Move client/{base, observable, layout, touch, util, view} to samples/ui_lib .

client/util/CollectionUtils.dart

-// Copyright (c) 2011, 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.
-
-typedef num NumericValueSelector<T>(T value);
-
-/**
- * General purpose collection utilities.
- * TODO(jmesserly): make these top level functions?
- */
-class CollectionUtils {
-
-  static void insertAt(List arr, int pos, value) {
-    assert (pos >= 0);
-    assert (pos <= arr.length);
-
-    if (pos == arr.length) {
-      arr.add(value);
-    } else {
-      // TODO(sigmund): replace this push with a call that ensures capacity
-      // (currently not supported in the JS implementation of list). E.g.
-      // [: arr.length = arr.length + 1; :]
-      arr.add(null);
-
-      // shift elements from [pos] (note: arr already has null @ length - 1)
-      for (int i = arr.length - 2; i >= pos; i--) {
-        arr[i + 1] = arr[i];
-      }
-      arr[pos] = value;
-
-      // TODO(jmesserly): we won't need to do this once List
-      // implements insertAt
-      if (arr is ObservableList) {
-        // TODO(jmesserly): shouldn't need to cast after testing instanceof
-        ObservableList obs = arr;
-        obs.recordListInsert(pos, value);
-      }
-    }
-  }
-
-  // Collection<T> supports most of the ES 5 list methods, but it's missing
-  // map.
-
-  // TODO(jmesserly): we might want a version of this that return an iterable,
-  // however JS, Python and Ruby versions are all eager.
-  static List map(Iterable source, var mapper) {
-    // TODO(jmesserly): I was trying to set the capacity here, but instead it
-    // seems to create a fixed list. Hence assigning by index below.
-    List result = new List(source is List ? source.dynamic.length : null);
-    int i = 0;
-    for (final item in source) {
-      result[i++] = mapper(item);
-    }
-    return result;
-  }
-
-  /**
-   * Finds the item in [source] that matches [test].  Returns null if
-   * no item matches.  The typing should be:
-   * T find(Iterable<T> source, bool test(T item)), but we don't have generic
-   * functions.
-   */
-  static find(Iterable source, bool test(item)) {
-    for (final item in source) {
-      if (test(item)) return item;
-    }
-
-    return null;
-  }
-
-  /** Compute the minimum of an iterable. Returns null if empty. */
-  static num min(Iterable source) {
-    final iter = source.iterator();
-    if (!iter.hasNext()) {
-      return null;
-    }
-    num best = iter.next();
-    while (iter.hasNext()) {
-      best = Math.min(best, iter.next());
-    }
-    return best;
-  }
-
-  /** Compute the maximum of an iterable. Returns null if empty. */
-  static num max(Iterable source) {
-    final iter = source.iterator();
-    if (!iter.hasNext()) {
-      return null;
-    }
-    num best = iter.next();
-    while (iter.hasNext()) {
-      best = Math.max(best, iter.next());
-    }
-    return best;
-  }
-
-  /** Orders an iterable by its values, or by a key selector. */
-  static List orderBy(Iterable source, [NumericValueSelector selector = null]) {
-    final result = new List.from(source);
-    sortBy(result, selector);
-    return result;
-  }
-
-  /** Sorts a list by its values, or by a key selector. */
-  // TODO(jmesserly): we probably don't want to call the key selector more than
-  // once for a given element. This would improve performance and the API
-  // contract could be stronger.
-  static void sortBy(List list, [NumericValueSelector selector = null]) {
-    if (selector != null) {
-      list.sort((x, y) => selector(x) - selector(y));
-    } else {
-      list.sort((x, y) => x - y);
-    }
-  }
-
-  /** Compute the sum of an iterable. An empty iterable is an error. */
-  static num sum(Iterable source, [NumericValueSelector selector = null]) {
-    final iter = source.iterator();
-    num total = 0;
-    if (selector != null) {
-      do {
-        total += selector(iter.next());
-      } while (iter.hasNext());
-    } else {
-      do {
-        total += iter.next();
-      } while (iter.hasNext());
-    }
-    return total;
-  }
-
-  // TODO(jmesserly): something like should exist on Map, either a method or a
-  // constructor, see bug #5340679
-  static void copyMap(Map dest, Map source) {
-    for (final k in source.getKeys()) {
-      dest[k] = source[k];
-    }
-  }
-}