argv_strided_float32array

Usage

#include "stdlib/napi/argv_strided_float32array.h"

stdlib_napi_argv_strided_float32array( env, N, stride, value, **data, *message1, *message2, *err )

Converts a Node-API value representing a strided array to a single-precision floating-point array.

#include "stdlib/napi/argv_strided_float32array.h"
#include <node_api.h>
#include <stdint.h>

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

    // ...

    int64_t N = 100;
    int64_t stride = 1;

    // ...

    float *X;
    napi_value err;
    napi_status status = stdlib_napi_argv_strided_float32array( env, N, stride, value, &X, "Must be a typed array.", "Must have sufficient elements.", &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.
• N: [in] int64_t number of indexed elements.
• stride: [in] int64_t stride length.
• value: [in] napi_value Node-API value.
• data: [out] float** pointer for returning a reference to the output array.
• message1: [in] char* error message if a value is not a Float32Array.
• message2: [in] char* error message if a value has insufficient elements.
• 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_strided_float32array( const napi_env env, const int64_t N, const int64_t stride, const napi_value value, float **data, const char *message1, const char *message2, napi_value *err );

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

STDLIB_NAPI_ARGV_STRIDED_FLOAT32ARRAY( env, X, N, stride, argv, index )

Macro for converting an add-on callback argument to a strided single-precision floating-point array.

#include "stdlib/napi/argv_strided_float32array.h"
#include "stdlib/napi_argv_int64.h"
#include "stdlib/napi/argv.h"
#include <node_api.h>
#include <stdint.h>

static void fcn( const int64_t N, const float *X, const int64_t strideX, float *Y, const int64_t strideY ) {
    int64_t i;
    for ( i = 0; i < N; i++ ) {
        Y[ i*strideY ] = X[ i*strideX ];
    }
}

// ...

static napi_value addon( napi_env env, napi_callback_info info ) {
    // Retrieve add-on callback arguments:
    STDLIB_NAPI_ARGV( env, info, argv, argc, 5 );

    // Convert the number of indexed elements to a C type:
    STDLIB_NAPI_ARGV_INT64( env, N, argv, 0 );

    // Convert the stride arguments to C types:
    STDLIB_NAPI_ARGV_INT64( env, strideX, argv, 2 );
    STDLIB_NAPI_ARGV_INT64( env, strideY, argv, 4 );

    // Convert the arrays a C types:
    STDLIB_NAPI_ARGV_STRIDED_FLOAT32ARRAY( env, X, N, strideX, argv, 1 );
    STDLIB_NAPI_ARGV_STRIDED_FLOAT32ARRAY( env, Y, N, strideY, argv, 3 );

    // ...

    fcn( N, X, strideX, Y, strideY );
}

The macro expects the following arguments:

• env: environment under which the callback is invoked.
• X: output variable name for the array.
• N: number of indexed elements.
• stride: stride length.
• argv: name of the variable containing add-on callback arguments.
• index: argument index.