@stdlib/strided-napi-addon-arguments NPM

Add-on Arguments

C API for validating, extracting, and transforming (to native C types) function arguments provided to a strided array Node-API add-on interface.

Installation

npm install @stdlib/strided-napi-addon-arguments

Usage

var headerDir = require( '@stdlib/strided-napi-addon-arguments' );

headerDir

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

var dir = headerDir;
// returns <string>

Examples

var headerDir = require( '@stdlib/strided-napi-addon-arguments' );

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

C APIs

Usage

#include "stdlib/strided/napi/addon_arguments.h"

stdlib_strided_napi_addon_arguments( env, argv, nargs, nin, arrays[], shape, strides, types, *err )

Validates, extracts, and transforms (to native C types) function arguments provided to a strided array Node-API add-on interface.

#include <node_api.h>
#include <stdint.h>
#include <assert.h>

// ...

/**
* Receives JavaScript callback invocation data.
*
* @param env    environment under which the function is invoked
* @param info   callback data
* @return       Node-API value
*/
napi_value addon( napi_env env, napi_callback_info info ) {
    napi_status status;

    // ...

    int64_t nargs = 10;
    int64_t nin = 2;

    // Get callback arguments:
    size_t argc = 10;
    napi_value argv[ 10 ];
    status = napi_get_cb_info( env, info, &argc, argv, NULL, NULL );
    assert( status == napi_ok );

    // ...

    // Initialize destination arrays:
    uint8_t *arrays[ 3 ];
    int64_t strides[ 3 ];
    int64_t shape[ 1 ];
    int32_t types[ 3 ];

    // Process the provided arguments:
    napi_value err;
    status = stdlib_strided_napi_addon_arguments( env, argv, nargs, nin, arrays, shape, strides, types, &err );
    assert( status == napi_ok );

    // ...

}

// ...

The function accepts the following arguments:

env: [in] napi_env environment under which the function is invoked.
argv: [in] napi_value* strided function arguments.
nargs: [in] int64_t total number of expected arguments.
nin: [in] int64_t number of input strided array arguments.
arrays: [out] uint8_t** destination array for storing pointers to both input and output strided byte arrays.
shape: [out] int64_t* destination array for storing the array shape (dimensions).
strides: [out] int64_t* destination array for storing array strides (in bytes) for each strided array.
types: [out] int32_t* destination array for storing strided array argument data types.
err: [out] napi_value* pointer for storing a JavaScript error.

napi_status stdlib_strided_napi_addon_arguments( const napi_env env, const napi_value *argv, const int64_t nargs, const int64_t nin, uint8_t *arrays[], int64_t *shape, int64_t *strides, int32_t *types, napi_value *err );

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

Notes

The function assumes the following argument order:
```
[ N, id1, ia1, is1, id2, ia2, is2, ..., od1, oa1, os1, od2, oa2, os2, ... ]
```
where
- N is the number of elements over which to iterate.
- id# is an input strided array data type (enumeration constant).
- ia# is an input strided array.
- is# is a corresponding input strided array stride (in units of elements).
- od# is an output strided array data type (enumeration constant).
- oa# is an output strided array.
- os# is a corresponding output strided array stride (in units of elements).
The function may return one of the following JavaScript errors:
- TypeError: first argument must be an integer.
- TypeError: input array data type argument must be an integer.
- TypeError: output array data type argument must be an integer.
- TypeError: input array stride argument must be an integer.
- TypeError: output array stride argument must be an integer.
- TypeError: input array argument must be a typed array.
- TypeError: output array argument must be a typed array.
- RangeError: input array argument must have sufficient elements based on the associated stride and the number of indexed elements.
- RangeError: output array argument must have sufficient elements based on the associated stride and the number of indexed elements.

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.