time-to-botec/squiggle/node_modules/@stdlib/math/base/napi/unary/README.md

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# unary

> C APIs for registering a Node-API module exporting interfaces for invoking unary numerical functions.

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## Usage

```javascript
var headerDir = require( '@stdlib/math/base/napi/unary' );
```

#### headerDir

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

```javascript
var dir = headerDir;
// returns <string>
```

</section>

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## Examples

```javascript
var headerDir = require( '@stdlib/math/base/napi/unary' );

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

</section>

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* * *

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## C APIs

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### Usage

```c
#include "stdlib/math/base/napi/unary.h"
```

#### stdlib_math_base_napi_d_d( env, info, fcn )

Invokes a unary function accepting and returning double-precision floating-point numbers.

```c
#include <node_api.h>

// ...

static double identity( const double x ) {
    return x;
}

// ...

/**
* 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 ) {
    return stdlib_math_base_napi_d_d( env, info, identity );
}

// ...
```

The function accepts the following arguments:

-   **env**: `[in] napi_env` environment under which the function is invoked.
-   **info**: `[in] napi_callback_info` callback data.
-   **fcn**: `[in] double (*fcn)( double )` unary function.

```c
void stdlib_math_base_napi_d_d( napi_env env, napi_callback_info info, double (*fcn)( double ) );
```

#### stdlib_math_base_napi_f_f( env, info, fcn )

Invokes a unary function accepting and returning single-precision floating-point numbers.

```c
#include <node_api.h>

// ...

static float identityf( const float x ) {
    return x;
}

// ...

/**
* 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 ) {
    return stdlib_math_base_napi_f_f( env, info, identityf );
}

// ...
```

The function accepts the following arguments:

-   **env**: `[in] napi_env` environment under which the function is invoked.
-   **info**: `[in] napi_callback_info` callback data.
-   **fcn**: `[in] float (*fcn)( float )` unary function.

```c
void stdlib_math_base_napi_f_f( napi_env env, napi_callback_info info, float (*fcn)( float ) );
```

#### stdlib_math_base_napi_i_i( env, info, fcn )

Invokes a unary function accepting and returning 32-bit signed integers.

```c
#include <node_api.h>
#include <stdint.h>

// ...

static int32_t identity( const int32_t x ) {
    return x;
}

// ...

/**
* 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 ) {
    return stdlib_math_base_napi_i_i( env, info, identity );
}

// ...
```

The function accepts the following arguments:

-   **env**: `[in] napi_env` environment under which the function is invoked.
-   **info**: `[in] napi_callback_info` callback data.
-   **fcn**: `[in] int32_t (*fcn)( int32_t )` unary function.

```c
void stdlib_math_base_napi_i_i( napi_env env, napi_callback_info info, int32_t (*fcn)( int32_t ) );
```

#### STDLIB_MATH_BASE_NAPI_MODULE_D_D( fcn )

Macro for registering a Node-API module exporting an interface for invoking a unary function accepting and returning double-precision floating-point numbers.

```c
static double scale( const double x ) {
    return x * 10.0;
}

// ...

// Register a Node-API module:
STDLIB_MATH_BASE_NAPI_MODULE_D_D( scale );
```

The macro expects the following arguments:

-   **fcn**: `double (*fcn)( double )` unary function.

When used, this macro should be used **instead of** `NAPI_MODULE`. The macro includes `NAPI_MODULE`, thus ensuring Node-API module registration.

#### STDLIB_MATH_BASE_NAPI_MODULE_F_F( fcn )

Macro for registering a Node-API module exporting an interface for invoking a unary function accepting and returning single-precision floating-point numbers.

```c
static float scale( const float x ) {
    return x * 10.0f;
}

// ...

// Register a Node-API module:
STDLIB_MATH_BASE_NAPI_MODULE_F_F( scale );
```

The macro expects the following arguments:

-   **fcn**: `float (*fcn)( float )` unary function.

When used, this macro should be used **instead of** `NAPI_MODULE`. The macro includes `NAPI_MODULE`, thus ensuring Node-API module registration.

#### STDLIB_MATH_BASE_NAPI_MODULE_I_I( fcn )

Macro for registering a Node-API module exporting an interface for invoking a unary function accepting and returning 32-bit signed integers.

```c
#include <stdint.h>

static int32_t scale( const int32_t x ) {
    return x * 10;
}

// ...

// Register a Node-API module:
STDLIB_MATH_BASE_NAPI_MODULE_I_I( scale );
```

The macro expects the following arguments:

-   **fcn**: `int32_t (*fcn)( int32_t )` unary function.

When used, this macro should be used **instead of** `NAPI_MODULE`. The macro includes `NAPI_MODULE`, thus ensuring Node-API module registration.

</section>

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### Notes

-   The C-API functions expect that the callback `info` argument provides access to the following JavaScript arguments:

    -   `x`: input value.

</section>

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</section>

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</section>

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