equality.js

// Equality
// equal :: a -> b -> boolean
function equal (a, b) {
    if (typeof a !== typeof b) {
        return false;
    }
    if (a === b) {
        return true;
    }
    if (Array.isArray(a) && Array.isArray(b)) {
        if (a.length !== b.length) {
            return false;
        }
        for (var i in a) {
            if (!equal(a[i], b[i])) {
                return false;
            }
        }
        return true;
    }
    if (Array.isArray(a) === !Array.isArray(b)) {
        return false;
    }
    if (typeof a === 'object') {
        for (var key in a) {
            if (!equal(a[key], b[key])) {
                return false;
            }
        }
        return true;
    }
    return false;
}

// Curried equality
// equals :: a -> (b -> boolean)
function equals (a) {
    return function (b) {
        return equal(a, b);
    };
}