refactor: avoid unnecessary concat, fix benchmark, and clean-up

Ref: #1463
Ref: bb7817f

Author: kgryte

lib/node_modules/@stdlib/array/base/join/README.md

@@ -67,6 +67,8 @@ var out = join( x, ',' );
     x.join( separator )
     ```
 
+-   If provided an array-like object without a `join` method, the function manually constructs the output string.
+
 -   If an array element is either `null` or `undefined`, the function will serialize the element as an empty string.
 
 </section>
@@ -99,8 +101,8 @@ s = join( x, ',' );
 s = join( x, '-' );
 // returns '0-1-2-3-4-5'
 
-s = new AccessorArray( [ 1, 2, 3, 4 ] );
-s = join( s, ',' );
+x = new AccessorArray( [ 1, 2, 3, 4 ] );
+s = join( x, ',' );
 // returns '1,2,3,4'
 
 x = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );

lib/node_modules/@stdlib/array/base/join/benchmark/benchmark.length.js

@@ -22,7 +22,7 @@
 
 var bench = require( '@stdlib/bench' );
 var pow = require( '@stdlib/math/base/special/pow' );
-var isString = require( '@stdlib/assert/is-string' );
+var isString = require( '@stdlib/assert/is-string' ).isrPrimitive;
 var ones = require( '@stdlib/array/base/ones' );
 var pkg = require( './../package.json' ).name;
 var join = require( './../lib' );
@@ -58,10 +58,10 @@ function createBenchmark( len ) {
 				b.fail( 'should return a string' );
 			}
 		}
+		b.toc();
 		if ( !isString( s ) ) {
 			b.fail( 'should return a string' );
 		}
-		b.toc();
 		b.pass( 'benchmark finished' );
 		b.end();
 	}

lib/node_modules/@stdlib/array/base/join/docs/repl.txt

@@ -1,11 +1,11 @@
 
 {{alias}}( x, separator )
-    Return a string created by joining array elements using a
-    specified separator.
+    Return a string created by joining array elements using a specified
+    separator.
 
-    If provided an array-like object having a `join` method, the function
-    defers execution to that method and assumes that the method has the
-    following signature:
+    If provided an array-like object having a `join` method, the function defers
+    execution to that method and assumes that the method has the following
+    signature:
 
       x.join( separator )
 
@@ -18,12 +18,12 @@
         Input array.
 
     separator: string
-        Separator to be used.
+        Separator.
 
     Returns
     -------
     out: string
-        Joined string.
+        Output string.
 
     Examples
     --------

lib/node_modules/@stdlib/array/base/join/docs/types/index.d.ts

@@ -20,7 +20,7 @@
 
 /// <reference types="@stdlib/types"/>
 
-import { Collection, TypedArray, ComplexTypedArray } from '@stdlib/types/array';
+import { Collection, AccessorArrayLike } from '@stdlib/types/array';
 
 /**
 * Returns a string created by joining array elements using a specified separator.
@@ -30,43 +30,34 @@ import { Collection, TypedArray, ComplexTypedArray } from '@stdlib/types/array';
 * @returns string
 *
 * @example
-* var Float64Array = require( '@stdlib/array/float64' );
-*
-* var x = new Float64Array( [ 1.0, 2.0, 3.0 ] );
+* var x = [ 1, 2, 3 ];
 *
 * var out = join( x, ',' );
 * // returns '1,2,3'
 *
 * @example
-* var Complex128Array = require( '@stdlib/array/complex128' );
-*
-* var x = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
-*
-* var out = join( x, ',' );
-* // returns '1 + 2i,3 + 4i,5 + 6i'
-*/
-declare function join<T extends TypedArray | ComplexTypedArray>( x: T, separator: string ): string;
-
-/**
-* Returns a string created by joining array elements using a specified separator.
+* var x = [ 1, 2, 3, 4, 5, 6 ];
 *
-* @param x - input array
-* @param separator - separator element
-* @returns string
+* var out = join( x, '-' );
+* // returns '1-2-3-4-5-6'
 *
 * @example
-* var x = [ 1, 2, 3 ];
+* var Float64Array = require( '@stdlib/array/float64' );
+*
+* var x = new Float64Array( [ 1.0, 2.0, 3.0 ] );
 *
 * var out = join( x, ',' );
 * // returns '1,2,3'
 *
 * @example
-* var x = [ 1, 2, 3, 4, 5, 6 ];
+* var Complex128Array = require( '@stdlib/array/complex128' );
 *
-* var out = join( x, '-' );
-* // returns '1-2-3-4-5-6'
+* var x = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
+*
+* var out = join( x, ',' );
+* // returns '1 + 2i,3 + 4i,5 + 6i'
 */
-declare function join<T = unknown>( x: Collection<T>, separator: string ): string;
+declare function join<T = unknown>( x: Collection<T> | AccessorArrayLike<T>, separator: string ): string;
 
 
 // EXPORTS //

lib/node_modules/@stdlib/array/base/join/docs/types/test.ts

@@ -53,6 +53,7 @@ import join = require( './index' );
 {
 	const x = [ 1, 2, 3 ];
 
+	join( x, 5 ); // $ExpectError
 	join( x, true ); // $ExpectError
 	join( x, false ); // $ExpectError
 	join( x, null ); // $ExpectError

lib/node_modules/@stdlib/array/base/join/examples/index.js

@@ -21,18 +21,15 @@
 var Complex128Array = require( '@stdlib/array/complex128' );
 var Complex64Array = require( '@stdlib/array/complex64' );
 var Float64Array = require( '@stdlib/array/float64' );
-var zeroTo = require( '@stdlib/array/base/zero-to' );
 var AccessorArray = require( '@stdlib/array/base/accessor' );
 var join = require( './../lib' );
 
 var x = [ 0, 1, 2, 3, 4, 5 ];
-
 var s = join( x, ',' );
 console.log( s );
 // => '0,1,2,3,4,5'
 
-x = new Float64Array( zeroTo( 6 ) );
-
+x = new Float64Array( [ 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 ] );
 s = join( x, ',' );
 console.log( s );
 // => '0,1,2,3,4,5'
@@ -41,20 +38,17 @@ s = join( x, '-' );
 console.log( s );
 // => '0-1-2-3-4-5'
 
-s = new AccessorArray( [ 1, 2, 3, 4 ] );
-
-s = join( s, ',' );
+x = new AccessorArray( [ 1, 2, 3, 4 ] );
+s = join( x, ',' );
 console.log( s );
 // => '1,2,3,4'
 
 x = new Complex128Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
-
 s = join( x, ',' );
 console.log( s );
 // => '1 + 2i,3 + 4i,5 + 6i'
 
 x = new Complex64Array( [ 1.0, -1.0, 2.0, -2.0 ] );
-
 s = join( x, ',' );
 console.log( s );
 // => '1 - 1i,2 - 2i'

lib/node_modules/@stdlib/array/base/join/lib/main.js

@@ -21,6 +21,7 @@
 // MODULES //
 
 var arraylike2object = require( '@stdlib/array/base/arraylike2object' );
+var isUndefinedOrNull = require( '@stdlib/assert/is-undefined-or-null' );
 
 
 // FUNCTIONS //
@@ -46,12 +47,12 @@ function hasMethod( obj, method ) {
 }
 
 /**
-* Returns a string created by joining array elements using a specified separator when input is an accessor array.
+* Returns a string created by joining elements in an accessor array using a specified separator.
 *
 * @private
 * @param {Object} x - input array object
 * @param {integer} separator - separator
-* @returns {string} joined string
+* @returns {string} output string
 *
 * @example
 * var toAccessorArray = require( '@stdlib/array/base/to-accessor-array' );
@@ -63,25 +64,28 @@ function hasMethod( obj, method ) {
 * // returns '1,2,3,4'
 */
 function accessors( x, separator ) {
-	var output;
 	var data;
+	var out;
 	var get;
-	var i;
+	var N;
 	var v;
+	var i;
+
 	data = x.data;
 	get = x.accessors[ 0 ];
-	output = '';
-	for ( i = 0; i < data.length; i++ ) {
+
+	N = data.length - 1;
+	out = '';
+	for ( i = 0; i <= N; i++ ) {
 		v = get( data, i );
-		if ( typeof v === 'undefined' || v === null ) {
-			v = '';
+		if ( !isUndefinedOrNull( v ) ) {
+			out += String( v );
 		}
-		output += v;
-		if ( i < data.length - 1 ) {
-			output += separator;
+		if ( i < N ) {
+			out += separator;
 		}
 	}
-	return output;
+	return out;
 }
 
 /**
@@ -90,29 +94,32 @@ function accessors( x, separator ) {
 * @private
 * @param {Object} x - input array object
 * @param {integer} separator - separator
-* @returns {string} joined string
+* @returns {string} output string
 *
 * @example
 * var x = [ 1, 2, 3, 4 ];
-* var out = constructString( x, ',' );
+*
+* var out = indexed( x, ',' );
 * // returns '1,2,3,4'
 */
-function constructString( x, separator ) {
-	var i;
-	var s;
+function indexed( x, separator ) {
+	var out;
+	var N;
 	var v;
-	s = '';
-	for ( i = 0; i < x.length; i++ ) {
+	var i;
+
+	N = x.length - 1;
+	out = '';
+	for ( i = 0; i <= N; i++ ) {
 		v = x[ i ];
-		if ( typeof v === 'undefined' || v === null ) {
-			v = '';
+		if ( !isUndefinedOrNull( v ) ) {
+			out += String( v );
 		}
-		s += v;
-		if ( i < x.length - 1 ) {
-			s += separator;
+		if ( i < N ) {
+			out += separator;
 		}
 	}
-	return s;
+	return out;
 }
 
 
@@ -122,8 +129,8 @@ function constructString( x, separator ) {
 * Returns a string created by joining array elements using a specified separator.
 *
 * @param {Collection} x - input array
-* @param {integer} separator - separator to be used in string
-* @returns {string} joined string
+* @param {integer} separator - separator
+* @returns {string} output string
 *
 * @example
 * var x = [ 1, 2, 3, 4 ];
@@ -132,7 +139,7 @@ function constructString( x, separator ) {
 * // returns '1,2,3,4'
 *
 * @example
-* var x = [ 1, 2, 3, null, undefined,  4 ];
+* var x = [ 1, 2, 3, null, undefined, 4 ];
 *
 * var out = join( x, '-' );
 * // returns '1-2-3---4'
@@ -146,10 +153,7 @@ function join( x, separator ) {
 	if ( obj.accessorProtocol ) {
 		return accessors( obj, separator );
 	}
-	if ( obj.dtype === 'generic' || obj.dtype === null ) {
-		return constructString( x, separator );
-	}
-	return x.join( separator );
+	return indexed( x, separator );
 }