class: захват и сохранение this
 

Это - работает:

var ClassWithId = (function() {
    function ClassWithId(id) {
        this.id = id;
    }
    return ClassWithId;
}());

var ClassWithClosures = (function() {
    var me;

    function ClassWithClosures(id) {
        me = this;
        this.id = id;
    }

    ClassWithClosures.prototype.isMatch = function(num) {
        return (function(_num) {
            return !!me.id.id && _num % 2 === 0;
        })(num);
    };
    return ClassWithClosures;
}());

var arrayOfInt = [1, 2, 3, 4, 5, 6, 7, 8, 9];
var classWithClosure = new ClassWithClosures(new ClassWithId("blah"));
var resultOfFilter = arrayOfInt.filter(classWithClosure.isMatch);
for (var i = 0, l = resultOfFilter.length; i < l; i++) {
    if (window.console && console.log) {
        console.log(resultOfFilter[i]);
    }
}

Как заставить работать это:

class ClassWithClosuresNewStyle {
	var me; !!! error "Uncaught SyntaxError: unexpected token: identifier"

	constructor(id) {
		this.id = id;
	}
	
	isMatch(num) {
	    return(function(_num) {
		  return !!me.id.id && _num %2 === 0;
		})(num);
	}
}

var arrayOfInt = [1, 2, 3, 4, 5, 6, 7, 8, 9];
var classWithClosureNewStyle = new ClassWithClosuresNewStyle(new ClassWithId("blah"));
var resultOfFilter = arrayOfInt.filter(classWithClosureNewStyle.isMatch);
for (var i = 0, l = resultOfFilter.length; i < l; i++) {
    if (window.console && console.log) {
        console.log(resultOfFilter[i]);
    }
}

???

Ну... И... Первоисточник, така сказать, на TypeScript

class ClassWithId {
    constructor(public id?: string) {
    }
}

class ClassWithClosures {
    constructor(public id?: ClassWithId) {
    }

    public isMatch(num: number): boolean {
        const tmpId = this.id;

        return ((_id: ClassWithId, _num: number) => {
            return !!_id.id && _num % 2 === 0;
        })(tmpId, num);
    }
}

let arrayOfInt = [1, 2, 3, 4, 5, 6, 7, 8, 9];
let classWithClosure = new ClassWithClosures();
let resultOfFilter = arrayOfInt.filter(classWithClosure.isMatch);
for (let i = 0, l = resultOfFilter.length; i < l; i++) {
    if (window.console && console.log) {
        console.log(resultOfFilter[i]);
    }
}

???

Всем спасибо - заборол:

class ClassWithClosuresNewStyle {
	constructor(id) {
		this.id = id;
	}
	
	isMatch = (num) => {
		return !!this.id.id && num %2 === 0;
	}
}