In the discussion of max/min classes at the March TC39 meeting, there was support for minimal class syntax, but a couple concerns with max/min classes in particular.
One category of concern is the (intentional) bare-bones nature of max/min. In this case though, I think it has been demonstrated that additional concepts (class properties, privates, prototype properties, etc.) can be added to max/min later, if and when experience shows them to be needed. The other category of concern is that max/min decides the core syntactic use of the valuable 'class' reserved keyword in the language. Max/min chooses to use 'class' for a new kind of block with a nested constructor, instead of as direct extensions of the notion of constructor function. I've raised the class as constructor alternative approach before, and it's something that a few teams I've worked with inside Microsoft have advocated. Since a choice on approach for classes will decide the foundation upon which the class keyword is used in the language going forward, I did a writeup of the alternative syntactic approach at http://wiki.ecmascript.org/doku.php?id=strawman:minimal_classes_as_constructors for comparison. Here's one of the examples from the write-up: class SkinnedMesh(geometry, materials) extends THREE.Mesh(geometry, materials) { // properties on the instance object public identityMatrix = new THREE.Matrix4(); public bones = []; public boneMatrices = []; // ... note, this is the constructor body, statements are allowed here // methods on the prototype object public update(camera) { // ... super.update(); } } Classes as constructors aims to align more closely with existing 'function' syntax, augmenting with the ability to declaratively specify members of the class. Importantly though, methods (and accessors) defined in the class body are bound as prototype properties, not instance properties. This can lead to more succinct classes in many cases, and keeps the notion that a class is primarily a constructor function. Luke _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
