Mojo: Mojom: Add AST types for struct and struct body.

mojo/public/tools/bindings/pylib/mojom/parse/ast.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Node classes for the AST for a Mojo IDL file."""
 
 # Note: For convenience of testing, you probably want to define __eq__() methods
 # for all node types; it's okay to be slightly lax (e.g., not compare filename
 # and lineno). You may also define __repr__() to help with analyzing test
 # failures, especially for more complex types.
 
 
 class NodeBase(object):
   """Base class for nodes in the AST."""
 
   def __init__(self, filename=None, lineno=None):
     self.filename = filename
     self.lineno = lineno
 
   def __eq__(self, other):
     return type(self) == type(other)
 
 
 # TODO(vtl): Some of this is complicated enough that it should be tested.
 class NodeListBase(NodeBase):
   """Represents a list of other nodes, all having the same type. (This is meant
-  to be subclassed, with subclasses defining _list_item_type to be the class of
-  the members of the list; _list_item_type should also be a NodeBase.)"""
+  to be subclassed, with subclasses defining _list_item_type to be the class (or
+  classes, in a tuple) of the members of the list.)"""
 
   def __init__(self, item_or_items=None, **kwargs):
-    assert issubclass(self._list_item_type, NodeBase)
     super(NodeListBase, self).__init__(**kwargs)
+    self.items = []
     if item_or_items is None:
-      self.elements = []
+      pass
+      self.items = []
     elif isinstance(item_or_items, list):
-      # TODO(vtl): Possibly we should assert that each element of the list is a
-      # |_list_item_type|.
-      self.elements = list(item_or_items)
+      for item in item_or_items:
+        assert isinstance(item, self._list_item_type)
+        self.Append(item)
     else:
       assert isinstance(item_or_items, self._list_item_type)
-      self.elements = [item_or_items]
-    self._UpdateFilenameAndLineno()
+      self.Append(item_or_items)
 
-  # Support iteration. For everything else, users should just access |elements|
+  # Support iteration. For everything else, users should just access |items|
   # directly. (We intentionally do NOT supply |__len__()| or |__nonzero__()|, so
   # |bool(NodeListBase())| is true.)
   def __iter__(self):
-    return self.elements.__iter__()
+    return self.items.__iter__()
 
   def __eq__(self, other):
     return super(NodeListBase, self).__eq__(other) and \
-           len(self.elements) == len(other.elements) and \
-           all(self.elements[i] == other.elements[i] \
-                   for i in xrange(len(self.elements)))
+           len(self.items) == len(other.items) and \
+           all(self.items[i] == other.items[i] for i in xrange(len(self.items)))
 
   # Implement this so that on failure, we get slightly more sensible output.
   def __repr__(self):
     return self.__class__.__name__ + "([" + \
-           ", ".join([repr(elem) for elem in self.elements]) + "])"
+           ", ".join([repr(elem) for elem in self.items]) + "])"
+
+  def Insert(self, item):
+    """Inserts item at the front of the list."""
+
+    assert isinstance(item, self._list_item_type)
+    self.items.insert(0, item)
+    self._UpdateFilenameAndLineno()
 
   def Append(self, item):
+    """Appends item to the end of the list."""
+
     assert isinstance(item, self._list_item_type)
-    self.elements.append(item)
+    self.items.append(item)
     self._UpdateFilenameAndLineno()
 
   def _UpdateFilenameAndLineno(self):
-    if self.elements:
-      self.filename = self.elements[0].filename
-      self.lineno = self.elements[0].lineno
+    if self.items:
+      self.filename = self.items[0].filename
+      self.lineno = self.items[0].lineno
 
 
 class Definition(NodeBase):
   """Represents a definition of anything that has a global name (e.g., enums,
   enum values, consts, structs, struct fields, interfaces). (This does not
   include parameter definitions.) This class is meant to be subclassed."""
 
   def __init__(self, name, **kwargs):
     assert isinstance(name, str)
     NodeBase.__init__(self, **kwargs)
@@ skipping 168 matching lines @@
            self.ordinal == other.ordinal and \
            self.typename == other.typename
 
 
 class ParameterList(NodeListBase):
   """Represents a list of (method request or response) parameters."""
 
   _list_item_type = Parameter
 
 
+class Struct(Definition):
+  """Represents a struct definition."""
+
+  def __init__(self, name, attribute_list, body, **kwargs):
+    assert attribute_list is None or isinstance(attribute_list, AttributeList)
+    assert isinstance(body, StructBody)
+    super(Struct, self).__init__(name, **kwargs)
+    self.attribute_list = attribute_list
+    self.body = body
+
+  def __eq__(self, other):
+    return super(Struct, self).__eq__(other) and \
+           self.attribute_list == other.attribute_list and \
+           self.body == other.body
+
+
 class StructField(Definition):
   """Represents a struct field definition."""
 
   def __init__(self, name, ordinal, typename, default_value, **kwargs):
     assert isinstance(name, str)
     assert ordinal is None or isinstance(ordinal, Ordinal)
     assert isinstance(typename, str)
     # The optional default value is currently either a value as a string or a
     # "wrapped identifier".
     assert default_value is None or isinstance(default_value, (str, tuple))
     super(StructField, self).__init__(name, **kwargs)
     self.ordinal = ordinal
     self.typename = typename
     self.default_value = default_value
 
   def __eq__(self, other):
     return super(StructField, self).__eq__(other) and \
            self.ordinal == other.ordinal and \
            self.typename == other.typename and \
            self.default_value == other.default_value
+
+
+# This needs to be declared after |StructField|.
+class StructBody(NodeListBase):
+  """Represents the body of (i.e., list of definitions inside) a struct."""
+
+  _list_item_type = (Const, Enum, StructField)