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Yes, this is true. My point is Self's influence lives on. Also, Self's JIT was very influential and was the forerunner to Java JIT research. Copying and modify

by fzzzy 7y ago

Yes, this is true. My point is Self's influence lives on. Also, Self's JIT was very influential and was the forerunner to Java JIT research. Copying and modifying the blueprint always did make way more sense. To this day I still don't think I understand exactly how JavaScript's prototypes work, exactly.

masklinn 7y ago
Javascript's "prototype" is really Self's "trait". Self prototypes have been replaced by constructors which rather than be normal instances are special constructs building instances then setting their prototype property as the (sole) parent to the new instance. You can partially replicate Self's mechanism by performing a regular shallow-copy (e.g. using `Object.assign(target, source)` then explicitly copying over the prototype (that's fallible as Object.assign only copies the values of enumerable own properties so it's not going to copy the properties themselves).
ChrisSD 7y ago
To expand on masklinn's point, Javascript's prototypes are actually very simple. It's just people overcomplicated it so as to do things it wasn't designed for (e.g. emulate Java classes). These points covers most of what a prototype is: 1. A prototype is simply another object (or null). 2. Every object can have one (and only one) prototype. 3. When looking up a property that doesn't exist on the object, the object will delegate to its prototype. 4. When calling a function on an object, the `this` keyword will be bound to that object, even if the function is defined in the object's prototype. A simple example to explain what I mean: // Provide a default implementation of a kitten const kitten = { name: "unnamed :(", greet() { // Note that `this` will be bound to // the object that invoked the method console.log(`Meow! I'm ${this.name}.`); } } // Create a named kitten. // `Object.create` creates a new object and sets // its prototype. const grabbity = Object.create(kitten); grabbity.name = "Grabbity"; // Call `greet` on the kittens. kitten.greet(); // outputs "Meow! I'm unnamed :(." grabbity.greet(); // outputs "Meow! I'm Grabbity." The only other thing to mention is something you can probably infer: Every prototype is an object therefore a prototype can have its own prototype (and so on). In this way prototypes can be chained.

by fzzzy 7y ago

masklinn 7y ago

Javascript's "prototype" is really Self's "trait". Self prototypes have been replaced by constructors which rather than be normal instances are special constructs building instances then setting their prototype property as the (sole) parent to the new instance. You can partially replicate Self's mechanism by performing a regular shallow-copy (e.g. using `Object.assign(target, source)` then explicitly copying over the prototype (that's fallible as Object.assign only copies the values of enumerable own properties so it's not going to copy the properties themselves).

ChrisSD 7y ago

To expand on masklinn's point, Javascript's prototypes are actually very simple. It's just people overcomplicated it so as to do things it wasn't designed for (e.g. emulate Java classes). These points covers most of what a prototype is: 1. A prototype is simply another object (or null). 2. Every object can have one (and only one) prototype. 3. When looking up a property that doesn't exist on the object, the object will delegate to its prototype. 4. When calling a function on an object, the `this` keyword will be bound to that object, even if the function is defined in the object's prototype. A simple example to explain what I mean: // Provide a default implementation of a kitten const kitten = { name: "unnamed :(", greet() { // Note that `this` will be bound to // the object that invoked the method console.log(`Meow! I'm ${this.name}.`); } } // Create a named kitten. // `Object.create` creates a new object and sets // its prototype. const grabbity = Object.create(kitten); grabbity.name = "Grabbity"; // Call `greet` on the kittens. kitten.greet(); // outputs "Meow! I'm unnamed :(." grabbity.greet(); // outputs "Meow! I'm Grabbity." The only other thing to mention is something you can probably infer: Every prototype is an object therefore a prototype can have its own prototype (and so on). In this way prototypes can be chained.