argv

C utilities for retrieving Node-API add-on callback arguments.

Installation

npm install @stdlib/napi-argv

Usage

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

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' );

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

C APIs

Usage

#include "stdlib/napi/argv.h"

STDLIB_NAPI_ARGV( env, info, argv, argc, nargs )

Macro for retrieving add-on callback arguments.

#include <node_api.h>

// ...

static napi_value addon( napi_env env, napi_callback_info info ) {
    // Retrieve callback arguments:
    STDLIB_NAPI_ARGV( env, info, argv, argc, 6 );

    // ...
}

The macro expects the following arguments:

• env: environment under which the callback is invoked.
• info: callback data.
• argv: variable name for storing argument values.
• argc: variable name for storing the number of provided arguments.
• nargs: expected number of arguments.

If the number of provided arguments does not equal the expected number of arguments, the macro's generated code raises an exception.

STDLIB_NAPI_ARGV_INDEX2ORDINAL( index )

Macro for converting an index to an ordinal numeral.

STDLIB_NAPI_ARGV_INDEX2ORDINAL( 2 )

The macro expects the following arguments:

• index: argument index value.

The first few ordinal numerals are as follows:

• STDLIB_NAPI_ARGV_INDEX2ORDINAL( 0 ): "First".
• STDLIB_NAPI_ARGV_INDEX2ORDINAL( 1 ): "Second".
• STDLIB_NAPI_ARGV_INDEX2ORDINAL( 2 ): "Third".
• STDLIB_NAPI_ARGV_INDEX2ORDINAL( 3 ): "Fourth".
• STDLIB_NAPI_ARGV_INDEX2ORDINAL( 4 ): "Fifth".
• ...
• STDLIB_NAPI_ARGV_INDEX2ORDINAL( 29 ): "Thirtieth".

This macro can be useful when generating error messages which state which argument is invalid (e.g., "invalid argument. First argument must be a number." ).

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.