Version 2.x

While instanceof operator works only for linear prototypal inheritance, dcl.isInstanceOf() is its counterpart for mixins.

Description

JavaScript provides instanceof operator to check if an object was produced with a certain constructor or its delegate. Unfortunately this functionality works only for a linear delegation. Mixins are by necessity mixed in, so they cannot be detected by instanceof. This functionality is provided by dcl.isInstanceOf() function, which takes the object and the constructor as parameters, and returns true, when the object contains the supplied mixin or base constructor, and false otherwise.

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var A = dcl(null, {});
var B = dcl(null, {});
var C = dcl(null, {});
var D = dcl(null, {});

var ABC = dcl([A, B, C], {});
var abc = new ABC();

console.log(abc instanceof A); // true
console.log(abc instanceof B); // false
console.log(abc instanceof C); // false
console.log(abc instanceof D); // false

console.log(dcl.isInstanceof(abc, A)); // true
console.log(dcl.isInstanceof(abc, B)); // true
console.log(dcl.isInstanceof(abc, C)); // true
console.log(dcl.isInstanceof(abc, D)); // false

Notes

This function has a linear complexity on a number of mixins.