Compute covering offsets/lengths.

pkg/analysis_server/lib/src/services/correction/strings.dart

 // Copyright (c) 2014, 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.
 
 library services.src.correction.strings;
 
 import 'dart:math';
 
 /**
  * "$"
@@ skipping 23 matching lines @@
   }
   if (a == null) {
     return 1;
   }
   if (b == null) {
     return -1;
   }
   return a.compareTo(b);
 }
 
+int countLeadingWhitespaces(String str) {
+  int i = 0;
+  for (; i < str.length; i++) {
+    int c = str.codeUnitAt(i);
+    if (!isWhitespace(c)) {
+      break;
+    }
+  }
+  return i;
+}
+
 /**
  * Counts how many times [sub] appears in [str].
  */
 int countMatches(String str, String sub) {
   if (isEmpty(str) || isEmpty(sub)) {
     return 0;
   }
   int count = 0;
   int idx = 0;
   while ((idx = str.indexOf(sub, idx)) != -1) {
     count++;
     idx += sub.length;
   }
   return count;
 }
 
+int countTrailingWhitespaces(String str) {
+  int i = 0;
+  for (; i < str.length; i++) {
+    int c = str.codeUnitAt(str.length - 1 - i);
+    if (!isWhitespace(c)) {
+      break;
+    }
+  }
+  return i;
+}
+
 /**
  * Returns the number of characters common to the end of [a] and the start
  * of [b].
  */
 int findCommonOverlap(String a, String b) {
   int a_length = a.length;
   int b_length = b.length;
   // all empty
   if (a_length == 0 || b_length == 0) {
     return 0;
@@ skipping 176 matching lines @@
   }
   if (isEmpty(separator)) {
     return '';
   }
   int pos = str.lastIndexOf(separator);
   if (pos == -1) {
     return str;
   }
   return str.substring(pos + separator.length);
 }