use new infer expected type for singleton complations (#21421)

Author: tgodzik

presentation-compiler/src/main/dotty/tools/pc/InferExpectedType.scala

@@ -7,6 +7,7 @@ import dotty.tools.dotc.core.Contexts.Context
 import dotty.tools.dotc.core.Flags
 import dotty.tools.dotc.core.StdNames
 import dotty.tools.dotc.core.Symbols
+import dotty.tools.dotc.core.Symbols.defn
 import dotty.tools.dotc.core.Types.*
 import dotty.tools.dotc.core.Types.Type
 import dotty.tools.dotc.interactive.Interactive
@@ -61,7 +62,7 @@ class InferExpectedType(
 object InterCompletionType:
   def inferType(path: List[Tree])(using Context): Option[Type] =
     path match
-      case (lit: Literal) :: Select(Literal(_), _) :: Apply(Select(Literal(_), _), List(Literal(Constant(null)))) :: rest => inferType(rest, lit.span)
+      case (lit: Literal) :: Select(Literal(_), _) :: Apply(Select(Literal(_), _), List(s: Select)) :: rest if s.symbol == defn.Predef_undefined => inferType(rest, lit.span)
       case ident :: rest => inferType(rest, ident.span)
       case _ => None
 

presentation-compiler/src/main/dotty/tools/pc/completions/SingletonCompletions.scala

@@ -7,18 +7,13 @@ import dotty.tools.pc.completions.CompletionValue.SingletonValue
 import dotty.tools.dotc.ast.tpd.*
 import dotty.tools.dotc.core.Constants.Constant
 import dotty.tools.dotc.core.Contexts.Context
-import dotty.tools.dotc.core.Flags
-import dotty.tools.dotc.core.StdNames
 import dotty.tools.dotc.core.Symbols
 import dotty.tools.dotc.core.Types.AndType
 import dotty.tools.dotc.core.Types.AppliedType
 import dotty.tools.dotc.core.Types.ConstantType
 import dotty.tools.dotc.core.Types.OrType
-import dotty.tools.dotc.core.Types.TermRef
 import dotty.tools.dotc.core.Types.Type
 import dotty.tools.dotc.core.Types.TypeRef
-import dotty.tools.dotc.util.Spans.Span
-import dotty.tools.dotc.core.Symbols.defn
 
 object SingletonCompletions:
   def contribute(
@@ -55,79 +50,3 @@ object SingletonCompletions:
         collectSingletons(tpe1).intersect(collectSingletons(tpe2))
       case _ => Nil
 
-object InterCompletionType:
-  def inferType(path: List[Tree])(using Context): Option[Type] =
-    path match
-      case (lit: Literal) :: Select(Literal(_), _) :: Apply(Select(Literal(_), _), List(s: Select)) :: rest if s.symbol == defn.Predef_undefined =>
-        inferType(rest, lit.span)
-      case ident :: rest => inferType(rest, ident.span)
-      case _ => None
-
-  def inferType(path: List[Tree], span: Span)(using Context): Option[Type] =
-    path match
-      case Apply(head, List(p : Select)) :: rest if p.name == StdNames.nme.??? && p.qualifier.symbol.name == StdNames.nme.Predef && p.span.isSynthetic =>
-        inferType(rest, span)
-      case Block(_, expr) :: rest if expr.span.contains(span) =>
-        inferType(rest, span)
-      case If(cond, _, _) :: rest if !cond.span.contains(span) =>
-        inferType(rest, span)
-      case Typed(expr, tpt) :: _ if expr.span.contains(span) && !tpt.tpe.isErroneous => Some(tpt.tpe)
-      case Block(_, expr) :: rest if expr.span.contains(span) =>
-        inferType(rest, span)
-      case Bind(_, body) :: rest if body.span.contains(span) => inferType(rest, span)
-      case Alternative(_) :: rest => inferType(rest, span)
-      case Try(block, _, _) :: rest if block.span.contains(span) => inferType(rest, span)
-      case CaseDef(_, _, body) :: Try(_, cases, _) :: rest if body.span.contains(span) && cases.exists(_.span.contains(span)) => inferType(rest, span)
-      case If(cond, _, _) :: rest if !cond.span.contains(span) => inferType(rest, span)
-      case CaseDef(_, _, body) :: Match(_, cases) :: rest if body.span.contains(span) && cases.exists(_.span.contains(span)) =>
-        inferType(rest, span)
-      case NamedArg(_, arg) :: rest if arg.span.contains(span) => inferType(rest, span)
-      // x match
-      //  case @@
-      case CaseDef(pat, _, _) :: Match(sel, cases) :: rest if pat.span.contains(span) && cases.exists(_.span.contains(span)) && !sel.tpe.isErroneous =>
-        sel.tpe match
-          case tpe: TermRef => Some(tpe.symbol.info).filterNot(_.isErroneous)
-          case tpe => Some(tpe)
-      // List(@@)
-      case SeqLiteral(_, tpe) :: _ if !tpe.tpe.isErroneous =>
-        Some(tpe.tpe)
-      // val _: T = @@
-      // def _: T = @@
-      case (defn: ValOrDefDef) :: rest if !defn.tpt.tpe.isErroneous => Some(defn.tpt.tpe)
-      // f(@@)
-      case (app: Apply) :: rest =>
-        val param =
-          for {
-            ind <- app.args.zipWithIndex.collectFirst {
-              case (arg, id) if arg.span.contains(span) => id
-            }
-            params <- app.symbol.paramSymss.find(!_.exists(_.isTypeParam))
-            param <- params.get(ind)
-          } yield param.info
-        param match
-          // def f[T](a: T): T = ???
-          // f[Int](@@)
-          // val _: Int = f(@@)
-          case Some(t : TypeRef) if t.symbol.is(Flags.TypeParam) =>
-            for {
-              (typeParams, args) <-
-                app match
-                  case Apply(TypeApply(fun, args), _) =>
-                    val typeParams = fun.symbol.paramSymss.headOption.filter(_.forall(_.isTypeParam))
-                    typeParams.map((_, args.map(_.tpe)))
-                  // val f: (j: "a") => Int
-                  // f(@@)
-                  case Apply(Select(v, StdNames.nme.apply), _) =>
-                      v.symbol.info match
-                        case AppliedType(des, args) =>
-                          Some((des.typeSymbol.typeParams, args))
-                        case _ => None
-                  case _ => None
-              ind = typeParams.indexOf(t.symbol)
-              tpe <- args.get(ind)
-              if !tpe.isErroneous
-            } yield tpe
-          case Some(tpe) => Some(tpe)
-          case _ => None
-      case _ => None
-