mojom: Add associative arrays to the mojom language.

mojo/public/tools/bindings/pylib/mojom/parse/translate.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.
 
 """Translates parse tree to Mojom IR."""
 
 
 import re
 
 from . import ast
 
 
 def _MapTreeForType(func, tree, type_to_map):
   assert isinstance(type_to_map, type)
   if not tree:
     return []
   return [func(subtree) for subtree in tree if isinstance(subtree, type_to_map)]
 
 _FIXED_ARRAY_REGEXP = re.compile(r'\[[0-9]+\]')
 
-def _MapKind(kind):
+def MapKind(kind):
   map_to_kind = {'bool': 'b',
                  'int8': 'i8',
                  'int16': 'i16',
                  'int32': 'i32',
                  'int64': 'i64',
                  'uint8': 'u8',
                  'uint16': 'u16',
                  'uint32': 'u32',
                  'uint64': 'u64',
                  'float': 'f',
                  'double': 'd',
                  'string': 's',
                  'handle': 'h',
                  'handle<data_pipe_consumer>': 'h:d:c',
                  'handle<data_pipe_producer>': 'h:d:p',
                  'handle<message_pipe>': 'h:m',
                  'handle<shared_buffer>': 'h:s'}
   if kind.endswith('?'):
-    base_kind = _MapKind(kind[0:-1])
+    base_kind = MapKind(kind[0:-1])
     # NOTE: This doesn't rule out enum types. Those will be detected later, when
     # cross-reference is established.
-    reference_kinds = ('s', 'h', 'a', 'r', 'x')
+    reference_kinds = ('m', 's', 'h', 'a', 'r', 'x')
     if base_kind[0] not in reference_kinds:
       raise Exception(
           'A type (spec "%s") cannot be made nullable' % base_kind)
     return '?' + base_kind
+  first_curly = kind.find('{')
+  if first_curly != -1:
+    # We want to parse associative arrays from left to right as much as
+    # possible. So remove remove the first associative array key as the key
+    # type, and pass the rest (which may be an array) to ourselves recursively.
+    closing_curly = kind.find('}', first_curly)
+    key = kind[first_curly+1:closing_curly]
+    rest = kind[0:first_curly] + kind[closing_curly+1:]
+    return 'm[' + MapKind(key) + '][' + MapKind(rest) + ']'
   if kind.endswith('[]'):
     typename = kind[0:-2]
     if _FIXED_ARRAY_REGEXP.search(typename):
       raise Exception('Arrays of fixed sized arrays not supported')
-    return 'a:' + _MapKind(typename)
+    return 'a:' + MapKind(typename)
   if kind.endswith(']'):
     lbracket = kind.rfind('[')
     typename = kind[0:lbracket]
     if typename.find('[') != -1:
       raise Exception('Fixed sized arrays of arrays not supported')
-    return 'a' + kind[lbracket+1:-1] + ':' + _MapKind(typename)
+    return 'a' + kind[lbracket+1:-1] + ':' + MapKind(typename)
   if kind.endswith('&'):
-    return 'r:' + _MapKind(kind[0:-1])
+    return 'r:' + MapKind(kind[0:-1])
   if kind in map_to_kind:
     return map_to_kind[kind]
   return 'x:' + kind
 
 def _AttributeListToDict(attribute_list):
   if attribute_list is None:
     return {}
   assert isinstance(attribute_list, ast.AttributeList)
   # TODO(vtl): Check for duplicate keys here.
   return dict([(attribute.key, attribute.value)
                    for attribute in attribute_list])
 
 def _EnumToDict(enum):
   def EnumValueToDict(enum_value):
     assert isinstance(enum_value, ast.EnumValue)
     return {'name': enum_value.name,
             'value': enum_value.value}
 
   assert isinstance(enum, ast.Enum)
   return {'name': enum.name,
           'fields': map(EnumValueToDict, enum.enum_value_list)}
 
 def _ConstToDict(const):
   assert isinstance(const, ast.Const)
   return {'name': const.name,
-          'kind': _MapKind(const.typename),
+          'kind': MapKind(const.typename),
           'value': const.value}
 
 
 class _MojomBuilder(object):
   def __init__(self):
     self.mojom = {}
 
   def Build(self, tree, name):
     def StructToDict(struct):
       def StructFieldToDict(struct_field):
         assert isinstance(struct_field, ast.StructField)
         return {'name': struct_field.name,
-                'kind': _MapKind(struct_field.typename),
+                'kind': MapKind(struct_field.typename),
                 'ordinal': struct_field.ordinal.value \
                     if struct_field.ordinal else None,
                 'default': struct_field.default_value}
 
       assert isinstance(struct, ast.Struct)
       return {'name': struct.name,
               'attributes': _AttributeListToDict(struct.attribute_list),
               'fields': _MapTreeForType(StructFieldToDict, struct.body,
                                         ast.StructField),
               'enums': _MapTreeForType(_EnumToDict, struct.body, ast.Enum),
               'constants': _MapTreeForType(_ConstToDict, struct.body,
                                            ast.Const)}
 
     def InterfaceToDict(interface):
       def MethodToDict(method):
         def ParameterToDict(param):
           assert isinstance(param, ast.Parameter)
           return {'name': param.name,
-                  'kind': _MapKind(param.typename),
+                  'kind': MapKind(param.typename),
                   'ordinal': param.ordinal.value if param.ordinal else None}
 
         assert isinstance(method, ast.Method)
         rv = {'name': method.name,
               'parameters': map(ParameterToDict, method.parameter_list),
               'ordinal': method.ordinal.value if method.ordinal else None}
         if method.response_parameter_list is not None:
           rv['response_parameters'] = map(ParameterToDict,
                                           method.response_parameter_list)
         return rv
@@ skipping 22 matching lines @@
         _MapTreeForType(InterfaceToDict, tree.definition_list, ast.Interface)
     self.mojom['enums'] = \
         _MapTreeForType(_EnumToDict, tree.definition_list, ast.Enum)
     self.mojom['constants'] = \
         _MapTreeForType(_ConstToDict, tree.definition_list, ast.Const)
     return self.mojom
 
 
 def Translate(tree, name):
   return _MojomBuilder().Build(tree, name)