stdlib-js
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!
create_double
Convert a double-precision floating-point number to a Node-API value.
Installation
npm install @stdlib/napi-create-doubleUsage
var headerDir = require( '@stdlib/napi-create-double' );headerDir
Absolute file path for the directory containing header files for C APIs.
var dir = headerDir;
// returns <string>Examples
var headerDir = require( '@stdlib/napi-create-double' );
console.log( headerDir );
// => <string>C APIs
Usage
#include "stdlib/napi/create_double.h"stdlib_napi_create_double( env, value, *out )
Converts a double-precision floating-point number to a Node-API value.
#include "stdlib/napi/create_double.h"
#include <node_api.h>
static napi_value addon( napi_env env, napi_callback_info info ) {
// ...
napi_value value;
napi_status status = stdlib_napi_create_double( env, 1.0, &value );
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_envenvironment under which the function is invoked. - value:
[in] doubledouble-precision floating-point number. - out:
[out] napi_value*destination for storing output value.
napi_status stdlib_napi_create_double( const napi_env env, const double value, napi_value *out );The function returns a napi_status status code indicating success or failure (returns napi_ok if success).
STDLIB_NAPI_CREATE_DOUBLE( env, expression, name )
Macro for converting a double-precision floating-point number to a Node-API value.
#include "stdlib/napi/create_double.h"
#include "stdlib/napi/argv_double.h"
#include "stdlib/napi/argv.h"
#include <node_api.h>
static double fcn( const double 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_DOUBLE( env, value, argv, 0 );
// ...
// Convert a value having a C type to a Node-API value:
STDLIB_NAPI_CREATE_DOUBLE( env, fcn( value ), out );
return out;
}The macro expects the following arguments:
- env: environment under which the callback is invoked.
- expression: expression returning a double-precision floating-point number.
- name: output variable name.
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 © 2016-2024. The Stdlib Authors.