ast_utils: Added support for WithMeta (Initial)

lark/ast_utils.py

@@ -19,13 +19,22 @@ class AsList(object):
     Subclasses will be instanciated with the parse results as a single list, instead of as arguments.
     """
 
+class WithMeta(object):
+    pass
+
 def camel_to_snake(name):
     return re.sub(r'(?<!^)(?=[A-Z])', '_', name).lower()
 
 def _call(func, _data, children, _meta):
     return func(*children)
+def _call_with_meta(func, _data, children, meta):
+    return func(meta, children)
+def _call_with_meta_inline(func, _data, children, meta):
+    return func(meta, *children)
 
 inline = v_args(wrapper=_call)
+with_meta = v_args(wrapper=_call_with_meta)
+with_meta_inline = v_args(wrapper=_call_with_meta_inline)
 
 def create_transformer(ast_module, transformer=None):
     """Collects `Ast` subclasses from the given module, and creates a Lark transformer that builds the AST.
@@ -45,7 +54,11 @@ def create_transformer(ast_module, transformer=None):
         if not name.startswith('_') and inspect.isclass(obj):
             if issubclass(obj, Ast):
                 if not issubclass(obj, AsList):
-                    obj = inline(obj).__get__(t)
+                        obj = with_meta_inline(obj).__get__(t)
+                    else:
+                        obj = inline(obj).__get__(t)
+                elif issubclass(obj, WithMeta):
+                    obj = with_meta(obj).__get__(t)
 
                 setattr(t, camel_to_snake(name), obj)