pkg/dartdoc/lib/mirrors_util.dart

// Copyright (c) 2012, 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('mirrors.util');

// TODO(rnystrom): Use "package:" URL (#4968).
#import('mirrors.dart');
#import('../../../lib/compiler/implementation/util/characters.dart');

//------------------------------------------------------------------------------
// Utility functions for using the Mirror API
//------------------------------------------------------------------------------

/**
 * Returns an iterable over the type declarations directly inheriting from
 * the declaration of this type.
 */
Iterable<InterfaceMirror> computeSubdeclarations(InterfaceMirror type) {
  type = type.declaration;
  var subtypes = <InterfaceMirror>[];
  type.system.libraries.forEach((_, library) {
    for (InterfaceMirror otherType in library.types.values) {
      var superClass = otherType.superclass;
      if (superClass !== null) {
        superClass = superClass.declaration;
        if (type.library === superClass.library) {
          if (superClass == type) {
             subtypes.add(otherType);
          }
        }
      }
      final superInterfaces = otherType.interfaces;
      for (InterfaceMirror superInterface in superInterfaces) {
        superInterface = superInterface.declaration;
        if (type.library === superInterface.library) {
          if (superInterface == type) {
            subtypes.add(otherType);
          }
        }
      }
    }
  });
  return subtypes;
}

LibraryMirror findLibrary(MemberMirror member) {
  ObjectMirror owner = member.surroundingDeclaration;
  if (owner is LibraryMirror) {
    return owner;
  } else if (owner is TypeMirror) {
    return owner.library;
  }
  throw new Exception('Unexpected owner: ${owner}');
}


/**
 * Returns the column of the start of a location.
 */
int getLocationColumn(Location location) {
  String text = location.source.text;
  int index = location.start-1;
  var column = 0;
  while (0 <= index && index < text.length) {
    var charCode = text.charCodeAt(index);
    if (charCode == $CR || charCode == $LF) {
      break;
    }
    index--;
    column++;
  }
  return column;
}

class HierarchyIterable implements Iterable<InterfaceMirror> {
  final bool includeType;
  final InterfaceMirror type;

  HierarchyIterable(this.type, {bool includeType})
      : this.includeType = includeType;

  Iterator<InterfaceMirror> iterator() =>
      new HierarchyIterator(type, includeType: includeType);
}

/**
 * [HierarchyIterator] iterates through the class hierarchy of the provided
 * type.
 *
 * First is the superclass relation is traversed, skipping [Object], next the
 * superinterface relation and finally is [Object] visited. The supertypes are
 * visited in breadth first order and a superinterface is visited more than once
 * if implemented through multiple supertypes.
 */
class HierarchyIterator implements Iterator<InterfaceMirror> {
  final Queue<InterfaceMirror> queue = new Queue<InterfaceMirror>();
  InterfaceMirror object;

  HierarchyIterator(InterfaceMirror type, {bool includeType}) {
    if (includeType) {
      queue.add(type);
    } else {
      push(type);
    }
  }

  InterfaceMirror push(InterfaceMirror type) {
    if (type.superclass !== null) {
      if (type.superclass.isObject) {
        object = type.superclass;
      } else {
        queue.addFirst(type.superclass);
      }
    }
    queue.addAll(type.interfaces);
    return type;
  }

  InterfaceMirror next() {
    InterfaceMirror type;
    if (queue.isEmpty) {
      if (object === null) {
        throw new StateError("No more elements");
      }
      type = object;
      object = null;
      return type;
    } else {
      return push(queue.removeFirst());
    }
  }

  bool get hasNext => !queue.isEmpty || object !== null;
}