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create_double

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

Installation

npm install @stdlib/napi-create-double

Usage

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>

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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_env environment under which the function is invoked.
• value: [in] double double-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.

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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

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License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.