After removing optional initializing formal parameters from the VM
yesterday, the language team decided that they should be allowed
and made usable.
- The name of an optional initializing formal is the name of
the field it initializes.
- The parameter is only visible at the call site of the constructor,
to name the parameter.
- The parameter is NOT visible in the constructor's initializer list
and body.
class A {
A([this.x = 10]);
A.bad([this.x = 10]) : y = x; // Error: parameter x not in scope
A.ok([this.x = 10]) { print(x); } // Refers to field x, not parameter x.
var x, y;
}
o = new A(x: 50); // o.x == 50.
o = new A(); // o.x == 10.
Review URL: http://codereview.chromium.org//8682025
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@1819 260f80e4-7a28-3924-810f-c04153c831b5
hausner@google.com
0ef3609ec0