nodeprinters.scala

来自「JAVA 语言的函数式编程扩展」· SCALA 代码 · 共 368 行

/* NSC -- new Scala compiler
 * Copyright 2005-2007 LAMP/EPFL
 * @author  Martin Odersky
 */
// $Id: NodePrinters.scala 14683 2008-04-17 13:10:30Z washburn $

package scala.tools.nsc.ast

import compat.Platform.EOL
import symtab.Flags._

/** The object <code>nodePrinter</code> converts the internal tree
 *  representation to a string formatted as a Scala expression.
 *
 *  @author  Stephane Micheloud
 *  @version 1.0
 */
abstract class NodePrinters {

  val global: Global
  import global._

  object InfoLevel extends Enumeration {
    val Quiet, Normal, Verbose = Value
  }
  var infolevel = InfoLevel.Quiet

  object nodeToString extends Function1[Tree, String] {
    private val buf = new StringBuilder

    def apply(tree: Tree): String = {
      def traverse(tree: Tree, level: Int, comma: Boolean) {
        def println(s: String) {
          for (i <- 0 until level) buf.append("  ")
          buf.append(s)
          buf.append(EOL)
        }
        def printcln(s: String) {
          for (i <- 0 until level) buf.append("  ")
          buf.append(s)
          if (comma) buf.append(",")
          buf.append(EOL)
        }
        def annotationInfoToString(attr: AnnotationInfo) = {
          val str = new StringBuilder
          str.append(attr.atp.toString())
          if (!attr.args.isEmpty)
            str.append(attr.args.mkString("(", ",", ")"))
          if (!attr.assocs.isEmpty)
            for (((name, value), index) <- attr.assocs.zipWithIndex) {
              if (index > 0)
                str.append(", ")
              str.append(name).append(" = ").append(value)
            }
          str.toString
        }
        def symflags(tree: Tree): String = {
          val sym = tree.symbol
          val buf = new StringBuffer
          if (sym hasFlag IMPLICIT     ) buf.append(" | IMPLICIT")
          if (sym hasFlag FINAL        ) buf.append(" | FINAL")
          if (sym hasFlag PRIVATE      ) buf.append(" | PRIVATE")
          if (sym hasFlag PROTECTED    ) buf.append(" | PROTECTED")

          if (sym hasFlag SEALED       ) buf.append(" | SEALED")
          if (sym hasFlag OVERRIDE     ) buf.append(" | OVERRIDE")
          if (sym hasFlag CASE         ) buf.append(" | CASE")
          if (sym hasFlag ABSTRACT     ) buf.append(" | ABSTRACT")

          if (sym hasFlag DEFERRED     ) buf.append(" | DEFERRED")
          if (sym hasFlag METHOD       ) buf.append(" | METHOD")
          if (sym hasFlag MODULE       ) buf.append(" | MODULE")
          if (sym hasFlag INTERFACE    ) buf.append(" | INTERFACE")

          if (sym hasFlag MUTABLE      ) buf.append(" | MUTABLE")
          if (sym hasFlag PARAM        ) buf.append(" | PARAM")
          if (sym hasFlag PACKAGE      ) buf.append(" | PACKAGE")
          if (sym hasFlag DEPRECATED   ) buf.append(" | DEPRECATED")

          if (sym hasFlag COVARIANT    ) buf.append(" | COVARIANT")
          if (sym hasFlag CAPTURED     ) buf.append(" | CAPTURED")
          if (sym hasFlag BYNAMEPARAM  ) buf.append(" | BYNAMEPARAM")
          if (sym hasFlag CONTRAVARIANT) buf.append(" | CONTRVARIANT")
          if (sym hasFlag LABEL        ) buf.append(" | LABEL")
          if (sym hasFlag INCONSTRUCTOR) buf.append(" | INCONSTRUCTOR")
          if (sym hasFlag ABSOVERRIDE  ) buf.append(" | ABSOVERRIDE")
          if (sym hasFlag LOCAL        ) buf.append(" | LOCAL")
          if (sym hasFlag JAVA         ) buf.append(" | JAVA")
          if (sym hasFlag SYNTHETIC    ) buf.append(" | SYNTHETIC")
          if (sym hasFlag STABLE       ) buf.append(" | STABLE")
          if (sym hasFlag STATIC       ) buf.append(" | STATIC")

          if (sym hasFlag CASEACCESSOR ) buf.append(" | CASEACCESSOR")
          if (sym hasFlag TRAIT        ) buf.append(" | TRAIT")
          if (sym hasFlag BRIDGE       ) buf.append(" | BRIDGE")
          if (sym hasFlag ACCESSOR     ) buf.append(" | ACCESSOR")

          if (sym hasFlag SUPERACCESSOR) buf.append(" | SUPERACCESSOR")
          if (sym hasFlag PARAMACCESSOR) buf.append(" | PARAMACCESSOR")
          if (sym hasFlag MODULEVAR    ) buf.append(" | MODULEVAR")
          if (sym hasFlag SYNTHETICMETH) buf.append(" | SYNTHETICMETH")
          if (sym hasFlag MONOMORPHIC  ) buf.append(" | MONOMORPHIC")
          if (sym hasFlag LAZY         ) buf.append(" | LAZY")

          if (sym hasFlag IS_ERROR     ) buf.append(" | IS_ERROR")
          if (sym hasFlag OVERLOADED   ) buf.append(" | OVERLOADED")
          if (sym hasFlag LIFTED       ) buf.append(" | LIFTED")

          if (sym hasFlag MIXEDIN      ) buf.append(" | MIXEDIN")
          if (sym hasFlag EXISTENTIAL  ) buf.append(" | EXISTENTIAL")

          if (sym hasFlag EXPANDEDNAME ) buf.append(" | EXPANDEDNAME")
          if (sym hasFlag IMPLCLASS    ) buf.append(" | IMPLCLASS")
          if (sym hasFlag PRESUPER     ) buf.append(" | PRESUPER")
          if (sym hasFlag TRANS_FLAG   ) buf.append(" | TRANS_FLAG")
          if (sym hasFlag LOCKED       ) buf.append(" | LOCKED")

          val attrs = ", attrs=" + (
            if (!sym.attributes.isEmpty)
              sym.attributes.map(annotationInfoToString).mkString("[", ",", "]")
            else
              tree.asInstanceOf[MemberDef].mods.annotations)
          (if (buf.length() > 2) buf.substring(3)
          else "0") + ", // flags=" + flagsToString(sym.flags) + attrs
        }
        def nodeinfo(tree: Tree) =
          if (infolevel == InfoLevel.Quiet) ""
          else {
            val buf = new StringBuilder(" // sym=" + tree.symbol)
            if (tree.hasSymbol) {
              if (tree.symbol.isPrimaryConstructor)
                buf.append(", isPrimaryConstructor")
              else if (tree.symbol.isConstructor)
                buf.append(", isConstructor")
              if (tree.symbol != NoSymbol)
                buf.append(", sym.owner=" + tree.symbol.owner)
              buf.append(", sym.tpe=" + tree.symbol.tpe)
            }
            buf.append(", tpe=" + tree.tpe)
            if (tree.tpe != null) {
              var sym = tree.tpe.termSymbol
              if (sym == NoSymbol) sym = tree.tpe.typeSymbol
              buf.append(", tpe.sym=" + sym)
              if (sym != NoSymbol) {
                buf.append(", tpe.sym.owner=" + sym.owner)
                if ((infolevel > InfoLevel.Normal) &&
                    !(sym.owner eq definitions.ScalaPackageClass) &&
                    !sym.isModuleClass && !sym.isPackageClass &&
                    !sym.hasFlag(JAVA)) {
                  val members = for (m <- tree.tpe.decls.toList)
                    yield m.toString() + ": " + m.tpe + ", "
                  buf.append(", tpe.decls=" + members)
                }
              }
            }
            buf.toString
          }
        def nodeinfo2(tree: Tree) =
          (if (comma) "," else "") + nodeinfo(tree)
        tree match {
          case AppliedTypeTree(tpt, args) =>
            println("AppliedTypeTree(" + nodeinfo(tree))
            traverse(tpt, level + 1, true)
            if (args.isEmpty)
              println("  List() // no argument")
            else {
              val n = args.length
              println("  List( // " + n + " arguments(s)")
              for (i <- 0 until n)
                traverse(args(i), level + 2, i < n-1)
              println("  )")
            }
            printcln(")")
          case Apply(fun, args) =>
            println("Apply(" + nodeinfo(tree))
            traverse(fun, level + 1, true)
            if (args.isEmpty)
              println("  List() // no argument")
            else {
              val n = args.length
              println("  List( // " + n + " argument(s)")
              for (i <- 0 until n)
                traverse(args(i), level + 2, i < n-1)
              println("  )")
            }
            printcln(")")
          case ApplyDynamic(fun, args) =>
            println("ApplyDynamic(" + nodeinfo(tree))
            traverse(fun, level + 1, true)
            if (args.isEmpty)
              println("  List() // no argument")
            else {
              val n = args.length
              println("  List( // " + n + " argument(s)")
              for (i <- 0 until n)
                traverse(args(i), level + 2, i < n-1)
              println("  )")
            }
            printcln(")")
          case Block(stats, expr) =>
            println("Block(" + nodeinfo(tree))
            if (stats.isEmpty)
              println("  List() // no statement")
            else {
              val n = stats.length
              println("  List( // " + n + " statement(s)")
              for (i <- 0 until n)
                traverse(stats(i), level + 2, i < n-1)
              println("  )")
            }
            traverse(expr, level + 1, false)
            printcln(")")
          case ClassDef(mods, name, tparams, impl) =>
            println("ClassDef(" + nodeinfo(tree))
            println("  " + symflags(tree))
            println("  \"" + name + "\",")
            if (tparams.isEmpty)
              println("  List(), // no type parameter")
            else {
              val n = tparams.length
              println("  List( // " + n + " type parameter(s)")
              for (i <- 0 until n)
                traverse(tparams(i), level + 2, i < n-1)
              println("  ),")
            }
            traverse(impl, level + 1, false)
            printcln(")")
          case DefDef(mods, name, tparams, vparamss, tpt, rhs) =>
            println("DefDef(" + nodeinfo(tree))
            println("  " + symflags(tree))
            println("  \"" + name + "\",")
            if (tparams.isEmpty)
              println("  List(), // no type parameter")
            else {
              val n = tparams.length
              println("  List( // " + n + " type parameter(s)")
              for (i <- 0 until n)
                traverse(tparams(i), level + 2, i < n-1)
              println("  ),")
            }
            val n = vparamss.length
            if (n == 1 && vparamss(0).isEmpty)
              println("  List(List()), // no parameter")
            else {
              println("  List(")
              for (i <- 0 until n) {
                val m = vparamss(i).length
                println("    List( // " + m + " parameter(s)")
                for (j <- 0 until m)
                  traverse(vparamss(i)(j), level + 3, j < m-1)
                println("    )")
              }
              println("  ),")
            }
            println("  " + tpt + ",")
            traverse(rhs, level + 1, false)
            printcln(")")
          case EmptyTree =>
            printcln("EmptyTree")
          case Ident(name) =>
            printcln("Ident(\"" + name + "\")" + nodeinfo2(tree))
          case Literal(value) =>
            printcln("Literal(" + value + ")")
          case New(tpt) =>
            println("New(" + nodeinfo(tree))
            traverse(tpt, level + 1, false)
            printcln(")")
          case Select(qualifier, selector) =>
            println("Select(" + nodeinfo(tree))
            traverse(qualifier, level + 1, true)
            printcln("  \"" + selector + "\")")
          case Super(qual, mix) =>
            printcln("Super(\"" + qual + "\", \"" + mix + "\")" + nodeinfo2(tree))
          case Template(parents, self, body) =>
            println("Template(" + nodeinfo(tree))
            println("  " + parents.map(p => if (p.tpe ne null) p.tpe.typeSymbol else "null-" + p) + ", // parents")
            traverse(self, level + 1, true)    
            if (body.isEmpty)
              println("  List() // no body")
            else {
              val n = body.length
              println("  List( // body")
              for (i <- 0 until n)
                traverse(body(i), level + 2, i < n-1)
              println("  )")
            }
            printcln(")")
          case This(qual) =>
            println("This(\"" + qual + "\")" + nodeinfo2(tree))
          case TypeApply(fun, args) =>
            println("TypeApply(" + nodeinfo(tree))
            traverse(fun, level + 1, true)
            if (args.isEmpty)
              println("  List() // no argument")
            else {
              val n = args.length
              println("  List(")
              for (i <- 0 until n)
                traverse(args(i), level + 1, i < n-1)
              println("  )")
            }
            printcln(")")
          case TypeTree() =>
            printcln("TypeTree()" + nodeinfo2(tree))
          case Typed(expr, tpt) =>
            println("Typed(" + nodeinfo(tree))
            traverse(expr, level + 1, true)
            traverse(tpt, level + 1, false)
            printcln(")")
          case ValDef(mods, name, tpt, rhs) =>
            println("ValDef(" + nodeinfo(tree))
            println("  " + symflags(tree))
            println("  \"" + name + "\",")
            traverse(tpt, level + 1, true)
            traverse(rhs, level + 1, false)
            printcln(")")
          case PackageDef(name, stats) =>
            println("PackageDef("+name+", ")
            for (stat <- stats)
              traverse(stat, level + 1, false)
            printcln(")")
          case _ =>
            tree match {
              case p: Product =>
                if (p.productArity != 0) {
                  println(p.productPrefix+"(")
                  for (elem <- (0 until p.productArity) map p.productElement) {
                    def printElem(elem: Any, level: Int): Unit = elem match {
                      case t: Tree => 
                        traverse(t, level, false)
                      case xs: List[_] => 
                        print("List(")
                        for (x <- xs) printElem(x, level+1)
                        printcln(")")
                      case _ => 
                        println(elem.toString)
                    }
                    printElem(elem, level+1)
                  }
                  printcln(")")                
                } else printcln(p.productPrefix)
              case _ => 
                printcln("***" + tree.getClass)
            }
        }
      }
      buf setLength 0
      traverse(tree, 0, false)
      buf.toString
    }
  }

  def printUnit(unit: CompilationUnit) {
    print("// Scala source: " + unit.source + "\n")
    if (unit.body ne null) {
      print(nodeToString(unit.body)); println()
    } else {
      print("<null>")
    }
    println()
  }

  def printAll() {
    print("[[syntax trees at end of " + phase + "]]")
    for (unit <- global.currentRun.units) printUnit(unit)
  }
}