Mojo: Mojom: Add AST types for imports and import lists.

R=davemoore@chromium.org

Review URL: https://codereview.chromium.org/382553004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@282184 0039d316-1c4b-4281-b951-d872f2087c98

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

@@ -88,6 +88,24 @@ class AttributeList(NodeListBase):
   _list_item_type = Attribute
 
 
+class Import(NodeBase):
+  """Represents an import statement."""
+
+  def __init__(self, import_filename, **kwargs):
+    assert isinstance(import_filename, str)
+    NodeBase.__init__(self, **kwargs)
+    self.import_filename = import_filename
+
+  def __eq__(self, other):
+    return self.import_filename == other.import_filename
+
+
+class ImportList(NodeListBase):
+  """Represents a list (i.e., sequence) of import statements."""
+
+  _list_item_type = Import
+
+
 class Module(NodeBase):
   """Represents a module statement."""
 

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

@@ -87,26 +87,34 @@ class Parser(object):
   # See http://www.dabeaz.com/ply/ply.html#ply_nn25 for more details.
 
   # TODO(vtl): Get rid of this ('MODULE', ...) stuff and replace it with an
-  # ast.Mojom node. This will require putting the imports into a list (say
-  # ast.ImportList).
+  # ast.Mojom node. (The ('IMPORT', ...) stuff is a hack until I do this and
+  # update translate.py.)
   # TODO(vtl): Get rid of the braces in the module "statement". (Consider
   # renaming "module" -> "package".)
   def p_root(self, p):
-    """root : import root
-            | module LBRACE definition_list RBRACE
-            | definition_list"""
-    if len(p) == 3:
-      p[0] = p[2]
-      p[0].insert(0, p[1])
-    elif len(p) == 5:
-      p[0] = [('MODULE', p[1].name, p[1].attribute_list, p[3])]
+    """root : import_list module LBRACE definition_list RBRACE
+            | import_list definition_list"""
+    p[0] = [('IMPORT', import_statement.import_filename) \
+                for import_statement in p[1]]
+    if len(p) == 6:
+      p[0].append(('MODULE', p[2].name, p[2].attribute_list, p[4]))
     else:
-      p[0] = [('MODULE', None, None, p[1])]
+      p[0].append(('MODULE', None, None, p[2]))
+
+  def p_import_list_1(self, p):
+    """import_list : """
+    p[0] = ast.ImportList()
+
+  def p_import_list_2(self, p):
+    """import_list : import_list import"""
+    p[0] = p[1]
+    p[0].Append(p[2])
 
   def p_import(self, p):
     """import : IMPORT STRING_LITERAL"""
     # 'eval' the literal to strip the quotes.
-    p[0] = ('IMPORT', eval(p[2]))
+    # TODO(vtl): This eval is dubious. We should unquote/unescape ourselves.
+    p[0] = ast.Import(eval(p[2]))
 
   def p_module(self, p):
     """module : attribute_section MODULE identifier_wrapped """