Bring back old completions as a deprecated method

compiler/src/dotty/tools/repl/ReplDriver.scala

@@ -163,7 +163,7 @@ class ReplDriver(settings: Array[String],
             /* complete = */ false  // if true adds space when completing
           )
         }
-        val comps = completions(line.cursor, line.line, state)
+        val comps = completionsWithSignatures(line.cursor, line.line, state)
         candidates.addAll(comps.map(_.label).distinct.map(makeCandidate).asJava)
         val lineWord = line.word()
         comps.filter(c => c.label == lineWord && c.symbols.nonEmpty) match
@@ -255,8 +255,22 @@ class ReplDriver(settings: Array[String],
     else
       label
 
+  @deprecated("Use completionsWithSignatures instead", "3.4.2")
+  protected final def completions(cursor: Int, expr: String, state0: State): List[Candidate] =
+    completionsWithSignatures(cursor, expr, state0).map: c =>
+      new Candidate(
+        /* value    = */ c.label,
+        /* displ    = */ stripBackTicks(c.label), // displayed value
+        /* group    = */ null,  // can be used to group completions together
+        /* descr    = */ null,  // TODO use for documentation?
+        /* suffix   = */ null,
+        /* key      = */ null,
+        /* complete = */ false  // if true adds space when completing
+      )
+  end completions
+
   /** Extract possible completions at the index of `cursor` in `expr` */
-  protected final def completions(cursor: Int, expr: String, state0: State): List[Completion] =
+  protected final def completionsWithSignatures(cursor: Int, expr: String, state0: State): List[Completion] =
     if expr.startsWith(":") then
       ParseResult.commands.collect {
         case command if command._1.startsWith(expr) => Completion(command._1, "", List())
@@ -275,7 +289,7 @@ class ReplDriver(settings: Array[String],
           try Completion.completions(srcPos)._2 catch case NonFatal(_) => Nil
         }
         .getOrElse(Nil)
-  end completions
+  end completionsWithSignatures
 
   protected def interpret(res: ParseResult, quiet: Boolean = false)(using state: State): State = {
     res match {

compiler/test/dotty/tools/repl/ReplTest.scala

@@ -42,7 +42,7 @@ extends ReplDriver(options, new PrintStream(out, true, StandardCharsets.UTF_8.na
 
   /** Returns the `(<instance completions>, <companion completions>)`*/
   def tabComplete(src: String)(implicit state: State): List[String] =
-    completions(src.length, src, state).map(_.label).sorted.distinct
+    completionsWithSignatures(src.length, src, state).map(_.label).sorted.distinct
 
   extension [A](state: State)
     infix def andThen(op: State ?=> A): A = op(using state)