can't refer to constructor parameters passed using this.x syntax.

[trinarytree]

to reproduce:
1 class A {
2 A(x) {}
3 }
4 class B extends A {
5 var _x;
6 B(this._x) : super(_x);
7 }
8 main() {
9 new B(1);
10 }

this yields
'error: line 6 pos 22: illegal implicit access to receiver 'this'
  B(this._x) : super(_x);

on line 6, apparently _x refers to the instance variable, instead of to the constructor parameter.
maybe it would make more sense for _x used as an r-value inside a constructor initializer to refer to the
constructor parameter and _x used as an l-value to refer to the instance variable. e.g.
B(x) : x = 1; // assign 1 to the instance var x
B(x) : y = x; // assign the passed in x to the instance var y

Dart VM version: 1.0.1.1_r30601 (Fri Nov 22 17:38:17 2013) on "linux_x64"

[iposva-google]

Added Area-Language, Triaged labels.