fixed tickets 152, 123.

spreadsheet demo crash. Made Lists more tail recursive. toString in
Sets and Maps now says just Set(...) or Map(...) without revealing the
implementation.

5 files changed, 40 insertions, 12 deletions

diff --git a/src/library/scala/List.scala b/src/library/scala/List.scala
index 38028b7385..537f649a8a 100644
--- a/src/library/scala/List.scala
+++ b/src/library/scala/List.scala
@@ -456,9 +456,14 @@ sealed abstract class List[+A] extends Seq[A] {
    *  @param prefix the prefix to reverse and then prepend
    *  @return       the concatenation of the reversed prefix and the current list.
    */
-  def reverse_:::[B >: A](prefix: List[B]): List[B] = prefix match {
-    case Nil => this
-    case head :: tail => (head :: this).reverse_:::(tail)
+  def reverse_:::[B >: A](prefix: List[B]): List[B] = {
+    var these: List[B] = this
+    var pres = prefix
+    while (!pres.isEmpty) {
+      these = pres.head :: these
+      pres = pres.tail
+    }
+    these
   }
 
   /** Returns the number of elements in the list.
@@ -540,8 +545,15 @@ sealed abstract class List[+A] extends Seq[A] {
    */
   override def last: A =
     if (isEmpty) throw new Predef.NoSuchElementException("Nil.last")
-    else if (tail.isEmpty) head
-    else tail.last
+    else {
+      var cur = this
+      var next = this.tail
+      while (!next.isEmpty) {
+        cur = next
+        next = next.tail
+      }
+      cur.head
+    }
 
   /** Returns the <code>n</code> first elements of this list, or else the whole
    *  list, if it has less than <code>n</code> elements.
@@ -580,9 +592,15 @@ sealed abstract class List[+A] extends Seq[A] {
    *  @param n the number of elements to drop.
    *  @return the list without its <code>n</code> first elements.
    */
-  override def drop(n: Int): List[A] =
-    if (isEmpty || n <= 0) this
-    else (tail drop (n-1))
+  override def drop(n: Int): List[A] = {
+    var these = this
+    var count = n
+    while (!these.isEmpty && count > 0) {
+      these = these.tail
+      count -= 1
+    }
+    these
+  }
 
   /** Returns the rightmost <code>n</code> elements from this list.
    *
diff --git a/src/library/scala/Responder.scala b/src/library/scala/Responder.scala
index 9aade29aa1..fd7e5f1b35 100644
--- a/src/library/scala/Responder.scala
+++ b/src/library/scala/Responder.scala
@@ -12,6 +12,7 @@ package scala
 
 /** This object contains utility methods to build responders.
  *
+ *  @author Martin Odersky
  *  @author Burak Emir
  *  @version 1.0
  *
@@ -60,6 +61,7 @@ object Responder {
  *  Scala while giving the impression that programs in these DSLs are
  *  written in direct style.
  *
+ *  @author Martin Odersky
  *  @author Burak Emir
  *  @version 1.0
  */
diff --git a/src/library/scala/collection/Map.scala b/src/library/scala/collection/Map.scala
index 015bda5f21..fafdf8e175 100644
--- a/src/library/scala/collection/Map.scala
+++ b/src/library/scala/collection/Map.scala
@@ -191,4 +191,8 @@ trait Map[A, +B] extends PartialFunction[A, B] with Collection[(A, B)] {
     override def contains(key : A) = Map.this.contains(key)
     override def get(key : A) = Map.this.get(key).map(f)
   }
+
+  /** Defines the prefix of this object's <code>toString</code> representation.
+   */
+  override protected def stringPrefix : String = "Map"
 }
diff --git a/src/library/scala/collection/Set.scala b/src/library/scala/collection/Set.scala
index 4f412712d6..aac1342a37 100644
--- a/src/library/scala/collection/Set.scala
+++ b/src/library/scala/collection/Set.scala
@@ -124,4 +124,8 @@ trait Set[A] extends (A => Boolean) with Collection[A] {
     copyToArray(result, 0)
     result
   }
+
+  /** Defines the prefix of this object's <code>toString</code> representation.
+   */
+  override protected def stringPrefix : String = "Set"
 }
diff --git a/src/library/scala/util/parsing/combinator1/lexical/StdLexical.scala b/src/library/scala/util/parsing/combinator1/lexical/StdLexical.scala
index fc04116692..e278869f7a 100644
--- a/src/library/scala/util/parsing/combinator1/lexical/StdLexical.scala
+++ b/src/library/scala/util/parsing/combinator1/lexical/StdLexical.scala
@@ -37,9 +37,9 @@ class StdLexical extends Lexical with StdTokens {
   def token: Parser[Token] =
     ( letter ~ rep( letter | digit )                    ^^ { case first ~ rest => processIdent(first :: rest mkString "") }
     | digit ~ rep( digit )                              ^^ { case first ~ rest => NumericLit(first :: rest mkString "") }
-    | '\'' ~ rep( chrExcept('\'', '\n', EofCh) ) ~ '\'' ^^ { case _ ~ chars ~ _ => StringLit(chars mkString "") }
-    | '\"' ~ rep( chrExcept('\"', '\n', EofCh) ) ~ '\"' ^^ { case _ ~ chars ~ _ => StringLit(chars mkString "") }
-    | EofCh                                             ^^ const(EOF)
+    | '\'' ~ rep( chrExcept('\'', '\n', EofCh) ) ~ '\'' ^^ { case '\'' ~ chars ~ '\'' => StringLit(chars mkString "") }
+    | '\"' ~ rep( chrExcept('\"', '\n', EofCh) ) ~ '\"' ^^ { case '\"' ~ chars ~ '\"' => StringLit(chars mkString "") }
+    | EofCh                                             ^^^ EOF
     | '\'' ~> failure("unclosed string literal")
     | '\"' ~> failure("unclosed string literal")
     | delim
@@ -70,7 +70,7 @@ class StdLexical extends Lexical with StdTokens {
 
   private var _delim: Parser[Token] = null
   protected def delim: Parser[Token] = {
-    if(_delim eq null) { // construct parser for delimiters by |'ing together the parsers for the individual delimiters,
+    if (_delim eq null) { // construct parser for delimiters by |'ing together the parsers for the individual delimiters,
     // starting with the longest one (hence the sort + reverse) -- otherwise a delimiter D will never be matched if
     // there is another delimiter that is a prefix of D
       def parseDelim(s: String): Parser[Token] = accept(s.toList) ^^ { x => Keyword(s) }