argv_uint32

Convert a Node-API value to an unsigned 32-bit integer.

Usage

var headerDir = require( '@stdlib/napi/argv-uint32' );

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-uint32' );

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

C APIs

Usage

#include "stdlib/napi/argv_uint32.h"

stdlib_napi_argv_uint32( env, value, *out, *message, *err )

Converts a Node-API value to an unsigned 32-bit integer.

#include "stdlib/napi/argv_uint32.h"
#include <node_api.h>
#include <stdint.h>

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

    // ...

    uint32_t out;
    napi_value err;
    napi_status status = stdlib_napi_argv_uint32( 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] uint32_t* 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_uint32( const napi_env env, const napi_value value, uint32_t *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_UINT32( env, name, argv, index )

Macro for converting an add-on callback argument to an unsigned 32-bit integer.

#include "stdlib/napi/argv_uint32.h"
#include "stdlib/napi/argv.h"
#include <node_api.h>
#include <stdint.h>

static uint32_t fcn( const uint32_t 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_UINT32( env, value, argv, 0 );

    // ...

    uint32_t 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.
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