where.js•1.45 kB
var _curry2 = require('./internal/_curry2');
var _has = require('./internal/_has');
/**
* Takes a spec object and a test object; returns true if the test satisfies
* the spec. Each of the spec's own properties must be a predicate function.
* Each predicate is applied to the value of the corresponding property of the
* test object. `where` returns true if all the predicates return true, false
* otherwise.
*
* `where` is well suited to declaratively expressing constraints for other
* functions such as `filter` and `find`.
*
* @func
* @memberOf R
* @since v0.1.1
* @category Object
* @sig {String: (* -> Boolean)} -> {String: *} -> Boolean
* @param {Object} spec
* @param {Object} testObj
* @return {Boolean}
* @example
*
* // pred :: Object -> Boolean
* var pred = R.where({
* a: R.equals('foo'),
* b: R.complement(R.equals('bar')),
* x: R.gt(_, 10),
* y: R.lt(_, 20)
* });
*
* pred({a: 'foo', b: 'xxx', x: 11, y: 19}); //=> true
* pred({a: 'xxx', b: 'xxx', x: 11, y: 19}); //=> false
* pred({a: 'foo', b: 'bar', x: 11, y: 19}); //=> false
* pred({a: 'foo', b: 'xxx', x: 10, y: 19}); //=> false
* pred({a: 'foo', b: 'xxx', x: 11, y: 20}); //=> false
*/
module.exports = _curry2(function where(spec, testObj) {
for (var prop in spec) {
if (_has(prop, spec) && !spec[prop](testObj[prop])) {
return false;
}
}
return true;
});