Logging interpolator for Scala 3

README.md

interpolator-macros.scala

import scala.quoted.*

extension (inline ctx: StringContext)
  transparent inline def log(inline args: Any*): Any =
    ${ impl('ctx, 'args) }

inline private def col(inline f: Console.type => String, inline msg: Any) =
  f(Console) + msg.toString() + Console.RESET

private def impl(strCtxExpr: Expr[StringContext], argsExpr: Expr[Seq[Any]])(
    using Quotes
): Expr[Any] =
  val args: List[Expr[Any]] =
    val Varargs(args) = argsExpr: @unchecked
    args.toList
  end args
  val codecsBuilder = List.newBuilder[Expr[Any]]
  val segmentBuilders = List.newBuilder[Expr[Either[Int, String]]]

  args.foreach { expr =>
    expr match
      case '{ $other: String } =>
        segmentBuilders.addOne('{
          Right($other)
        })
      case '{ type t; $s: t } =>
        val e = Expr(expr.show)

        codecsBuilder.addOne('{

          val rend =
            if $s != null
            then $s.toString
            else col(_.RED, "null")

          col(_.GREEN, "[" + $e + " = ") +
            col(_.BLUE, col(_.BOLD, rend)) +
            col(_.GREEN, "]")
        })
  }

  val insertions =
    Expr.ofList(codecsBuilder.result() ++ segmentBuilders.result())

  '{
    val parts = $strCtxExpr.parts.map(Option.apply)
    val ins = $insertions.map(Option.apply)
    val sb = new StringBuilder

    parts.zipAll(ins, None, None).foreach { case (str, insertion) =>
      str.foreach(sb.append(_))
      insertion.foreach(sb.append(_))
    }

    println(sb.result)
  }
end impl

I think you may have to process escapes / check lengths in that interpolator: https://github.com/polyvariant/colorize-scala/blob/24308ba2b9d884d3747d0b3911fa46ce337845d6/core/shared/src/main/scala/org/polyvariant/colorize/custom/ConfiguredColorize.scala#L35-L49