"Reverting 30019" (aka reverting the revert)

pkg/docgen/lib/docgen.dart

Index: pkg/docgen/lib/docgen.dart
diff --git a/pkg/docgen/lib/docgen.dart b/pkg/docgen/lib/docgen.dart
index 701838266be9642c85573ecec32457fa976b4451..eab989360db73bf5b7ae46f65d24d6155a37f1ce 100644
--- a/pkg/docgen/lib/docgen.dart
+++ b/pkg/docgen/lib/docgen.dart
@@ -520,26 +520,113 @@ String _htmlMdn(String content, String url) {
       '<a href="' + url.trim() + '">from Mdn</a></p></div>';
 }
 
-/// Converts all [foo] references in comments to <a>libraryName.foo</a>.
-markdown.Node fixReference(String name, LibraryMirror currentLibrary,
+/// Look for the specified name starting with the current member, and
+/// progressively working outward to the current library scope.
+String findElementInScope(String name, LibraryMirror currentLibrary,
     ClassMirror currentClass, MemberMirror currentMember) {
-  var reference;
   var memberScope = currentMember == null ?
       null : currentMember.lookupInScope(name);
   if (memberScope != null) {
-    reference = docName(memberScope);
+    return docName(memberScope);
   } else {
     var classScope = currentClass == null ?
         null : currentClass.lookupInScope(name);
     if (classScope != null) {
-      reference = docName(classScope);
+      return docName(classScope);
     } else {
       var libraryScope = currentLibrary == null ?
           null : currentLibrary.lookupInScope(name);
-      reference = libraryScope != null ? docName(libraryScope) : name;
+      if (libraryScope != null) {
+        return docName(libraryScope);
+      }
+    }
+  }
+  return null;
+}
+
+// HTML escaped version of '<' character.
+final _LESS_THAN = '&lt;';
+
+/// Chunk the provided name into individual parts to be resolved. We take a
+/// simplistic approach to chunking, though, we break at " ", ",", "&lt;"
+/// and ">". All other characters are grouped into the name to be resolved.
+/// As a result, these characters will all be treated as part of the item to be
+/// resolved (aka the * is interpreted literally as a *, not as an indicator for
+/// bold <em>.
+List<String> _tokenizeComplexReference(String name) {
+  var tokens = [];
+  var append = false;
+  var index = 0;
+  while(index < name.length) {
+    if (name.indexOf(_LESS_THAN, index) == index) {
+      tokens.add(_LESS_THAN);
+      append = false;
+      index += _LESS_THAN.length;
+    } else if (name[index] == ' ' || name[index] == ',' ||
+        name[index] == '>') {
+      tokens.add(name[index]);
+      append = false;
+      index++;
+    } else {
+      if (append) {
+        tokens[tokens.length - 1] = tokens.last + name[index];
+      } else {
+        tokens.add(name[index]);
+        append = true;
+      }
+      index++;
+    }
+  }
+  return tokens;
+}
+
+/// This is a more complex reference. Try to break up if its of the form A<B>
+/// where A is an alphanumeric string and B is an A, a list of B ("B, B, B"),
+/// or of the form A<B>. Note: unlike other the other markdown-style links, all
+/// text inside the square brackets is treated as part of the link (aka the * is
+/// interpreted literally as a *, not as a indicator for bold <em>.
+///
+/// Example: [foo&lt;_bar_>] will produce
+/// <a>resolvedFoo</a>&lt;<a>resolved_bar_</a>> rather than an italicized
+/// version of resolvedBar.
+markdown.Node _fixComplexReference(String name, LibraryMirror currentLibrary,
+    ClassMirror currentClass, MemberMirror currentMember) {
+  // Parse into multiple elements we can try to resolve.
+  var tokens = _tokenizeComplexReference(name);
+
+  // Produce an html representation of our elements. Group unresolved and plain
+  // text are grouped into "link" elements so they display as code.
+  final textElements = [' ', ',', '>', _LESS_THAN];
+  var accumulatedHtml = '';
+
+  for (var token in tokens) {
+    bool added = false;
+    if (!textElements.contains(token)) {
+      String elementName = findElementInScope(token, currentLibrary,
+          currentClass, currentMember);
+      if (elementName != null) {
+        accumulatedHtml += markdown.renderToHtml([new markdown.Element.text(
+            'a', elementName)]);
+        added = true;
+      }
+    }
+    if (!added) {
+      accumulatedHtml += token;
     }
   }
-  return new markdown.Element.text('a', reference);
+  return new markdown.Text(accumulatedHtml);
+}
+
+/// Converts all [foo] references in comments to <a>libraryName.foo</a>.
+markdown.Node fixReference(String name, LibraryMirror currentLibrary,
+    ClassMirror currentClass, MemberMirror currentMember) {
+  // Attempt the look up the whole name up in the scope.
+  String elementName =
+      findElementInScope(name, currentLibrary, currentClass, currentMember);
+  if (elementName != null) {
+    return new markdown.Element.text('a', elementName);
+  }
+  return _fixComplexReference(name, currentLibrary, currentClass, currentMember);
 }
 
 /// Returns a map of [Variable] objects constructed from [mirrorMap].