Implement class fields. Restrict assigning new fields to an instance. Fields must be defined on the class to access or write to.

Example

class Parent {
  let a = 123;
  let b = 456;
}

class Child extends Parent {
  let b = 789;
}

let parent = Parent();
print parent.a; // out: 123
print parent.b // out: 456

let child = Child();
print child.a; // out: 123
print child.b; // out: 789

print parent.c; // out: NameError: name "c" isn't defined on class "Parent"
parent.c = 1000; // out: NameError: name "c" isn't defined on class "Parent"

Requirements

Fields are a superset of assignment statements e.g. let prefix, optional initialization with value let value = default;
Field names must not conflict with method names
Fields are inherited
Fields can be initialized by creating a constructor/init method

kyleect / locks

Class fields #84

Example

Requirements