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<details>
  <summary>
    About stdlib...
  </summary>
  <p>We 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.</p>
  <p>The 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.</p>
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  <p>To join us in bringing numerical computing to the web, get started by checking us out on <a href="https://github.com/stdlib-js/stdlib">GitHub</a>, and please consider <a href="https://opencollective.com/stdlib">financially supporting stdlib</a>. We greatly appreciate your continued support!</p>
</details>

# Manifest

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Load a manifest for compiling source files.

<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->

<section class="intro">

</section>

<!-- /.intro -->

<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/utils-library-manifest
```

</section>

<section class="usage">

## Usage

```javascript
var manifest = require( '@stdlib/utils-library-manifest' );
```

#### manifest( filepath, conditions\[, options] )

Loads a manifest for compiling source files.

```javascript
var conditions = {
    'os': 'linux'
};

var conf = manifest( './examples/manifest.json', conditions );
// returns <Object>
```

The function accepts the following `options`:

-   **basedir**: base directory from which to search for dependencies. Default: current working directory.
-   **paths**: path convention. Must be either `'win32'`, `'mixed'`, or `'posix'`. Default: based on host platform.

The default search directory is the current working directory of the calling process. To specify an alternative search directory, set the `basedir` option.

```javascript
var conditions = {
    'os': 'linux'
};

var opts = {
    'basedir': __dirname
};

var conf = manifest( './examples/manifest.json', conditions, opts );
// returns <Object>
```

</section>

<!-- /.usage -->

<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="notes">

## Notes

-   A _manifest_ is a [JSON][json] file having the following fields:

    -   **options**: an `object` containing key-value pairs. Each key corresponds to a field in **confs** and may be used to conditionally select a configuration. Each value corresponds to the key's default value. The value for each field in a provided `conditions` object which has a corresponding field in **options** overrides the default value.

        Option keys are akin to primary keys in relational databases, in the sense that they should be used to uniquely identify a particular configuration. While individual key values may be shared across configurations, each configuration should have a unique combination of key values. Furthermore, default option values considered as a unique set should identify one and only one default configuration.

    -   **fields**: an object `array` where each `object` has the following fields:

        -   **field**: key name corresponding to a field in **confs**.
        -   **resolve**: `boolean` indicating whether to resolve field values as file paths. If `true`, all field values are resolved relative to the manifest file.
        -   **relative**: `boolean` indicating whether to resolve field values as relative file paths. This field is **only** considered when a manifest is a root manifest. If `true`, all field values, including those originating from dependencies, are resolved as relative file paths relative the root manifest.

    -   **confs**: an object `array` where each `object` corresponds to a manifest configuration. Each `object` has the following fields:

        -   **src**: `array` of source files.
        -   **include**: `array` of include directories.
        -   **libraries**: `array` of linked library dependencies.
        -   **libpath**: `array` of linked library paths.
        -   **dependencies**: `array` of package dependencies containing source files.

    An example _manifest_:

    ```text
    {
      "options": {
        "os": "linux"
      },
      "fields": [
        {
          "field": "src",
          "resolve": true,
          "relative": true
        },
        {
          "field": "include",
          "resolve": true,
          "relative": false
        },
        {
          "field": "libraries",
          "resolve": false,
          "relative": false
        },
        {
          "field": "libpath",
          "resolve": true,
          "relative": false
        }
      ],
      "confs": [
        {
          "os": "linux",
          "src": [
            "./src/foo_linux.f",
            "./src/foo_linux.c"
          ],
          "include": [
            "./include"
          ],
          "libraries": [],
          "libpath": [],
          "dependencies": [
            "@stdlib/blas/base/daxpy",
            "@stdlib/blas/base/dasum",
            "@stdlib/blas/base/dcopy"
          ]
        }
      ]
    }   
    ```

-   The function recursively walks the manifest dependency tree to resolve **all** source files, libraries, library paths, and include directories.

-   An input `filepath` may be either a relative or absolute file path. If provided a relative file path, a manifest is resolved relative to the base search directory.

-   If a `conditions` object contains fields which do not correspond to manifest options, those fields are ignored (i.e., the "extra" fields have no effect when filtering manifest configurations). This allows providing a `conditions` object containing fields which only apply to certain subsets of manifest dependencies.

-   If no fields in a `conditions` object have corresponding fields in a manifest's options, the function returns a manifest's default configuration.

</section>

<!-- /.notes -->

<!-- Package usage examples. -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var join = require( 'path' ).join;
var manifest = require( '@stdlib/utils-library-manifest' );

// Resolve the absolute path of the manifest JSON file:
var fpath = join( __dirname, 'examples', 'manifest.json' );

// Specify conditions for determining which configuration to load:
var conditions = {
    'os': 'mac'
};

// Specify options:
var opts = {
    'basedir': __dirname
};

// Load a manifest configuration:
var conf = manifest( fpath, conditions, opts );
console.dir( conf );
```

</section>

<!-- /.examples -->

<!-- Section for describing a command-line interface. -->



<!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="references">

</section>

<!-- /.references -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

## See Also

-   <span class="package-name">[`@stdlib/utils-library-manifest-cli`][@stdlib/utils-library-manifest-cli]</span><span class="delimiter">: </span><span class="description">CLI package for use as a command-line utility.</span>


</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->


<section class="main-repo" >

* * *

## Notice

This 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.

For 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].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2024. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

[@stdlib/utils-library-manifest-cli]: https://www.npmjs.com/package/@stdlib/utils-library-manifest-cli

[npm-image]: http://img.shields.io/npm/v/@stdlib/utils-library-manifest.svg
[npm-url]: https://npmjs.org/package/@stdlib/utils-library-manifest

[test-image]: https://github.com/stdlib-js/utils-library-manifest/actions/workflows/test.yml/badge.svg?branch=v0.2.2
[test-url]: https://github.com/stdlib-js/utils-library-manifest/actions/workflows/test.yml?query=branch:v0.2.2

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/utils-library-manifest/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/utils-library-manifest?branch=main

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-->

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[chat-url]: https://app.gitter.im/#/room/#stdlib-js_stdlib:gitter.im

[stdlib]: https://github.com/stdlib-js/stdlib

[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors

[cli-section]: https://github.com/stdlib-js/utils-library-manifest#cli
[cli-url]: https://github.com/stdlib-js/utils-library-manifest/tree/cli
[@stdlib/utils-library-manifest]: https://github.com/stdlib-js/utils-library-manifest/tree/main

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/utils-library-manifest/main/LICENSE

[json]: http://www.json.org/

</section>

<!-- /.links -->
