def macroexpand(tree, compiler):
 load_macros(compiler.module_name)
 old = None
 while (old != tree):
  old = tree
  tree = macroexpand_1(tree, compiler)
 return tree

def macroexpand ( tree , compiler ) : load_macros ( compiler . module_name ) old = None while ( old != tree ) : old = tree tree = macroexpand_1 ( tree , compiler ) return tree
expand the toplevel macros for the tree .