Jexl - Javascript Expression Language: Powerful context-based expression parser and evaluator

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Jexl requires an environment that supports the Promise/A+ specification as standardized in ES6. Node.js version 0.12.0 and up is great right out of the box (no --harmony flag necessary), as well as the latest versions of many browsers. To support older browsers, just include a Promise library such as Bluebird. The in operator can be used to check for a substring: "Cad" in "Ron Cadillac", and it can be used to check for an array element: "coarse" in ['fine', 'medium', 'coarse']. However, the == operator is used behind-the-scenes to search arrays, so it should not be used with arrays of objects. The following expression returns false: {a: 'b'} in [{a: 'b'}].



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