Refining the reflection api.

In the pursuit of simplicity and consistency.

- Method names like getType, getClass, and getValue are far too ambiguous,
  both internally and especially with java reflection names.  Methods which
  accept or return scala symbols should not refer to them as "classes" in
  the reflection library.  (We can live with the FooClass convention for naming
  the well-known symbols, it's names like "getClass" and "classToType" which
  are needlessly conflationary.)
- Meaningless names like "subst" have to be expanded.
- We should hew closely to the terms which are used by scala programmers
  wherever possible, thus using "thisType" to mean "C.this" can only beget confusion,
  given that "thisType" doesn't mean "this.type" but what is normally called
  the "self type."
- It's either "enclosing" or "encl", not both, and similar consistency issues.
- Eliminated getAnnotations.
- Removed what I could get away with from the API; would like to push
  those which are presently justified as being "required for LiftCode" out of the core.
- Changed a number of AnyRefs to Any both on general principles and because
  before long it may actually matter.
- There are !!!s scattered all over this commit, mostly where I think
  the name could be better.
- I think we should standardize on method names like "vmSignature, vmClass" etc.
  when we are talking about jvm (and ostensibly other vm) things.
  There are a bunch more places to make this distinction clear (e.g.
  Symbol's javaBinaryName, etc.)
- There is a lot more I want to do on this and I don't know where the
  time will come from to do it.

Review by @odersky, @scalamacros.

1 files changed, 22 insertions, 15 deletions

diff --git a/src/compiler/scala/reflect/internal/Symbols.scala b/src/compiler/scala/reflect/internal/Symbols.scala
index b9ba269ee3..819d94f41a 100644
--- a/src/compiler/scala/reflect/internal/Symbols.scala
+++ b/src/compiler/scala/reflect/internal/Symbols.scala
@@ -61,13 +61,18 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
       case n: TermName => newTermSymbol(n, pos, newFlags)
       case n: TypeName => newTypeSymbol(n, pos, newFlags)
     }
-    def typeSig: Type = info
-    def typeSigIn(site: Type): Type = site.memberInfo(this)
+    def enclosingClass: Symbol            = enclClass
+    def enclosingMethod: Symbol           = enclMethod
+    def thisPrefix: Type                  = thisType
+    def selfType: Type                    = typeOfThis
+    def typeSignature: Type               = info
+    def typeSignatureIn(site: Type): Type = site memberInfo this
+    
     def asType: Type = tpe
     def asTypeIn(site: Type): Type = site.memberType(this)
     def asTypeConstructor: Type = typeConstructor
     def setInternalFlags(flag: Long): this.type = { setFlag(flag); this }
-    def setTypeSig(tpe: Type): this.type = { setInfo(tpe); this }
+    def setTypeSignature(tpe: Type): this.type = { setInfo(tpe); this }
     def setAnnotations(annots: AnnotationInfo*): this.type = { setAnnotations(annots.toList); this }
   }
 
@@ -103,12 +108,17 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
     def pos = rawpos
     def setPos(pos: Position): this.type = { this.rawpos = pos; this }
 
+    /** !!! The logic after "hasFlag" is far too opaque to be unexplained.
+     *  I'm guessing it's attempting to compensate for flag overloading,
+     *  and embedding such logic in an undocumented island like this is a
+     *  notarized guarantee of future breakage.
+     */
     override def hasModifier(mod: Modifier) =
       hasFlag(flagOfModifier(mod)) &&
       (!(mod == Modifier.bynameParameter) || isTerm) &&
       (!(mod == Modifier.covariant) || isType)
 
-    override def allModifiers: Set[Modifier] =
+    override def modifiers: Set[Modifier] =
       Modifier.values filter hasModifier
 
 // ------ creators -------------------------------------------------------------------
@@ -1271,14 +1281,11 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
     /** After the typer phase (before, look at the definition's Modifiers), contains
      *  the annotations attached to member a definition (class, method, type, field).
      */
-    def annotations: List[AnnotationInfo] = _annotations
+    def annotations: List[AnnotationInfo] = {
+      // Necessary for reflection, see SI-5423
+      if (inReflexiveMirror)
+        initialize
 
-    /** This getter is necessary for reflection, see https://issues.scala-lang.org/browse/SI-5423
-     *  We could auto-inject completion into `annotations' and `setAnnotations', but I'm not sure about that
-     *  @odersky writes: I fear we can't do the forcing for all compiler symbols as that could introduce cycles
-     */
-    def getAnnotations: List[AnnotationInfo] = {
-      initialize
       _annotations
     }
 
@@ -1572,10 +1579,10 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
       else owner.logicallyEnclosingMember
 
     /** The top-level class containing this symbol. */
-    def toplevelClass: Symbol =
+    def enclosingTopLevelClass: Symbol =
       if (owner.isPackageClass) {
         if (isClass) this else moduleClass
-      } else owner.toplevelClass
+      } else owner.enclosingTopLevelClass
 
     /** Is this symbol defined in the same scope and compilation unit as `that` symbol? */
     def isCoDefinedWith(that: Symbol) = (
@@ -1879,7 +1886,7 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
 */
     def sourceFile: AbstractFileType =
       if (isModule) moduleClass.sourceFile
-      else toplevelClass.sourceFile
+      else enclosingTopLevelClass.sourceFile
 
     def sourceFile_=(f: AbstractFileType) {
       abort("sourceFile_= inapplicable for " + this)
@@ -2611,7 +2618,7 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
     override def defString: String = toString
     override def locationString: String = ""
     override def enclClass: Symbol = this
-    override def toplevelClass: Symbol = this
+    override def enclosingTopLevelClass: Symbol = this
     override def enclMethod: Symbol = this
     override def sourceFile: AbstractFileType = null
     override def ownerChain: List[Symbol] = List()