Fix #1503: be more careful where to insert apply #1522
Conversation
| @@ -927,15 +927,25 @@ object Types { | |||
| def narrow(implicit ctx: Context): TermRef = | |||
| TermRef(NoPrefix, ctx.newSkolem(this)) | |||
|
|
|||
| /** Useful for diagnsotics: The underlying type if this type is a type proxy, | |||
| /** Useful for diagnsotics: The underlying type if this type is a type proxy, | |||
| * otherwise NoType | |||
There was a problem hiding this comment.
Nitpick: weird indent doesn't match next row
| def isWeakProto: Boolean = false | ||
|
|
||
| /** Overridden in FunProto and PolyProto */ | ||
| def weakenProto: Type = this |
|
This now compiles: val foo = () => println("hi")
val bar = () => println("there")
(if (1 == 1) foo else bar)()But this doesn't: def foo() = println("hi")
def bar() = println("there")
(if (1 == 1) foo else bar)()Stack trace: https://gist.github.com/smarter/91f610d4efb8cdaedff16d9b032d346c (With scalac, error: Unit does not take parameters
(if (1 == 1) foo else bar)()
^) |
`apply` nodes should not be inserted in the result parts of a block, if-then-else, match, or try. Instead they should be added to the surrounding statement.
|
@smarter Well spotted. I replaced the PR with a new version which fixes the problem and is simpler than the previous one. |
|
That's similar to a fix we tried with Felix except we gave up when we got type errors and didn't try to introduce something like |
| * otherwise NoType | ||
| */ | ||
| def underlyingIfProxy(implicit ctx: Context) = this match { | ||
| case this1: TypeProxy => this1.underlying | ||
| case _ => NoType | ||
| } | ||
|
|
||
| // ----- Normalizing typerefs over refined types ---------------------------- | ||
| /** If this is a FunProto or PolyProto, WildcardType, otherwise this */ |
There was a problem hiding this comment.
- Two extra spaces in the indentation
- This comment should explain the purpose of
notAppliedlike the commit message does
There was a problem hiding this comment.
I'm also not entirely sure why using WildcardType does not break type inference in some cases, maybe this could be explained here
| @@ -572,7 +572,8 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit | |||
| def typedBlock(tree: untpd.Block, pt: Type)(implicit ctx: Context) = track("typedBlock") { | |||
| val exprCtx = index(tree.stats) | |||
| val stats1 = typedStats(tree.stats, ctx.owner) | |||
| val expr1 = typedExpr(tree.expr, pt)(exprCtx) | |||
| val ept = if (tree.isInstanceOf[untpd.InfixOpBlock]) pt else pt.notApplied | |||
There was a problem hiding this comment.
Add a comment explaining why InfixOpBlock is treated specially here, also a match would be cleaner and safer than isInstanceOf
Fixes #1503 and related problems which are presented in i1503.scala.
This was a more fundamental problem to type inference than it appeared at first.
Review by @nicolasstucki or @felixmulder or @smarter.