Abstract error message only show the start of the name

[tgodzik]

Compiler version

If you're not sure what version you're using, run print scalaVersion from sbt
(if you're running scalac manually, use scalac -version instead).

Minimized code

//> using scala 3

trait Foo:
  def bar: String

class Baz extends Foo:
  val a = "hello"

Output

-- Error: /Users/tgodzik/Documents/workspaces/test-sample/test1.scala:6:6 ------
6 |class Baz extends Foo:
  |      ^
  |class Baz needs to be abstract, since def bar: String in trait Foo is not defined 
1 error found
Compilation failed

Expectation

-- Error: /Users/tgodzik/Documents/workspaces/test-sample/test1.scala:6:6 ------
6 |class Baz extends Foo:
  |      ^^^
  |class Baz needs to be abstract, since def bar: String in trait Foo is not defined 
1 error found
Compilation failed

My guess is that it needs to be fixed around

scala3/compiler/src/dotty/tools/dotc/typer/RefChecks.scala

Line 944 in b1575f0

report.error(abstractErrorMessage, clazz.srcPos)

[tgodzik]

Could this just be a case of using something different than .srcPos, or might it be some lack of copying the span at some point?

[som-snytt]

Named trees have a name pos, and the pos of a symbol is its name. (IIRC this is true for both Scala 2 & 3 now.)

Hmm, it starts correct but then span becomes degenerate. I guess I'm wrong about scala 3 symbols:

This is always a zero-extent position.

I never read Spans all the way to the end.

  /** The coordinate of a symbol. This is either an index or
   *  a zero-range span.
   */

TIL. Also implicit conversions really are evil.