All files / nary-function/lib main.js

35.91% Statements 65/181
100% Branches 1/1
0% Functions 0/1
35.91% Lines 65/181

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 1821x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x                                                                                                                                                                                                                                         1x 1x 1x 1x 1x  
/**
* @license Apache-2.0
*
* Copyright (c) 2021 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
 
'use strict';
 
// MODULES //
 
var isFunction = require( '@stdlib/assert/is-function' );
var isNonNegativeInteger = require( '@stdlib/assert/is-nonnegative-integer' ).isPrimitive;
var format = require( '@stdlib/string/format' );
 
 
// MAIN //
 
/**
* Returns a function that applies a specified number of arguments to a provided function.
*
* ## Notes
*
* -   The returned function **always** invokes the wrapped function with a specified number of arguments, even when the returned function is provided fewer arguments. The value for the missing arguments is equal to `undefined`.
*
* @param {Function} fcn - input function
* @param {NonNegativeInteger} arity - number of arguments
* @param {*} [thisArg] - function context
* @throws {TypeError} first argument must be a function
* @throws {TypeError} second argument must be a nonnegative integer
* @returns {Function} function wrapper
*
* @example
* function foo() {
*     var s;
*     var i;
*
*     s = 0;
*     for ( i = 0; i < arguments.length; i++ ) {
*         s += arguments[ i ];
*     }
*     return s;
* }
*
* var bar = naryFunction( foo, 2 );
*
* var out = bar( 1, 2, 3, 4, 5, 6 );
* // returns 3
*/
function naryFunction( fcn, arity, thisArg ) {
	var fcns;
	if ( !isFunction( fcn ) ) {
		throw new TypeError( format( 'invalid argument. First argument must be a function. Value: `%s`.', fcn ) );
	}
	if ( !isNonNegativeInteger( arity ) ) {
		throw new TypeError( format( 'invalid argument. Second argument must be a nonnegative integer. Value: `%s`.', arity ) );
	}
	fcns = [ nullary, unary, binary, ternary, quaternary, quinary ];
	return ( arity < fcns.length ) ? fcns[ arity ] : nary;

	/**
	* Invokes a nullary function.
	*
	* @private
	* @param {...*} [args] - arguments
	* @returns {*} return value
	*/
	function nullary() {
		return fcn.call( thisArg );
	}

	/**
	* Invokes a unary function.
	*
	* @private
	* @param {*} x - input value
	* @param {...*} [args] - arguments
	* @returns {*} return value
	*/
	function unary( x ) {
		return fcn.call( thisArg, x );
	}

	/**
	* Invokes a binary function.
	*
	* @private
	* @param {*} x - input value
	* @param {*} y - input value
	* @param {...*} [args] - arguments
	* @returns {*} return value
	*/
	function binary( x, y ) {
		return fcn.call( thisArg, x, y );
	}

	/**
	* Invokes a ternary function.
	*
	* @private
	* @param {*} x - input value
	* @param {*} y - input value
	* @param {*} z - input value
	* @param {...*} [args] - arguments
	* @returns {*} return value
	*/
	function ternary( x, y, z ) {
		return fcn.call( thisArg, x, y, z );
	}

	/**
	* Invokes a quaternary function.
	*
	* @private
	* @param {*} x - input value
	* @param {*} y - input value
	* @param {*} z - input value
	* @param {*} w - input value
	* @param {...*} [args] - arguments
	* @returns {*} return value
	*/
	function quaternary( x, y, z, w ) {
		return fcn.call( thisArg, x, y, z, w );
	}

	/**
	* Invokes a quinary function.
	*
	* @private
	* @param {*} x - input value
	* @param {*} y - input value
	* @param {*} z - input value
	* @param {*} w - input value
	* @param {*} v - input value
	* @param {...*} [args] - arguments
	* @returns {*} return value
	*/
	function quinary( x, y, z, w, v ) {
		return fcn.call( thisArg, x, y, z, w, v );
	}

	/**
	* Invokes an n-ary function.
	*
	* @private
	* @param {*} x - input value
	* @param {*} y - input value
	* @param {*} z - input value
	* @param {*} w - input value
	* @param {*} v - input value
	* @param {*} t - input value
	* @param {...*} args - arguments
	* @returns {*} return value
	*/
	function nary( x, y, z, w, v, t ) {
		var args;
		var i;

		args = [ x, y, z, w, v, t ];
		for ( i = 6; i < arity; i++ ) {
			args.push( arguments[ i ] );
		}
		return fcn.apply( thisArg, args );
	}
}
 
 
// EXPORTS //
 
module.exports = naryFunction;