Change the way hard splits are handled.

lib/src/line_splitting/solve_state.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.solve_state;
 
 import '../debug.dart' as debug;
 import '../rule/rule.dart';
 import '../whitespace.dart';
 import 'line_splitter.dart';
@@ skipping 95 matching lines @@
   /// states may diverge by binding unbound rules or not.
   Set<Rule> _boundRulesInUnboundLines;
 
   SolveState(this._splitter, this._ruleValues) {
     _calculateSplits();
     _calculateCost();
   }
 
   /// Gets the value to use for [rule], either the bound value or
   /// [Rule.unsplit] if it isn't bound.
-  int getValue(Rule rule) {
-    if (rule is HardSplitRule) return Rule.unsplit;
-
-    return _ruleValues.getValue(rule);
-  }
+  int getValue(Rule rule) => _ruleValues.getValue(rule);
 
   /// Returns `true` if this state is a better solution to use as the final
   /// result than [other].
   bool isBetterThan(SolveState other) {
     // If this state contains an unbound rule that we know can't be left
     // unsplit, we can't pick this as a solution.
     if (!_isComplete) return false;
 
     // Anything is better than nothing.
     if (other == null) return true;
@@ skipping 299 matching lines @@
 
     _splits.setCost(cost);
   }
 
   /// Adds [rule] and all of the rules it constrains to the set of [_liveRules].
   ///
   /// Only does this if [rule] is a valid soft rule. Returns `true` if any new
   /// live rules were added.
   bool _addLiveRules(Rule rule) {
     if (rule == null) return false;
-    if (rule is HardSplitRule) return false;
 
     var added = false;
     for (var constrained in rule.allConstrainedRules) {
       if (_ruleValues.contains(constrained)) continue;
 
       _liveRules.add(constrained);
       added = true;
     }
 
     return added;
@@ skipping 14 matching lines @@
 
     for (var i = 0; i < _splitter.chunks.length - 1; i++) {
       if (splits.shouldSplitAt(i)) {
         if (hasUnbound) _boundRulesInUnboundLines.addAll(boundInLine);
 
         boundInLine.clear();
         hasUnbound = false;
       }
 
       var rule = _splitter.chunks[i].rule;
-      if (rule != null && rule is! HardSplitRule) {
+      if (rule != null) {
         if (_ruleValues.contains(rule)) {
           boundInLine.add(rule);
         } else {
           hasUnbound = true;
         }
       }
     }
 
     if (hasUnbound) _boundRulesInUnboundLines.addAll(boundInLine);
   }
@@ skipping 104 matching lines @@
 
     buffer.write("   \$${splits.cost}");
 
     if (overflowChars > 0) buffer.write(" (${overflowChars} over)");
     if (!_isComplete) buffer.write(" (incomplete)");
     if (splits == null) buffer.write(" invalid");
 
     return buffer.toString();
   }
 }