Scala example source code file (Printers.scala)

This example Scala source code file (Printers.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

a, icodes, io, list, local, nil, nil, printers, printwriter, string, string, tab, tab, unit, unit

The Scala Printers.scala source code

/* NSC -- new scala compiler
 * Copyright 2005-2011 LAMP/EPFL
 * @author  Martin Odersky
 */


package scala.tools.nsc
package backend
package icode

import java.io.PrintWriter

import scala.tools.nsc.symtab.Flags
import scala.tools.nsc.util.Position

trait Printers { self: ICodes =>
  import global._
  import global.icodes.opcodes._
  import global.icodes._

  class TextPrinter(writer: PrintWriter, lin: Linearizer) {
    private var margin = 0
    private var out = writer

    final val TAB = 2
    
    def setWriter(w: PrintWriter) { out = w }

    def indent() { margin += TAB }
    def undent() { margin -= TAB }

    def print(s: String) { out.print(s) }
    def print(o: Any) { print(o.toString()) }

    def println(s: String) {
      print(s);
      println
    }

    def println() {
      out.println()
      var i = 0
      while (i < margin) {
        print(" ");
        i += 1
      }
    }

    def printList[A](l: List[A], sep: String): Unit = l match {
      case Nil =>
      case x :: Nil => print(x)
      case x :: xs  => print(x); print(sep); printList(xs, sep)
    }

    def printList[A](pr: A => Unit)(l: List[A], sep: String): Unit = l match {
      case Nil =>
      case x :: Nil => pr(x)
      case x :: xs  => pr(x); print(sep); printList(pr)(xs, sep)
    }

    def printClass(cls: IClass) {
      print(cls.symbol.toString()); print(" extends ");
      printList(cls.symbol.info.parents, ", ");
      indent; println(" {");
      println("// fields:");
      cls.fields.foreach(printField); println;
      println("// methods");
      cls.methods.foreach(printMethod);
      undent; println;
      println("}")
    }

    def printField(f: IField) {
      print(f.symbol.keyString); print(" ");
      print(f.symbol.nameString); print(": "); 
      println(f.symbol.info.toString());
    }

    def printMethod(m: IMethod) {
      print("def "); print(m.symbol.name); 
      print("("); printList(printParam)(m.params, ", "); print(")");
      print(": "); print(m.symbol.info.resultType)

      if (!m.isAbstractMethod) {
        println(" {")
        println("locals: " + m.locals.mkString("", ", ", ""))
        println("startBlock: " + m.code.startBlock)
        println("blocks: " + m.code.blocks.mkString("[", ",", "]"))
        println
        lin.linearize(m) foreach printBlock
        println("}")
        
        indent; println("Exception handlers: ")
        m.exh foreach printExceptionHandler

        undent; println
      } else
        println
    }

    def printParam(p: Local) {
      print(p.sym.name); print(": "); print(p.sym.info);
      print(" ("); print(p.kind); print(")")
    }

    def printExceptionHandler(e: ExceptionHandler) {
      indent;
      println("catch (" + e.cls.simpleName + ") in " + e.covered + " starting at: " + e.startBlock);
      println("consisting of blocks: " + e.blocks);
      undent;
      println("with finalizer: " + e.finalizer);
//      linearizer.linearize(e.startBlock) foreach printBlock;
    }

    def printBlock(bb: BasicBlock) {
      print(bb.label)
      if (bb.loopHeader) print("[loop header]")
      print(": ");
      if (settings.debug.value) print("pred: " + bb.predecessors + " succs: " + bb.successors + " flags: " + bb.flagsString)
      indent; println
      bb.toList foreach printInstruction
      undent; println
    }

    def printInstruction(i: Instruction) {
//      if (settings.Xdce.value)
//        print(if (i.useful) "   " else " * ");
      if (i.pos.isDefined) print(i.pos.line.toString + "\t") else print("?\t")
      println(i.toString())
    }
  }
}