Implement API for errors

Author: anatoliykmetyuk

library/src/scala/compiletime/testing/package.scala

@@ -4,6 +4,15 @@ import scala.quoted._
 
 package object testing {
 
+  case class Error(message: String, lineContent: String, column: Int, kind: ErrorKind)
+
+  /** An error can be either a parse-time or a typecheck-time */
+  sealed trait ErrorKind  // TODO make this enum, so far not doable because ScalaJS compilation fails on it
+
+  object ErrorKind
+    case object Parser extends ErrorKind
+    case object Typer extends ErrorKind
+
   /** Whether the code type checks in the current context?
    *
    *  @param code The code to be type checked