@stdlib/napi-argv-float

About stdlib...

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.

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.

When 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.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

argv_float

Convert a Node-API value to a single-precision floating-point number.

Installation

npm install @stdlib/napi-argv-float

Usage

var headerDir = require( '@stdlib/napi-argv-float' );

headerDir

Absolute file path for the directory containing header files for C APIs.

var dir = headerDir;
// returns <string>

Examples

var headerDir = require( '@stdlib/napi-argv-float' );

console.log( headerDir );
// => <string>

---

C APIs

Usage

#include "stdlib/napi/argv_float.h"

stdlib_napi_argv_float( env, value, *out, *message, *err )

Converts a Node-API value to a single-precision floating-point number.

#include "stdlib/napi/argv_float.h"
#include <node_api.h>

static napi_value addon( napi_env env, napi_callback_info info ) {
    napi_value value;

    // ...

    float out;
    napi_value err;
    napi_status status = stdlib_napi_argv_float( env, value, &out, "Must be a number.", &err );
    assert( status == napi_ok );
    if ( err != NULL ) {
        assert( napi_throw( env, err ) == napi_ok );
        return NULL;
    }

    // ...
}

The function accepts the following arguments:

• env: [in] napi_env environment under which the function is invoked.
• value: [in] napi_value Node-API value.
• out: [out] float* destination for storing output value.
• message: [in] char* error message.
• err: [out] napi_value* pointer for storing a JavaScript error. If not provided a number, the function sets err with a JavaScript error; otherwise, err is set to NULL.

napi_status stdlib_napi_argv_float( const napi_env env, const napi_value value, float *out, const char *message, napi_value *err );

The function returns a napi_status status code indicating success or failure (returns napi_ok if success).

STDLIB_NAPI_ARGV_FLOAT( env, name, argv, index )

Macro for converting an add-on callback argument to a single-precision floating-point number.

#include "stdlib/napi/argv_float.h"
#include "stdlib/napi/argv.h"
#include <node_api.h>

static float fcn( const float v ) {
    return v;
}

// ...

static napi_value addon( napi_env env, napi_callback_info info ) {
    // Retrieve add-on callback arguments:
    STDLIB_NAPI_ARGV( env, info, argv, argc, 1 );

    // Convert the first argument to a C type:
    STDLIB_NAPI_ARGV_FLOAT( env, value, argv, 0 );

    // ...

    float out = fcn( value );
}

The macro expects the following arguments:

• env: environment under which the callback is invoked.
• name: output variable name.
• argv: name of the variable containing add-on callback arguments.
• index: argument index.

---

Notice

This package is part of 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, see the main project repository.

Community

---

License

See LICENSE.

Copyright

Copyright © 2016-2023. The Stdlib Authors.

Changelog

0.1.0 (2023-09-23)

<section class="features">

Features

• 898e8e4 - update minimum TypeScript version

</section> <!-- /.features --> <section class="breaking-changes">

BREAKING CHANGES

• 898e8e4: update minimum TypeScript version to 4.1

  • To migrate, users should upgrade their TypeScript version to at least version 4.1.

</section> <!-- /.breaking-changes --> <section class="commits">

Commits

<details>

• 898e8e4 - feat: update minimum TypeScript version (by Philipp Burckhardt)

</details> </section> <!-- /.commits --> <section class="contributors">

Contributors

A total of 1 person contributed to this release. Thank you to this contributor:

• Philipp Burckhardt

</section> <!-- /.contributors --> </section> <!-- /.release -->