Parser rejects some uses of inner constraints

[jruderman]

tag ordered_pair_list {
    cons({low: int, high: int} : lt(*.low, *.high), @ordered_pair_list);
    nil;
}
pure fn lt(x: int, y: int) -> bool { ret x < y; }
fn main() { }

Gives me

tmp.rs:2:52: 2:53 error: expecting (, found @
tmp.rs:2     cons({low: int, high: int} : lt(*.low, *.high), @ordered_pair_list);

But if I take out the ", @ordered_pair_list" part, the parser accepts it (and I hit #970 instead).

Are inner constraints valid?

[catamorphism]

This isn't implemented yet, but it should be implemented at some point.

[nikomatsakis]

Not relevant as of commit 41a21f0, which removed current incarnation of typestate.