Add definition of Errors

Author: liufengyun

compiler/src/dotty/tools/dotc/transform/init/Errors.scala

@@ -0,0 +1,61 @@
+package dotty.tools.dotc
+package transform
+package init
+
+import ast.tpd._
+
+import core._
+import Decorators._
+import Types._, Symbols._, Contexts._
+
+import Effects._, Potentials._
+
+object Errors {
+  type Errors = Set[Error]
+  val empty: Errors = Set.empty
+
+  sealed trait Error {
+    def trace: Vector[Tree]
+    def report(implicit ctx: Context): Unit
+
+    def stacktrace(implicit ctx: Context): String = {
+      var indentCount = 0
+      var last = ""
+      val sb = new StringBuilder
+      trace.foreach { tree =>
+        indentCount += 1
+        val pos = tree.sourcePos
+        val line = "[ " + pos.source.file.name + ":" + (pos.line + 1) + " ]"
+        if (last != line)
+          sb.append(
+            if (pos.source.exists)
+              i"${ " " * indentCount }-> ${pos.lineContent.trim}\t$line\n"
+            else
+              i"${tree.show}\n"
+          )
+        last = line
+      }
+      sb.toString
+    }
+  }
+
+  /** Access non-initialized field */
+  case class AccessNonInit(field: Symbol, trace: Vector[Tree]) extends Error {
+    def report(implicit ctx: Context): Unit = ???
+  }
+
+  /** Promote `this` under initialization to fully-initialized */
+  case class PromoteThis(pot: ThisRef, trace: Vector[Tree]) extends Error {
+    def report(implicit ctx: Context): Unit = ???
+  }
+
+  /** Promote a cold value under initialization to fully-initialized */
+  case class PromoteCold(trace: Vector[Tree]) extends Error {
+    def report(implicit ctx: Context): Unit = ???
+  }
+
+  /** Promote a value under initialization to fully-initialized */
+  case class UnsafePromotion(pot: Potential, trace: Vector[Tree], errors: Set[Error]) extends Error {
+    def report(implicit ctx: Context): Unit = ???
+  }
+}