dart2js: Type assertions and casts fail for Polymer code

[rakudrama]

This problem is blocking polymer integration with web components.

class Observable {}
class ObservableMixin implements Observable {}
class HtmlElement native ... {}
class PolymerElement extends HtmlElement with ObservableMixin {}

This check fails:

    p = ... // a PolymerElement
    ...
    Observable o = p;

The way to fix this is to fix Issue #9732 - all type checking code takes an interceptor with the argument, and the optimizer can specialize or remove the interceptor where appropriate.

[kasperl]

Added Triaged label.

[kasperl]

Are you looking into fixing this, Stephen?

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Set owner to @rakudrama.

[rakudrama]

r28471 is a work-around by always forcing the interceptor variant.

What really needs to happen is to pass the interceptor for the tested argument in to all the checked mode and cast helpers so that getInterceptor happens at most once.
I believe we already did this for HIs instructions.

[kasperl]

So for now, this issue isn't blocking. Lowering priority.

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Removed Priority-Critical label.
Added Priority-High label.

[rakudrama]

Kasper: This issue is blocked on Issue #9732 but that is marked Priority-Medium Milestone-Later.
Do you think someone (Johnni / Karl / Nicolas) should fix 9732 for M8 or this issue should be downgraded a little?

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cc @kasperl.

[DartBot]

This comment was originally written by [email protected]

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Passing getInterceptor to the helpers is an optimization we don't need to 'fix' the workaround. After talking to Johnni and Karl, we can fix the workaround by checking if a type is implemented by a native type.

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Unmarked this as being blocked by #9732.

[kasperl]

Removed this from the M8 milestone.
Added this to the 1.6 milestone.

[rakudrama]

The type assertions have been worked-around.

I don't plan to do the optimization of hoisting the getInterceptor call.
I believe the best way forward with this is to replace all types with (cached, hash-consed) instances of RuntimeType https://code.google.com/p/dart/source/browse/branches/bleeding_edge/dart/sdk/lib/_internal/lib/js_helper.dart?spec=svn30932&r=30932#­2038

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Added NotPlanned label.