New, simpler and faster line splitter.

lib/src/debug.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.
 
 /// Internal debugging utilities.
 library dart_style.src.debug;
 
 import 'dart:math' as math;
 
 import 'chunk.dart';
-import 'line_prefix.dart';
-import 'line_splitter.dart';
+import 'rule/rule.dart';
+import 'rule_set.dart';
 
 /// Set this to `true` to turn on diagnostic output while building chunks.
 bool traceChunkBuilder = false;
 
 /// Set this to `true` to turn on diagnostic output while writing lines.
 bool traceLineWriter = false;
 
 /// Set this to `true` to turn on diagnostic output while line splitting.
 bool traceSplitter = false;
 
@@ skipping 54 matching lines @@
       spans.addAll(chunk.spans);
 
       addSpans(chunk.blockChunks);
     }
   }
 
   addSpans(chunks);
 
   spans = spans.toList();
 
+  var rules = chunks
+      .map((chunk) => chunk.rule)
+      .where((rule) => rule != null && rule is! HardSplitRule)
+      .toSet();
+
   var rows = [];
 
   addChunk(chunk, prefix, index) {
     var row = [];
     row.add("$prefix$index:");
 
     if (chunk.text.length > 70) {
       row.add(chunk.text.substring(0, 70));
     } else {
       row.add(chunk.text);
     }
 
     var spanBars = "";
     for (var span in spans) {
       spanBars += chunk.spans.contains(span) ? "|" : " ";
     }
     row.add(spanBars);
 
     writeIf(predicate, String callback()) {
       if (predicate) {
         row.add(callback());
       } else {
         row.add("");
       }
     }
 
     if (chunk.rule != null) {
       row.add(chunk.isHardSplit ? "" : chunk.rule.toString());
 
-      writeIf(chunk.rule.outerRules.isNotEmpty,
-          () => "-> ${chunk.rule.outerRules.join(" ")}");
+      var outerRules = chunk.rule.outerRules.toSet().intersection(rules);
+      writeIf(outerRules.isNotEmpty, () => "-> ${outerRules.join(" ")}");
     } else {
       row.add("(no rule)");
 
       // Outer rules.
       row.add("");
     }
 
     writeIf(chunk.indent != null && chunk.indent != 0,
         () => "indent ${chunk.indent}");
 
@@ skipping 36 matching lines @@
     buffer.writeln();
   }
 
   print(buffer.toString());
 }
 
 /// Convert the line to a [String] representation.
 ///
 /// It will determine how best to split it into multiple lines of output and
 /// return a single string that may contain one or more newline characters.
-void dumpLines(List<Chunk> chunks, LinePrefix prefix, SplitSet splits) {
+void dumpLines(List<Chunk> chunks, int firstLineIndent, SplitSet splits) {
   var buffer = new StringBuffer();
 
-  // TODO(rnystrom): Handle block chunks here.
+  writeIndent(indent) => buffer.write(gray("| " * (indent ~/ 2)));
 
-  writeIndent(indent) => buffer.write(gray("| " * (indent ~/ 2)));
-  writeIndent(prefix.column);
+  writeChunksUnsplit(List<Chunk> chunks) {
+    for (var chunk in chunks) {
+      buffer.write(chunk.text);
+      if (chunk.spaceWhenUnsplit) buffer.write(" ");
 
-  for (var i = prefix.length; i < chunks.length - 1; i++) {
+      // Recurse into the block.
+      writeChunksUnsplit(chunk.blockChunks);
+    }
+  }
+
+  writeIndent(firstLineIndent);
+
+  for (var i = 0; i < chunks.length - 1; i++) {
     var chunk = chunks[i];
     buffer.write(chunk.text);
 
     if (splits.shouldSplitAt(i)) {
       for (var j = 0; j < (chunk.isDouble ? 2 : 1); j++) {
         buffer.writeln();
         writeIndent(splits.getColumn(i));
       }
     } else {
+      writeChunksUnsplit(chunk.blockChunks);
+
       if (chunk.spaceWhenUnsplit) buffer.write(" ");
     }
   }
 
   buffer.write(chunks.last.text);
   log(buffer);
 }
 
 String _color(String ansiEscape) => useAnsiColors ? ansiEscape : "";