7  * @param { any } value
10 function callable(value) {  argument
11   return typeof value === 'function';
17  * @param { any } value
20 function defined(value) {  argument
21   return value !== undefined;
39  * @param { any } value
42 function escaped(value) {  argument
43   return value instanceof SafeString;
62  * Returns `true` if the value is evenly divisible by 2.
63  * @param { number } value
66 function even(value) {  argument
67   return value % 2 === 0;
72  * Returns `true` if the value is falsy - if I recall correctly, '', 0, false,
76  * @param { any } value
79 function falsy(value) {  argument
80   return !value;
140  * @param { string } value
143 function lower(value) {  argument
144   return value.toLowerCase() === value;
161  * Returns true if the value is strictly equal to `null`.
165 function nullTest(value) {  argument
166   return value === null;
171  * Returns true if value is a number.
175 function number(value) {  argument
176   return typeof value === 'number';
181  * Returns `true` if the value is *not* evenly divisible by 2.
182  * @param { number } value
185 function odd(value) {  argument
186   return value % 2 === 1;
191  * Returns `true` if the value is a string, `false` if not.
192  * @param { any } value
195 function string(value) {  argument
196   return typeof value === 'string';
201  * Returns `true` if the value is not in the list of things considered falsy:
203  * @param { any } value
206 function truthy(value) {  argument
207   return !!value;
212  * Returns `true` if the value is undefined.
213  * @param { any } value
216 function undefinedTest(value) {  argument
217   return value === undefined;
223  * @param { string } value
226 function upper(value) {  argument
227   return value.toUpperCase() === value;
232  * If ES6 features are available, returns `true` if the value implements the
238  * @param { any } value
241 function iterable(value) {  argument
243     return !!value[Symbol.iterator];
245     return Array.isArray(value) || typeof value === 'string';
251  * If ES6 features are available, returns `true` if the value is an object hash
253  * @param { any } value
256 function mapping(value) {  argument
258 …var bool = value !== null && value !== undefined && typeof value === 'object' && !Array.isArray(va…
260     return bool && !(value instanceof Set);