Create string efficiently from Uint16List/View.

sdk/lib/core/errors.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.core;
 
 /**
  * Error objects thrown in the case of a program failure.
  *
  * An `Error` object represents a program failure that the programmer
@@ skipping 279 matching lines @@
    *
    * Throws if the range is not valid for an indexable object with
    * the given [length].
    * A range is valid for an indexable object with a given [length]
    *
    * if `0 <= [start] <= [end] <= [length]`.
    * An `end` of `null` is considered equivalent to `length`.
    *
    * The [startName] and [endName] defaults to `"start"` and `"end"`,
    * respectively.
+   *
+   * Returns the actual `end` value, which is `length` if `end` is `null`,
+   * and `end` otherwise.
    */
-  static void checkValidRange(int start, int end, int length,
+  static int checkValidRange(int start, int end, int length,
                               [String startName, String endName,
                                String message]) {
     if (start < 0 || start > length) {
       if (startName == null) startName = "start";
       throw new RangeError.range(start, 0, length, startName, message);
     }
-    if (end != null && (end < start || end > length)) {
-      if (endName == null) endName = "end";
-      throw new RangeError.range(end, start, length, endName, message);
+    if (end != null) {
+      if (end < start || end > length) {
+        if (endName == null) endName = "end";
+        throw new RangeError.range(end, start, length, endName, message);
+      }
+      return end;
     }
+    return length;
   }
 
   /**
    * Check that an integer value isn't negative.
    *
    * Throws if the value is negative.
    */
   static void checkNotNegative(int value, [String name, String message]) {
     if (value < 0) throw new RangeError.range(value, 0, null, name, message);
   }
@@ skipping 226 matching lines @@
  * the first time it is read. If evaluating the initializer expression causes
  * another read of the variable, this error is thrown.
  */
 class CyclicInitializationError extends Error {
   final String variableName;
   CyclicInitializationError([this.variableName]);
   String toString() => variableName == null
       ? "Reading static variable during its initialization"
       : "Reading static variable '$variableName' during its initialization";
 }