[nem-en] Compare two MType

[Michal Moskal]

On 11/23/06, Michal Moskal <michal.moskal at gmail.com> wrote:
> On 11/22/06, vc <vc at rsdn.ru> wrote:
> > > In completion I need compare two MType.
> > >
> > > I try to use MType.TryProvide(), but in some case it is get wrong result.
> > >
> > > For example, if type1 is 'array[string]' and type2 is 'array[T.123]' the
> > > TryProvide() return false. But me need interpret it as same type.
> > >
> > > What me need to do?
> >
> > Me need filter extension methods for completion list. See ncc\typing\Typer.n
> > lile 1464.
>
> You need to call GetFreshType() on the method, ignore TyVars and match
> MType returned against MType.Fun. It will have T.123 replaced with a
> fresh type variable that will be substitued with string.

Or, better yet do a (untested):

match (ty.TypeOfMethod (meth).Fix ()) {
  | Fun (from, _) =>
    match (from.Fix ().GetFunctionArguments ()) {
       | t1 :: _ => ty.TryProvide (t1)
       | _ => false
    }
  | _ => Util.ice ()
}

which should also work when the defing class of an extension method is
generic (as oposed to just the method being generic).

-- 
   Michał