refactor: improve type inference and update descriptions

Ref: #856
Ref: 0aa7b4a

Author: kgryte

lib/node_modules/@stdlib/string/base/for-each-right/README.md

@@ -20,7 +20,7 @@ limitations under the License.
 
 # forEachRight
 
-> Invokes a function for each UTF-16 code unit in a string iterating from right to left.
+> Invokes a function for each UTF-16 code unit in a string, iterating from right to left.
 
 <!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
 
@@ -42,7 +42,7 @@ var forEachRight = require( '@stdlib/string/base/for-each-right' );
 
 #### forEachRight( str, clbk\[, thisArg ] )
 
-Invokes a function for each UTF-16 code unit in a string iterating from right to left.
+Invokes a function for each UTF-16 code unit in a string, iterating from right to left.
 
 ```javascript
 function log( value, index ) {

lib/node_modules/@stdlib/string/base/for-each-right/docs/types/index.d.ts

@@ -23,15 +23,15 @@
 *
 * @returns result
 */
-type Nullary = () => any;
+type Nullary<T> = ( this: T ) => any;
 
 /**
 * Callback invoked for each UTF-16 code unit in a string.
 *
 * @param value - character
 * @returns result
 */
-type Unary = ( value: string ) => any;
+type Unary<T> = ( this: T, value: string ) => any;
 
 /**
 * Callback invoked for each UTF-16 code unit in a string.
@@ -40,7 +40,7 @@ type Unary = ( value: string ) => any;
 * @param index - character index
 * @returns result
 */
-type Binary = ( value: string, index: number ) => any;
+type Binary<T> = ( this: T, value: string, index: number ) => any;
 
 /**
 * Callback invoked for each UTF-16 code unit in a string.
@@ -50,7 +50,7 @@ type Binary = ( value: string, index: number ) => any;
 * @param str - input string
 * @returns result
 */
-type Ternary = ( value: string, index: number, str: string ) => any;
+type Ternary<T> = ( this: T, value: string, index: number, str: string ) => any;
 
 /**
 * Callback invoked for each UTF-16 code unit in a string.
@@ -60,10 +60,10 @@ type Ternary = ( value: string, index: number, str: string ) => any;
 * @param str - input string
 * @returns result
 */
-type Callback = Nullary | Unary | Binary | Ternary;
+type Callback<T> = Nullary<T> | Unary<T> | Binary<T> | Ternary<T>;
 
 /**
-* Invokes a function for each UTF-16 code unit in a string iterating from right to left.
+* Invokes a function for each UTF-16 code unit in a string, iterating from right to left.
 *
 * ## Notes
 *
@@ -85,7 +85,7 @@ type Callback = Nullary | Unary | Binary | Ternary;
 *
 * forEach( 'Hello, World!', log );
 */
-declare function forEachRight( str: string, clbk: Callback, thisArg?: any ): string;
+declare function forEachRight<T = unknown>( str: string, clbk: Callback<T>, thisArg?: ThisParameterType<Callback<T>> ): string;
 
 
 // EXPORTS //

lib/node_modules/@stdlib/string/base/for-each-right/lib/index.js

@@ -19,7 +19,7 @@
 'use strict';
 
 /**
-* Invoke a function for each UTF-16 code unit in a string iterating from right to left.
+* Invoke a function for each UTF-16 code unit in a string, iterating from right to left.
 *
 * @module @stdlib/string/base/for-each-right
 *

lib/node_modules/@stdlib/string/base/for-each-right/lib/main.js

@@ -21,7 +21,7 @@
 // MAIN //
 
 /**
-* Invokes a function for each UTF-16 code unit in a string iterating from right to left.
+* Invokes a function for each UTF-16 code unit in a string, iterating from right to left.
 *
 * @param {string} str - input string
 * @param {Function} clbk - function to invoke

lib/node_modules/@stdlib/string/base/for-each-right/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@stdlib/string/base/for-each-right",
   "version": "0.0.0",
-  "description": "Invoke a function for each UTF-16 code unit in a string iterating from right to left.",
+  "description": "Invoke a function for each UTF-16 code unit in a string, iterating from right to left.",
   "license": "Apache-2.0",
   "author": {
     "name": "The Stdlib Authors",