Big merge from experimental to bleeding edge.

sdk/lib/collection/collections.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.collection;
 
 /**
  * The [Collections] class implements static methods useful when
  * writing a class that implements [Collection] and the [iterator]
  * method.
  */
 class Collections {
   static bool contains(Iterable iterable, var element) {
     for (final e in iterable) {
       if (element == e) return true;
     }
     return false;
   }
 
   static void forEach(Iterable iterable, void f(o)) {
     for (final e in iterable) {
       f(e);
     }
   }
 
-  static bool some(Iterable iterable, bool f(o)) {
+  static bool any(Iterable iterable, bool f(o)) {
     for (final e in iterable) {
       if (f(e)) return true;
     }
     return false;
   }
 
   static bool every(Iterable iterable, bool f(o)) {
     for (final e in iterable) {
       if (!f(e)) return false;
     }
     return true;
   }
 
-  static List map(Iterable source, List destination, f(o)) {
-    for (final e in source) {
-      destination.add(f(e));
-    }
-    return destination;
-  }
-
   static dynamic reduce(Iterable iterable,
                         dynamic initialValue,
                         dynamic combine(dynamic previousValue, element)) {
     for (final element in iterable) {
       initialValue = combine(initialValue, element);
     }
     return initialValue;
   }
 
-  static List filter(Iterable source, List destination, bool f(o)) {
-    for (final e in source) {
-      if (f(e)) destination.add(e);
-    }
-    return destination;
+  static bool isEmpty(Iterable iterable) {
+    return !iterable.iterator.moveNext();
   }
 
-  static bool isEmpty(Iterable iterable) {
-    return !iterable.iterator().hasNext;
+  static dynamic first(Iterable iterable) {
+    Iterator it = iterable.iterator;
+    if (!it.moveNext()) {
+      throw new StateError("No elements");
+    }
+    return it.current;
+  }
+
+  static dynamic last(Iterable iterable) {
+    Iterator it = iterable.iterator;
+    if (!it.moveNext()) {
+      throw new StateError("No elements");
+    }
+    dynamic result;
+    do {
+      result = it.current;
+    } while(it.moveNext());
+    return result;
+  }
+
+  static dynamic min(Iterable iterable, [int compare(var a, var b)]) {
+    if (compare == null) compare = Comparable.compare;
+    Iterator it = iterable.iterator;
+    if (!it.moveNext()) {
+      return null;
+    }
+    var min = it.current;
+    while (it.moveNext()) {
+      if (compare(min, it.current) > 0) min = it.current;
+    }
+    return min;
+  }
+
+  static dynamic max(Iterable iterable, [int compare(var a, var b)]) {
+    if (compare == null) compare = Comparable.compare;
+    Iterator it = iterable.iterator;
+    if (!it.moveNext()) {
+      return null;
+    }
+    var max = it.current;
+    while (it.moveNext()) {
+      if (compare(max, it.current) < 0) max = it.current;
+    }
+    return max;
+  }
+
+  static dynamic single(Iterable iterable) {
+    Iterator it = iterable.iterator;
+    if (!it.moveNext()) throw new StateError("No elements");
+    dynamic result = it.current;
+    if (it.moveNext()) throw new StateError("More than one element");
+    return result;
+  }
+
+  static dynamic firstMatching(Iterable iterable,
+                               bool test(dynamic value),
+                               dynamic orElse()) {
+    for (dynamic element in iterable) {
+      if (test(element)) return element;
+    }
+    if (orElse != null) return orElse();
+    throw new StateError("No matching element");
+  }
+
+  static dynamic lastMatching(Iterable iterable,
+                              bool test(dynamic value),
+                              dynamic orElse()) {
+    dynamic result = null;
+    bool foundMatching = false;
+    for (dynamic element in iterable) {
+      if (test(element)) {
+        result = element;
+        foundMatching = true;
+      }
+    }
+    if (foundMatching) return result;
+    if (orElse != null) return orElse();
+    throw new StateError("No matching element");
+  }
+
+  static dynamic lastMatchingInList(List list,
+                                    bool test(dynamic value),
+                                    dynamic orElse()) {
+    // TODO(floitsch): check that arguments are of correct type?
+    for (int i = list.length - 1; i >= 0; i--) {
+      dynamic element = list[i];
+      if (test(element)) return element;
+    }
+    if (orElse != null) return orElse();
+    throw new StateError("No matching element");
+  }
+
+  static dynamic singleMatching(Iterable iterable, bool test(dynamic value)) {
+    dynamic result = null;
+    bool foundMatching = false;
+    for (dynamic element in iterable) {
+      if (test(element)) {
+        if (foundMatching) {
+          throw new StateError("More than one matching element");
+        }
+        result = element;
+        foundMatching = true;
+      }
+    }
+    if (foundMatching) return result;
+    throw new StateError("No matching element");
+  }
+
+  static dynamic elementAt(Iterable iterable, int index) {
+    if (index is! int || index < 0) throw new RangeError.value(index);
+    int remaining = index;
+    for (dynamic element in iterable) {
+      if (remaining == 0) return element;
+      remaining--;
+    }
+    throw new RangeError.value(index);
+  }
+
+  static String join(Iterable iterable, [String separator]) {
+    Iterator iterator = iterable.iterator;
+    if (!iterator.moveNext()) return "";
+    StringBuffer buffer = new StringBuffer();
+    if (separator == null || separator == "") {
+      do {
+        buffer.add("${iterator.current}");
+      } while (iterator.moveNext());
+    } else {
+      buffer.add("${iterator.current}");
+      while (iterator.moveNext()) {
+        buffer.add(separator);
+        buffer.add("${iterator.current}");
+      }
+    }
+    return buffer.toString();
+  }
+
+  static String joinList(List<Object> list, [String separator]) {
+    if (list.isEmpty) return "";
+    if (list.length == 1) return "${list[0]}";
+    StringBuffer buffer = new StringBuffer();
+    if (separator == null || separator == "") {
+      for (int i = 0; i < list.length; i++) {
+        buffer.add("${list[i]}");
+      }
+    } else {
+      buffer.add("${list[0]}");
+      for (int i = 1; i < list.length; i++) {
+        buffer.add(separator);
+        buffer.add("${list[i]}");
+      }
+    }
+    return buffer.toString();
   }
 
   // TODO(jjb): visiting list should be an identityHashSet when it exists
 
   /**
    * Returns a string representing the specified collection. If the
    * collection is a [List], the returned string looks like this:
    * [:'[element0, element1, ... elementN]':]. The value returned by its
    * [toString] method is used to represent each element. If the specified
    * collection is not a list, the returned string looks like this:
@@ skipping 82 matching lines @@
    * Returns true if the specified collection contains the specified object
    * reference.
    */
   static _containsRef(Collection c, Object ref) {
     for (var e in c) {
       if (identical(e, ref)) return true;
     }
     return false;
   }
 }