- Remove unnecessary is-check.

runtime/lib/growable_array.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.
 
 class _GrowableList<T> implements List<T> {
   static final int _classId = (new _GrowableList(0))._cid;
 
   void insert(int index, T element) {
     if (index < 0 || index > length) {
       throw new RangeError.range(index, 0, length);
     }
     if (index == this.length) {
       add(element);
       return;
     }
     int oldLength = this.length;
     // We are modifying the length just below the is-check. Without the check
     // Array.copy could throw an exception, leaving the list in a bad state
     // (with a length that has been increased, but without a new element).
     if (index is! int) throw new ArgumentError(index);
     this.length++;
-    Lists.copy(this,
-                index,
-                this,
-                index + 1,
-                oldLength - index);
+    Lists.copy(this, index, this, index + 1, oldLength - index);
     this[index] = element;
   }
 
   T removeAt(int index) {
-    if (index is! int) throw new ArgumentError(index);
-    T result = this[index];
+    var result = this[index];
     int newLength = this.length - 1;
-    Lists.copy(this,
-                index + 1,
-                this,
-                index,
-                newLength - index);
+    Lists.copy(this, index + 1, this, index, newLength - index);
     this.length = newLength;
     return result;
   }
 
   bool remove(Object element) {
     for (int i = 0; i < this.length; i++) {
       if (this[i] == element) {
         removeAt(i);
         return true;
       }
@@ skipping 40 matching lines @@
   Iterable<T> getRange(int start, int end) {
     return IterableMixinWorkaround.getRangeList(this, start, end);
   }
 
   void setRange(int start, int end, Iterable<T> iterable, [int skipCount = 0]) {
     IterableMixinWorkaround.setRangeList(this, start, end, iterable, skipCount);
   }
 
   void removeRange(int start, int end) {
     Lists.indicesCheck(this, start, end);
-    Lists.copy(this,
-                end,
-                this,
-                start,
-                this.length - end);
+    Lists.copy(this, end, this, start, this.length - end);
     this.length = this.length - (end - start);
   }
 
   void replaceRange(int start, int end, Iterable<T> iterable) {
     IterableMixinWorkaround.replaceRangeList(this, start, end, iterable);
   }
 
   void fillRange(int start, int end, [T fillValue]) {
     IterableMixinWorkaround.fillRangeList(this, start, end, fillValue);
   }
@@ skipping 239 matching lines @@
   }
 
   Set<T> toSet() {
     return new Set<T>.from(this);
   }
 
   Map<int, T> asMap() {
     return IterableMixinWorkaround.asMapList(this);
   }
 }