@stdlib/utils/filter-arguments/README.md

Standard utilities.

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# filterArguments

> Create a function that invokes a provided function according to a predicate function.

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## Usage

```javascript
var filterArguments = require( '@stdlib/utils/filter-arguments' );
```

#### filterArguments( fcn, predicate\[, thisArg] )

Returns a `function` that invokes a provided function according to a `predicate` function.

```javascript
function foo( a, b ) {
    return [ a, b ];
}

function predicate( v ) {
    return ( v !== 2 );
}

var bar = filterArguments( foo, predicate );

var out = bar( 1, 2, 3 );
// returns [ 1, 3 ]
```

The `predicate` function is provided the following arguments:

-   **value**: argument value.
-   **index**: argument index.

To set the `this` context when invoking the input function, provide a `thisArg`.

<!-- eslint-disable no-restricted-syntax -->

```javascript
function predicate( v ) {
    return ( v !== 2 );
}

function Foo() {
    this.x = 1;
    this.y = 2;
}

Foo.prototype.scale = function scale( a, b ) {
    return [ this.x*a, this.y*b ];
};

var ctx = {
    'x': 10,
    'y': 20
};

var foo = new Foo();

var bar = filterArguments( foo.scale, predicate, ctx );

var out = bar( 1, 2, 3 );
// returns [ 10, 60 ]
```

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## Notes

-   Only those arguments in which the `predicate` function returns a truthy value are applied to a provided function.

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## Examples

<!-- eslint no-undef: "error" -->

```javascript
var filledarrayBy = require( '@stdlib/array/filled-by' );
var add = require( '@stdlib/math/base/ops/add' );
var filterArguments = require( '@stdlib/utils/filter-arguments' );

function fill( i ) {
    return i;
}

function factory( i, j ) {
    return predicate;

    function predicate( value, index ) {
        return ( i <= index ) && ( index < j );
    }
}

// Create a data array:
var x = filledarrayBy( 10, 'float64', fill );

// Compute the sum of consecutive elements...
var f;
var i;
for ( i = 0; i < x.length-1; i++ ) {
    f = filterArguments( add, factory( i, i+2 ) );
    console.log( 'sum(x_%d, x_%d) = %d', i, i+1, f.apply( null, x ) );
}
```

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* * *

## See Also

-   <span class="package-name">[`@stdlib/utils/mask-arguments`][@stdlib/utils/mask-arguments]</span><span class="delimiter">: </span><span class="description">create a function that invokes a provided function according to an argument mask.</span>
-   <span class="package-name">[`@stdlib/utils/reject-arguments`][@stdlib/utils/reject-arguments]</span><span class="delimiter">: </span><span class="description">create a function that invokes a provided function according to a predicate function.</span>
-   <span class="package-name">[`@stdlib/utils/reorder-arguments`][@stdlib/utils/reorder-arguments]</span><span class="delimiter">: </span><span class="description">create a function that invokes a provided function with reordered arguments.</span>
-   <span class="package-name">[`@stdlib/utils/reverse-arguments`][@stdlib/utils/reverse-arguments]</span><span class="delimiter">: </span><span class="description">create a function that invokes a provided function with arguments in reverse order.</span>

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[@stdlib/utils/mask-arguments]: https://github.com/stdlib-js/utils/tree/main/mask-arguments

[@stdlib/utils/reject-arguments]: https://github.com/stdlib-js/utils/tree/main/reject-arguments

[@stdlib/utils/reorder-arguments]: https://github.com/stdlib-js/utils/tree/main/reorder-arguments

[@stdlib/utils/reverse-arguments]: https://github.com/stdlib-js/utils/tree/main/reverse-arguments

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