class=\"related\"\u003e\n\n* * *\n\n## See Also\n\n-   \u003cspan class=\"package-name\"\u003e[`@stdlib/streams-node/from-array`][@stdlib/streams/node/from-array]\u003c/span\u003e\u003cspan class=\"delimiter\"\u003e: \u003c/span\u003e\u003cspan class=\"description\"\u003ecreate a readable stream from an array-like object.\u003c/span\u003e\n-   \u003cspan class=\"package-name\"\u003e[`@stdlib/streams-node/from-iterator`][@stdlib/streams/node/from-iterator]\u003c/span\u003e\u003cspan class=\"delimiter\"\u003e: \u003c/span\u003e\u003cspan class=\"description\"\u003ecreate a readable stream from an iterator.\u003c/span\u003e\n\n\u003c/section\u003e\n\n\u003c!-- /.related --\u003e\n\n\u003c!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. --\u003e\n\n\n\u003csection class=\"main-repo\" \u003e\n\n* * *\n\n## Notice\n\nThis package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.\n\nFor more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].\n\n#### Community\n\n[![Chat][chat-image]][chat-url]\n\n---\n\n## License\n\nSee [LICENSE][stdlib-license].\n\n\n## Copyright\n\nCopyright \u0026copy; 2016-2026. The Stdlib [Authors][stdlib-authors].\n\n\u003c/section\u003e\n\n\u003c!-- /.stdlib --\u003e\n\n\u003c!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. --\u003e\n\n\u003csection class=\"links\"\u003e\n\n[npm-image]: http://img.shields.io/npm/v/@stdlib/streams-node-from-constant.svg\n[npm-url]: https://npmjs.org/package/@stdlib/streams-node-from-constant\n\n[test-image]: https://github.com/stdlib-js/streams-node-from-constant/actions/workflows/test.yml/badge.svg?branch=main\n[test-url]: https://github.com/stdlib-js/streams-node-from-constant/actions/workflows/test.yml?query=branch:main\n\n[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/streams-node-from-constant/main.svg\n[coverage-url]: https://codecov.io/github/stdlib-js/streams-node-from-constant?branch=main\n\n\u003c!--\n\n[dependencies-image]: https://img.shields.io/david/stdlib-js/streams-node-from-constant.svg\n[dependencies-url]: https://david-dm.org/stdlib-js/streams-node-from-constant/main\n\n--\u003e\n\n[chat-image]: https://img.shields.io/badge/zulip-join_chat-brightgreen.svg\n[chat-url]: https://stdlib.zulipchat.com\n\n[stdlib]: https://github.com/stdlib-js/stdlib\n\n[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors\n\n[cli-section]: https://github.com/stdlib-js/streams-node-from-constant#cli\n[cli-url]: https://github.com/stdlib-js/streams-node-from-constant/tree/cli\n[@stdlib/streams-node-from-constant]: https://github.com/stdlib-js/streams-node-from-constant/tree/main\n\n[umd]: https://github.com/umdjs/umd\n[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules\n\n[deno-url]: https://github.com/stdlib-js/streams-node-from-constant/tree/deno\n[deno-readme]: https://github.com/stdlib-js/streams-node-from-constant/blob/deno/README.md\n[umd-url]: https://github.com/stdlib-js/streams-node-from-constant/tree/umd\n[umd-readme]: https://github.com/stdlib-js/streams-node-from-constant/blob/umd/README.md\n[esm-url]: https://github.com/stdlib-js/streams-node-from-constant/tree/esm\n[esm-readme]: https://github.com/stdlib-js/streams-node-from-constant/blob/esm/README.md\n[branches-url]: https://github.com/stdlib-js/streams-node-from-constant/blob/main/branches.md\n\n[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/streams-node-from-constant/main/LICENSE\n\n[stream]: https://nodejs.org/api/stream.html\n\n[object-mode]: https://nodejs.org/api/stream.html#stream_object_mode\n\n[readable-stream]: https://nodejs.org/api/stream.html\n\n\u003c!-- \u003crelated-links\u003e --\u003e\n\n[@stdlib/streams/node/from-array]: https://github.com/stdlib-js/streams-node-from-array\n\n[@stdlib/streams/node/from-iterator]: https://github.com/stdlib-js/streams-node-from-iterator\n\n\u003c!-- \u003c/related-links\u003e --\u003e\n\n\u003c/section\u003e\n\n\u003c!-- /.links --\u003e\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fstdlib-js%2Fstreams-node-from-constant","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fstdlib-js%2Fstreams-node-from-constant","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fstdlib-js%2Fstreams-node-from-constant/lists"}