Fix compile in Scala 2.10.1+

[pbrant]

Scala 2.10.1 includes a type checking bug fix that causes compilation to
fail. Add casts to work around this (effectively restoring the previous
behavior).

[farmdawgnation]

So, do we want to add an if isInstanceOf[T => T] to these case statements as well? As such, this will throw an exception if it can't fit into the type. May not be a horrible idea to log a warning or something as well...

[Shadowfiend]

I'm down for the isInstanceOf check, though it's worth mentioning that AFilter should already be providing a compiler check for the type. I think the only real concern here is reflection or something similarly weird that would ignore the compiler and run in a type-erased context could theoretically send in something other than what's expected.

[pbrant]

The compiler verification on AFilter construction isn't sufficient. 2.10.0
and earlier didn't complain and happily assumed T => T. 2.10.1+ does
complain. See https://issues.scala-lang.org/browse/SI-5189 . The cast is
basically restoring the pre-2.10.1 behavior (which is wrong, but mostly
good enough).

On Fri, Dec 20, 2013 at 3:17 PM, Antonio Salazar Cardozo <
notifications@github.com> wrote:

In web/webkit/src/main/scala/net/liftweb/http/LiftScreen.scala:

@@ -360,7 +360,7 @@ trait AbstractScreen extends Factory {
case AVal(v: (T => List[FieldError])) => v
},
stuff.toList.collect {

•    case AFilter(v) => v
  

•    case AFilter(v) => v.asInstanceOf[T => T]
  

I'm down for the isInstanceOf check, though it's worth mentioning that
AFilter should already be providing a compiler check for the type. I
think the only real concern here is reflection or something similarly weird
that would ignore the compiler and run in a type-erased context could
theoretically send in something other than what's expected.

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Reply to this email directly or view it on GitHubhttps://github.com//pull/1509/files#r8500039
.

[Shadowfiend]

I realize that. I'm not saying asInstanceOf isn't necessary, I'm saying isInstanceOf might be too much, depending on whether we view this as dealing with something we know but the compiler doesn't, or whether we view this as dealing with the potential for someone to get around the compiler to give us bad data :)

[fmpwizard]

I'll let you guys decide on this one, once you all agree, just let me know and I'll press the green merge button (or any of you could do it too :) )

[Shadowfiend]

Is this ready to go, @pbrant ? I don't know if you decided either way on the isInstanceOf check above.

[pbrant]

I don't have any better ideas (i.e. I think it's good to go).

On Thu, Jan 16, 2014 at 3:38 PM, Antonio Salazar Cardozo <
notifications@github.com> wrote:

Is this ready to go, @pbrant https://github.com/pbrant ? I don't know
if you decided either way on the isInstanceOf check above.

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Reply to this email directly or view it on GitHubhttps://github.com//pull/1509#issuecomment-32473676
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