Inferring lambda parameter types in an argument position

[Rémi Forax]

On 03/04/2011 08:16 PM, Neal Gafter wrote:
> 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.

You're not the only one :)
It's on the ToDo list but we haven't discuss yet about that.

Rémi

> 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
>