pkg/docgen: refactoring and cleanup

pkg/docgen/lib/src/utils.dart

+library docgen.utils;
+
+import '../../../../sdk/lib/_internal/compiler/implementation/mirrors/source_mirrors.dart';
+import '../../../../sdk/lib/_internal/compiler/implementation/mirrors/mirrors_util.dart'
+    as dart2js_util;
+import '../../../../sdk/lib/_internal/libraries.dart';
+
+// HTML escaped version of '<' character.
+const LESS_THAN = '&lt;';
+
+/// A declaration is private if itself is private, or the owner is private.
+// Issue(12202) - A declaration is public even if it's owner is private.
+bool isHidden(DeclarationMirror mirror) {
+  if (mirror is LibraryMirror) {
+    return _isLibraryPrivate(mirror);
+  } else if (mirror.owner is LibraryMirror) {
+    return (mirror.isPrivate || _isLibraryPrivate(mirror.owner) ||
+        mirror.isNameSynthetic);
+  } else {
+    return (mirror.isPrivate || isHidden(mirror.owner) ||
+        mirror.isNameSynthetic);
+  }
+}
+
+/// Returns true if a library name starts with an underscore, and false
+/// otherwise.
+///
+/// An example that starts with _ is _js_helper.
+/// An example that contains ._ is dart._collection.dev
+bool _isLibraryPrivate(LibraryMirror mirror) {
+  // This method is needed because LibraryMirror.isPrivate returns `false` all
+  // the time.
+  var sdkLibrary = LIBRARIES[dart2js_util.nameOf(mirror)];
+  if (sdkLibrary != null) {
+    return !sdkLibrary.documented;
+  } else if (dart2js_util.nameOf(mirror).startsWith('_') || dart2js_util.nameOf(
+      mirror).contains('._')) {
+    return true;
+  }
+  return false;
+}
+
+/// Transforms the map by calling toMap on each value in it.
+Map recurseMap(Map inputMap) {
+  var outputMap = {};
+  inputMap.forEach((key, value) {
+    if (value is Map) {
+      outputMap[key] = recurseMap(value);
+    } else {
+      outputMap[key] = value.toMap();
+    }
+  });
+  return outputMap;
+}
+
+Map filterMap(Map map, Function test) {
+  var exported = new Map();
+  map.forEach((key, value) {
+    if (test(key, value)) exported[key] = value;
+  });
+  return exported;
+}
+
+/// 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;
+}
+
+typedef DeclarationMirror LookupFunction(DeclarationSourceMirror declaration,
+    String name);
+
+/// For a given name, determine if we need to resolve it as a qualified name
+/// or a simple name in the source mirors.
+LookupFunction determineLookupFunc(String name) => name.contains('.') ?
+    dart2js_util.lookupQualifiedInScope :
+      (mirror, name) => mirror.lookupInScope(name);