Scala example source code file (Printers.scala)

This example Scala source code file (Printers.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

a, compiler, icodes, list, local, nil, nsc, printers, printwriter, string, tab, unit

The Printers.scala Scala example source code

/* NSC -- new scala compiler
 * Copyright 2005-2013 LAMP/EPFL
 * @author  Martin Odersky
 */

package scala.tools.nsc
package backend
package icode

import java.io.PrintWriter

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

  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.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.toSeq.sortBy(_.label) + " 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) 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())
    }
  }
}