Tokenize one line at a time.

dart/site/try/src/interaction_manager.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 trydart.interaction_manager;
 
 import 'dart:html';
 
 import 'dart:convert' show
     JSON;
@@ skipping 225 matching lines @@
     trySelection.updateText(currentText);
 
     context.currentCompilationUnit.content = currentText;
 
     editor.seenIdentifiers = new Set<String>.from(mock.identifiers);
 
     editor.isMalformedInput = false;
     int offset = 0;
     List<Node> nodes = <Node>[];
 
-    tokenizeAndHighlight(currentText, offset, trySelection, nodes);
+    int lineNumber = 1;

[kasperl, 2014/04/07 04:54:25]

If you have to keep an index anyway, maybe it would be cleaner to introduce a
local variable for the List that's the result of the split and run from zero to
its length?

At least you should be updating lineNumber...

[ahe, 2014/04/07 09:38:29]

Variable not needed. Line numbers implemented using CSS only.

+    for (String line in currentText.split('\n')) {
+      List<Node> lineNodes = <Node>[];
+      tokenizeAndHighlight(line, offset, trySelection, lineNodes);
+      offset += line.length + 1; // + 1 for newline.
+      nodes.add(new SpanElement()
+          ..nodes.addAll(lineNodes)
+          ..classes.add('lineNumber'));
+    }
 
     mainEditorPane
         ..nodes.clear()
         ..nodes.addAll(nodes);
     trySelection.adjust(selection);
 
     // Discard highlighting mutations.
     observer.takeRecords();
   }
 
@@ skipping 406 matching lines @@
       event.getModifierState("NumLock") ||
       event.getModifierState("ScrollLock") ||
       event.getModifierState("Scroll") ||
       event.getModifierState("Win") ||
       event.getModifierState("Shift") ||
       event.getModifierState("SymbolLock") ||
       event.getModifierState("OS");
 }
 
 void tokenizeAndHighlight(String currentText,
-                          int offset,
+                          int start,
                           TrySelection trySelection,
                           List<Node> nodes) {
+  int offset = 0;
   //   + offset  + charOffset  + globalOffset   + (charOffset + charCount)
   //   v         v             v                v
   // do          identifier_abcdefghijklmnopqrst
   for (Token token = tokenize(currentText);
        token.kind != EOF_TOKEN;
        token = token.next) {
     int charOffset = token.charOffset;
     int charCount = token.charCount;
 
     if (charOffset < offset) continue; // Happens for scanner errors.
 
     Decoration decoration = editor.getDecoration(token);
     if (decoration == null) continue;
 
     // Add a node for text before current token.
-    trySelection.addNodeFromSubstring(offset, charOffset, nodes);
+    trySelection.addNodeFromSubstring(start + offset, start + charOffset, nodes);

[kasperl, 2014/04/07 04:54:25]

Long line.

[ahe, 2014/04/07 09:38:29]

Done.

 
     // Add a node for current token.
     trySelection.addNodeFromSubstring(
-        charOffset, charOffset + charCount, nodes, decoration);
+        start + charOffset, start + charOffset + charCount, nodes, decoration);
 
     offset = charOffset + charCount;
   }
 
   // Add a node for anything after the last (decorated) token.
-  trySelection.addNodeFromSubstring(offset, currentText.length, nodes);
+  trySelection.addNodeFromSubstring(start + offset, start + currentText.length, nodes);

[kasperl, 2014/04/07 04:54:25]

Long line.

[ahe, 2014/04/07 09:38:29]

Done.

 
   // Ensure text always ends with a newline.
   if (!currentText.endsWith('\n')) {
     nodes.add(new Text('\n'));
   }
 }
 
 void normalizeMutationRecord(MutationRecord record, TrySelection selection) {
   if (record.addedNodes.isEmpty) return;
   for (Node node in record.addedNodes) {
     if (node.parent == null) continue;
     StringBuffer buffer = new StringBuffer();
     int selectionOffset = htmlToText(node, buffer, selection);
     Text newNode = new Text('$buffer');
     node.replaceWith(newNode);
     if (selectionOffset != -1) {
       selection.anchorNode = newNode;
       selection.anchorOffset = selectionOffset;
     }
   }
 }