False positive in missing interpolator warning

[scabug]

scala> object T; """foo \$T bar"""
<console>:13: warning: possible missing interpolator: detected interpolated identifier `$T`
 """foo \$T bar"""
 ^
defined object T
res0: String = foo \$T bar

but then..

scala> object T; s"""foo \$T bar"""
scala.StringContext$InvalidEscapeException: invalid escape at terminal index 4 in "foo \". Use \\ for literal \.
  at scala.StringContext$.loop$1(StringContext.scala:211)
  at scala.StringContext$.replace$1(StringContext.scala:246)
  at scala.StringContext$.treatEscapes0(StringContext.scala:250)
  at scala.StringContext$.treatEscapes(StringContext.scala:195)
  at scala.StringContext.$anonfun$s$1(StringContext.scala:95)
  at scala.StringContext.standardInterpolator(StringContext.scala:123)
  at scala.StringContext.s(StringContext.scala:95)
  ... 29 elided

N.B. the difference between line 1 and line 2 is the extra 's' before the string.

The compiler warns about a "possible missing interpolator" when no interpolation would occur.

workaround

Use the f-interpolator and double the "$"'s and the ""s:

scala> object T; f"""foo \\$$T bar"""
object T
val res2: String = foo \$T bar

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-10217?orig=1
Reporter: @dwijnand
Affected Versions: 2.12.1
See #6476, #8761

[scabug]

@dwijnand said:
The arch-enemy of #8761.

[scabug]

@som-snytt said:
Suggest renaming it -Xlint:possible-missing-interpolator.

#6476 means """\$""" does not unambiguously express escaped dollar.

For example, file"""C:\Program Files\$name""".

The linter could be improved to check only possible interpolators. -Xlint:possible-missing-possible-interpolator

If the interpolator is a macro, it could check for success before warning; but failure (like a bad escape) could mean I haven't worked out the confusing syntax yet.

I asked about the linked issue on gitter recently and nobody cared. As with shoes, one cares only if they pinch, or if they're really great shoes.

[scabug]

@dwijnand said:
I wouldn't infer anything from a forum such as a Gitter room.

In accordance to your new year's resolution: Do you think this is a bug or not?

[scabug]

@som-snytt said:
I think it's an improvement if the message were to indicate which available interpolators succeed or fail (if macros), otherwise assume failure.

[som-snytt]

The last suggestion was to suggest:

did you mean `raw"\$T"`?

That would be clever mind reading.

Closing as not a bug because of the example for windows file names.

Alternatively, use a hypothetical id"\$T" which does nothing but reconstruct the literal text.

As of 2.13, there is no warning for seeming to interpolate a module (object); and \ is escape for quote in strings and interpolations.