Allow single line case if it fits on line

[olafurpg]

From @lihaoyi on Gitter.

How is it that sometimes it puts case (foo, bar) => on a new line, and sometimes it doesn't:

-        .action { (x, c) => c.copy(file = Some(Path(x, cwd))) }
+        .action { (x, c) =>
+          c.copy(file = Some(Path(x, cwd)))
+        }

but

-    val reads = paramSymbols.zip(apply.args).map{ case (param, term) =>
-      val assign = term match{
-        case q"ammonite.repl.ScriptInit.arg($inner)" =>
-
-          val newPrefix = q"ammonite.repl.ScriptInit.parseScriptArg"
-          q"$newPrefix[${param.typeSignature}](${param.name.decoded}, $inner)"
-        case x => x // This case should only be for default args, which we leave unchanged
-      }
-      assign
+    val reads = paramSymbols.zip(apply.args).map {
+      case (param, term) =>
+        val assign = term match {
+          case q"ammonite.repl.ScriptInit.arg($inner)" =>
+            val newPrefix = q"ammonite.repl.ScriptInit.parseScriptArg"
+            q"$newPrefix[${param.typeSignature}](${param.name.decoded}, $inner)"
+          case x =>
+            x // This case should only be for default args, which we leave unchanged
+        }
+        assign
     }

[olafurpg]

For some reason I can't find a solution I'm happy with, I got really deep into issues with the pruneSlowStates optimization until I gave. Saving this issue for a later release, 0.2.1 is already useful as it is.

[tindzk]

I think the same rule should apply to the implicit keyword. An example:

DOM.render { implicit ctx =>
  ...
}

Currently, it gets indented as follows:

DOM.render {
  implicit ctx =>
    ...
}

[olafurpg]

Closing as won't fix.

[ches]

@olafurpg I thought I recalled seeing a reference to why this is wontfix, maybe it is elsewhere. Was it something hoped that could be addressed through Paiges (or conclusively cannot), or due to Scala 3 potentially not needing the case anyway, or something else?

[olafurpg]

Mostly closed since I don't think it's worth pursuing with the current implementation. A tree printer with paiges should make it easier to support this desirable output.