Semantic printing

When refined printing a DefTree, if one is after typer,
print the symbol's definition plus the rhs of the tree
rather than the contents of the tree.

Why: After typer, it's always the symbol's contents that should matter.

Question: Can we enforce through the types that parts of DefTree reflected
by the symbol disappear/are ignored?

1 files changed, 17 insertions, 9 deletions

diff --git a/src/dotty/tools/dotc/printing/RefinedPrinter.scala b/src/dotty/tools/dotc/printing/RefinedPrinter.scala
index 017434aa4..acba22afe 100644
--- a/src/dotty/tools/dotc/printing/RefinedPrinter.scala
+++ b/src/dotty/tools/dotc/printing/RefinedPrinter.scala
@@ -194,7 +194,10 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
       case _ => toTextGlobal(arg)
     }
 
-    def idText = if (ctx.settings.uniqid.value) "#" + tree.symbol.id else ""
+    def dclTextOr(treeText: => Text) =
+      if (ctx.isAfterTyper(ctx.phase) && tree.symbol != null && tree.symbol.exists)
+        annotsText(tree.symbol) ~~ dclText(tree.symbol)
+      else treeText
 
     import untpd._
 
@@ -285,19 +288,24 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
         "(" ~ toTextGlobal(patterns, ", ") ~ ")" ~
         ("(" ~ toTextGlobal(implicits, ", ") ~ ")" provided implicits.nonEmpty)
       case ValDef(mods, name, tpt, rhs) =>
-        modText(mods, if (mods is Mutable) "var" else "val") ~~ toText(name) ~ idText ~
-          optAscription(tpt) ~ optText(rhs)(" = " ~ _)
+        dclTextOr {
+          modText(mods, if (mods is Mutable) "var" else "val") ~~ toText(name) ~
+            optAscription(tpt)
+        } ~ optText(rhs)(" = " ~ _)
       case DefDef(mods, name, tparams, vparamss, tpt, rhs) =>
         atOwner(tree) {
-          val first = modText(mods, "def") ~~ toText(name) ~ idText ~ tparamsText(tparams)
-          addVparamssText(first, vparamss) ~ optAscription(tpt) ~ optText(rhs)(" = " ~ _)
+          dclTextOr {
+            val first = modText(mods, "def") ~~ toText(name) ~ tparamsText(tparams)
+            addVparamssText(first, vparamss) ~ optAscription(tpt)
+          } ~ optText(rhs)(" = " ~ _)
         }
       case tree @ TypeDef(mods, name, rhs) =>
         atOwner(tree) {
-          def typeDefText(rhsText: Text) = {
-            val rhsText1 = if (tree.hasType) toText(tree.symbol.info) else rhsText
-            modText(mods, "type") ~~ toText(name) ~ idText ~ tparamsText(tree.tparams) ~ rhsText1
-          }
+          def typeDefText(rhsText: Text) =
+            dclTextOr {
+              val rhsText1 = if (tree.hasType) toText(tree.symbol.info) else rhsText
+              modText(mods, "type") ~~ toText(name) ~ tparamsText(tree.tparams) ~ rhsText1
+            }
           rhs match {
             case impl: Template =>
               modText(mods, if (mods is Trait) "trait" else "class") ~~ toText(name) ~ toText(impl) ~