ecman/function-at

# function-at

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Pass functions with adjusted arguments

# Usage

```js
require('function-at');

function thenable(name) {
  if (!name) return Promise.reject(
    new TypeError('name string required'));
  var greeting = 'Hello, ' + name + '!';
  return Promise.resolve(greeting);
}

// Normal callback
function callback(error, result) {
  console.log('calback ---------------');
  console.log('  error:', error);
  console.log('  result:', result);
}

thenable('Friday')
  // On fulfillment 
  // set error to null
  .then(callback.atfirst(null))
```

Output:

```text
calback ---------------
  error: null
  result: Hello, Friday!
```

Catch example:

```js
// Given the thenable() and callback()
// functions definitions...

thenable() 
  // On rejection 
  // set result to empty string
  .catch(callback.atlast(''));
```

Catch output:

```text
calback ---------------
  error: [TypeError: name string required]
  result: 
```