Optimize splitting lines with many rules.

lib/src/line_splitting/rule_set.dart

 // Copyright (c) 2015, 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 dart_style.src.line_splitting.rule_set;
 
 import '../rule/rule.dart';
 
 /// An optimized data structure for storing a set of values for some rules.
 ///
@@ skipping 41 matching lines @@
   ///
   /// Returns `true` if all constraints between the bound rules are valid. Even
   /// if not, this still modifies the [RuleSet].
   ///
   /// If an unbound rule gets constrained to `-1` (meaning it must split, but
   /// can split any way it wants), invokes [onSplitRule] with it.
   bool tryBind(List<Rule> rules, Rule rule, int value, onSplitRule(Rule rule)) {
     _values[rule.index] = value;
 
     // Test this rule against the other rules being bound.
-    for (var other in rules) {
-      if (rule == other) continue;
-
+    for (var other in rule.constrainedRules) {
       var otherValue = _values[other.index];
       var constraint = rule.constrain(value, other);
 
       if (otherValue == null) {
         // The other rule is unbound, so see if we can constrain it eagerly to
         // a value now.
         if (constraint == -1) {
           // If we know the rule has to split and there's only one way it can,
           // just bind that.
           if (other.numValues == 2) {
@@ skipping 73 matching lines @@
     var result = [];
     for (var i = 0; i < _columns.length; i++) {
       if (_columns[i] != null) {
         result.add("$i:${_columns[i]}");
       }
     }
 
     return result.join(" ");
   }
 }