StringBuilder helper function to reduce lots of...

StringBuilder helper function to reduce lots of code duplication.

9 files changed, 65 insertions, 107 deletions

diff --git a/src/library/scala/xml/EntityRef.scala b/src/library/scala/xml/EntityRef.scala
index 9ce63d81f9..f660695ae1 100644
--- a/src/library/scala/xml/EntityRef.scala
+++ b/src/library/scala/xml/EntityRef.scala
@@ -42,7 +42,7 @@ case class EntityRef(entityName: String) extends SpecialNode {
     case "amp"  => "&"
     case "apos" => "'"
     case "quot" => "\""
-    case _ => val sb = new StringBuilder(); buildString(sb).toString()
+    case _      => Utility.sbToString(buildString)
   }
 
   /** Appends "& entityName;" to this string buffer.
diff --git a/src/library/scala/xml/Group.scala b/src/library/scala/xml/Group.scala
index 4831514fd4..9e18ecb5f0 100644
--- a/src/library/scala/xml/Group.scala
+++ b/src/library/scala/xml/Group.scala
@@ -60,12 +60,4 @@ case class Group(val nodes: Seq[Node]) extends Node {
   def buildString(sb: StringBuilder) =
     throw new UnsupportedOperationException(
       "class Group does not support method toString(StringBuilder)")
-
-  override def text = { // same impl as NodeSeq
-    val sb = new StringBuilder()
-    val it = elements
-    while (it.hasNext)
-      sb.append(it.next.text)
-    sb.toString()
-  }
 }
diff --git a/src/library/scala/xml/MetaData.scala b/src/library/scala/xml/MetaData.scala
index 71d6befc20..bca5fe08a1 100644
--- a/src/library/scala/xml/MetaData.scala
+++ b/src/library/scala/xml/MetaData.scala
@@ -11,6 +11,8 @@
 
 package scala.xml
 
+import Utility.sbToString
+
 /**
  * Copyright 2008 Google Inc. All Rights Reserved.
  * @author Burak Emir <bqe@google.com>
@@ -234,20 +236,12 @@ abstract class MetaData extends Collection[MetaData] {
 
   override def hashCode(): Int
 
-  def toString1(): String = {
-    val sb = new StringBuilder()
-    toString1(sb)
-    sb.toString()
-  }
+  def toString1(): String = sbToString(toString1)
 
   //appends string representations of single attribute to StringBuilder
   def toString1(sb:StringBuilder): Unit
 
-  override def toString(): String = {
-    val sb = new StringBuilder()
-    buildString(sb)
-    sb.toString()
-  }
+  override def toString(): String = sbToString(buildString)
 
   def buildString(sb: StringBuilder): StringBuilder = {
     sb.append(' ')
diff --git a/src/library/scala/xml/NamespaceBinding.scala b/src/library/scala/xml/NamespaceBinding.scala
index 7605fbacd2..9af256501c 100644
--- a/src/library/scala/xml/NamespaceBinding.scala
+++ b/src/library/scala/xml/NamespaceBinding.scala
@@ -12,6 +12,7 @@
 package scala.xml
 
 import Predef._
+import Utility.sbToString
 
 /** The class <code>NamespaceBinding</code> represents namespace bindings
  *  and scopes. The binding for the default namespace is treated as a null
@@ -42,18 +43,9 @@ class NamespaceBinding(val prefix: String,
   def getPrefix(_uri: String): String =
     if (_uri == uri) uri else parent.getURI(_uri)
 
-  override def toString(): String = {
-    val sb = new StringBuilder()
-    buildString(sb, TopScope)
-    sb.toString()
-  }
-
-  def buildString(stop: NamespaceBinding): String = {
-    val sb = new StringBuilder()
-    buildString(sb, stop)
-    sb.toString()
-  }
+  override def toString(): String = sbToString(buildString(_, TopScope))
 
+  def buildString(stop: NamespaceBinding): String = sbToString(buildString(_, stop))
   def buildString(sb: StringBuilder, stop: NamespaceBinding): Unit = {
     if (this ne stop) { // contains?
       sb.append(" xmlns")
diff --git a/src/library/scala/xml/PrettyPrinter.scala b/src/library/scala/xml/PrettyPrinter.scala
index 7e09d58c9b..c16e8a0da9 100644
--- a/src/library/scala/xml/PrettyPrinter.scala
+++ b/src/library/scala/xml/PrettyPrinter.scala
@@ -12,6 +12,7 @@
 package scala.xml
 
 import scala.collection.Map
+import Utility.sbToString
 
 /** Class for pretty printing. After instantiating, you can use the
  *  toPrettyXML methods to convert XML to a formatted string. The class
@@ -113,41 +114,43 @@ class PrettyPrinter( width:Int, step:Int ) {
    *  @return  ...
    */
   protected def leafTag(n: Node) = {
-    val sb = new StringBuilder("<")
-    n.nameToString(sb)
-    //Utility.appendPrefixedName( n.prefix, n.label, pmap, sb );
-    n.attributes.buildString(sb)
-    //Utility.attr2xml( n.scope, n.attributes, pmap, sb );
-    sb.append("/>")
-    sb.toString()
+    def mkLeaf(sb: StringBuilder) {
+      sb append '<'
+      n nameToString sb
+      n.attributes buildString sb
+      sb append "/>"
+    }
+    sbToString(mkLeaf)
   }
 
   protected def startTag(n: Node, pscope: NamespaceBinding): (String, Int) = {
-    val sb = new StringBuilder("<")
-    n.nameToString(sb) //Utility.appendPrefixedName( n.prefix, n.label, pmap, sb );
-    val i = sb.length + 1
-    n.attributes.buildString(sb)
-    n.scope.buildString(sb, pscope)
-    sb.append('>')
-    (sb.toString(), i)
+    var i = 0
+    def mkStart(sb: StringBuilder) {
+      sb append '<'
+      n nameToString sb
+      i = sb.length + 1
+      n.attributes buildString sb
+      n.scope.buildString(sb, pscope)
+      sb append '>'
+    }
+    (sbToString(mkStart), i)
   }
 
   protected def endTag(n: Node) = {
-    val sb = new StringBuilder("</")
-    n.nameToString(sb) //Utility.appendPrefixedName( n.prefix, n.label, pmap, sb );
-    sb.append('>')
-    sb.toString()
+    def mkEnd(sb: StringBuilder) {
+      sb append "</"
+      n nameToString sb
+      sb append '>'
+    }
+    sbToString(mkEnd)
   }
 
   protected def childrenAreLeaves(n: Node): Boolean = {
-    val it = n.child.elements
-    while (it.hasNext)
-      it.next match {
-        case _:Atom[_] | _:Comment | _:EntityRef | _:ProcInstr =>
-        case _:Node =>
-          return false
-      }
-    true
+    def isLeaf(l: Node) = l match {
+      case _:Atom[_] | _:Comment | _:EntityRef | _:ProcInstr  => true
+      case _                                                  => false
+    }
+    n.child forall isLeaf
   }
 
   protected def fits(test: String) =
@@ -268,11 +271,8 @@ class PrettyPrinter( width:Int, step:Int ) {
    *  @param pmap the namespace to prefix mapping
    *  @return     ...
    */
-  def format(n: Node, pscope: NamespaceBinding): String = {
-    val sb = new StringBuilder()
-    format(n, pscope, sb)
-    sb.toString()
-  }
+  def format(n: Node, pscope: NamespaceBinding): String =
+    sbToString(format(n, pscope, _))
 
   /** Returns a formatted string containing well-formed XML nodes with
    *  default namespace prefix mapping.
@@ -288,11 +288,8 @@ class PrettyPrinter( width:Int, step:Int ) {
    *  @param nodes the sequence of nodes to be serialized
    *  @param pmap  the namespace to prefix mapping
    */
-  def formatNodes(nodes: Seq[Node], pscope: NamespaceBinding): String = {
-    var sb = new StringBuilder()
-    formatNodes(nodes, pscope, sb)
-    sb.toString()
-  }
+  def formatNodes(nodes: Seq[Node], pscope: NamespaceBinding): String =
+    sbToString(formatNodes(nodes, pscope, _))
 
   /** Appends a formatted string containing well-formed XML with
    *  the given namespace to prefix mapping to the given stringbuffer.
diff --git a/src/library/scala/xml/Utility.scala b/src/library/scala/xml/Utility.scala
index 4d8f99fa9e..4b749db9e6 100644
--- a/src/library/scala/xml/Utility.scala
+++ b/src/library/scala/xml/Utility.scala
@@ -19,8 +19,15 @@ import collection.mutable.{Set, HashSet}
  *
  * @author Burak Emir
  */
-object Utility extends AnyRef with parsing.TokenTests {
-
+object Utility extends AnyRef with parsing.TokenTests
+{
+  // helper for the extremely oft-repeated sequence of creating a
+  // StringBuilder, passing it around, and then grabbing its String.
+  private [xml] def sbToString(f: (StringBuilder) => Unit): String = {
+    val sb = new StringBuilder
+    f(sb)
+    sb.toString
+  }
 
   /** trims an element - call this method, when you know that it is an
    *  element (and not a text node) so you know that it will not be trimmed
@@ -72,8 +79,7 @@ object Utility extends AnyRef with parsing.TokenTests {
    * @param text ...
    * @return     ...
    */
-  final def escape(text: String): String =
-    escape(text, new StringBuilder()).toString()
+  final def escape(text: String): String = sbToString(escape(text, _))
 
   /**
    * Appends escaped string to <code>s</code>.
@@ -168,12 +174,8 @@ object Utility extends AnyRef with parsing.TokenTests {
    *
    * @todo define a way to escape literal characters to &amp;xx; references
    */
-  def toXML(n: Node, stripComment: Boolean): String = {
-    val sb = new StringBuilder()
-    toXML(n, TopScope, sb, stripComment)
-    sb.toString()
-  }
-
+  def toXML(n: Node, stripComment: Boolean): String =
+    sbToString(toXML(n, TopScope, _, stripComment))
 
   /**
    * Appends a tree to the given stringbuffer within given namespace scope.
@@ -274,11 +276,7 @@ object Utility extends AnyRef with parsing.TokenTests {
     }
   )
 
-  def appendQuoted(s: String): String = {
-    val sb = new StringBuilder()
-    appendQuoted(s, sb)
-    sb.toString()
-  }
+  def appendQuoted(s: String): String = sbToString(appendQuoted(s, _))
 
   /**
    * Appends &quot;s&quot; if string <code>s</code> does not contain &quot;,
diff --git a/src/library/scala/xml/Xhtml.scala b/src/library/scala/xml/Xhtml.scala
index 1fe16c71b3..8438f91173 100644
--- a/src/library/scala/xml/Xhtml.scala
+++ b/src/library/scala/xml/Xhtml.scala
@@ -3,6 +3,7 @@
 package scala.xml
 
 import parsing.XhtmlEntities
+import Utility.sbToString
 
 /* (c) David Pollak  2007 WorldWide Conferencing, LLC */
 
@@ -21,11 +22,8 @@ object Xhtml
    *
    * @param nodeSeq   the node sequence
    */
-  def toXhtml(nodeSeq: NodeSeq): String = {
-    val sb = new StringBuilder
-    sequenceToXML(nodeSeq, TopScope, sb, false, false)
-    sb.toString
-  }
+  def toXhtml(nodeSeq: NodeSeq): String =
+    sbToString(sequenceToXML(nodeSeq, TopScope, _, false, false))
 
   /**
    * Convenience function: amounts to calling toXhtml(node, TopScope, ...)
@@ -33,11 +31,8 @@ object Xhtml
    *
    * @param nodeSeq   the node sequence
    */
-  def toXhtml(n: Node, stripComment: Boolean, convertAmp: Boolean): String = {
-    val sb = new StringBuilder()
-    toXhtml(n, TopScope, sb, stripComment, convertAmp)
-    sb.toString()
-  }
+  def toXhtml(n: Node, stripComment: Boolean, convertAmp: Boolean): String =
+    sbToString(toXhtml(n, TopScope, _, stripComment, convertAmp))
 
   /**
    * Appends a tree to the given stringbuffer within given namespace scope.
diff --git a/src/library/scala/xml/dtd/ContentModel.scala b/src/library/scala/xml/dtd/ContentModel.scala
index 013f3d0414..a1e2ea0aa5 100644
--- a/src/library/scala/xml/dtd/ContentModel.scala
+++ b/src/library/scala/xml/dtd/ContentModel.scala
@@ -13,6 +13,7 @@ package scala.xml.dtd
 
 import scala.util.regexp.WordExp
 import scala.util.automata.{DetWordAutom, SubsetConstruction, WordBerrySethi}
+import Utility.sbToString
 
 object ContentModel extends WordExp {
   type _labelT = ElemName
@@ -49,11 +50,7 @@ object ContentModel extends WordExp {
     return s
   }
 
-  def buildString(r: RegExp): String = {
-    val sb = new StringBuilder()
-    buildString(r, sb)
-    sb.toString()
-  }
+  def buildString(r: RegExp): String = sbToString(buildString(r, _))
 
   /* precond: rs.length >= 1 */
   private def buildString(rs: Seq[RegExp], sb: StringBuilder, sep: Char) {
@@ -95,11 +92,7 @@ object ContentModel extends WordExp {
 
 sealed abstract class ContentModel {
 
-  override def toString(): String = {
-    val sb = new StringBuilder()
-    buildString(sb)
-    sb.toString()
-  }
+  override def toString(): String = sbToString(buildString)
 
   def buildString(sb:StringBuilder): StringBuilder;
   /*
diff --git a/src/library/scala/xml/dtd/Decl.scala b/src/library/scala/xml/dtd/Decl.scala
index b94c56062b..50385c69a6 100644
--- a/src/library/scala/xml/dtd/Decl.scala
+++ b/src/library/scala/xml/dtd/Decl.scala
@@ -10,7 +10,7 @@
 
 
 package scala.xml.dtd
-
+import Utility.sbToString
 
 abstract class Decl
 
@@ -49,8 +49,7 @@ extends MarkupDecl with DtdTypeSymbol {
  *  directly.
  */
 case class AttrDecl(name: String, tpe: String, default: DefaultDecl) {
-  override def toString(): String =
-    buildString(new StringBuilder()).toString();
+  override def toString(): String = sbToString(buildString)
 
   def buildString(sb: StringBuilder): StringBuilder = {
     sb.append("  ").append(name).append(' ').append(tpe).append(' ');
@@ -157,9 +156,7 @@ case object IMPLIED extends DefaultDecl {
 }
 
 case class DEFAULT(fixed: Boolean, attValue: String) extends DefaultDecl {
-  override def toString(): String =
-    buildString(new StringBuilder()).toString();
-
+  override def toString(): String = sbToString(buildString)
   override def buildString(sb: StringBuilder): StringBuilder = {
     if (fixed) sb.append("#FIXED ")
     Utility.appendEscapedQuoted(attValue, sb)