Inferring lambda parameter types in an argument position

[Neal Gafter]

Dear Lambda-

I'd like the lambda conversion to infer lambda parameter types even when the
lambda appears in an argument position and the underlying method is
overloaded.

For example, given

*interface Mapping<In, Out>
{
    Out map(In in);
}
interface IndexedMapping<In, Out>
{
    Out map(In in, int index);
}
interface Predicate<E>
{
    bool isSatisfied(E e);
}
interface MyList<E> {
    <U> MyList<U> map(Mapping<? super E, ? extends U> f) ...;
    <U> MyList<U> map(IndexedMapping<? super E, ? extends U> f) ...;
    MyList<E> filter(Predicate<? super E> p) ...
}
*

I would like to be able to write my lambdas with parameter types elided:
*
*
*MyList<X> list = ...;*
*MyList<Y> newList = list
    .map( #{ x -> new Y(x) } )
    .filter( #{ y -> y.IsFunny() } );*

This is all modulo syntax.  I'd prefer the syntax

*MyList<Y> newList = list
    .map( x -> new Y(x) )
    .filter( y -> y.IsFunny() );
*

but that is a discussion for another day (just let us know which day).

Cheers,
Neal