644         raise Exception('unable to guess selection variables')

   644         raise Exception('unable to guess selection variables')

   645     return mainvars

   645     return mainvars

   646 

   646 

   647 def split_expression(rqlstring):

   647 def split_expression(rqlstring):

   648     for expr in rqlstring.split(','):

   648     for expr in rqlstring.split(','):

   652 

   653 

   653 def normalize_expression(rqlstring):

   654 def normalize_expression(rqlstring):

   654     """normalize an rql expression to ease schema synchronization (avoid

   655     """normalize an rql expression to ease schema synchronization (avoid

   655     suppressing and reinserting an expression if only a space has been

   656     suppressing and reinserting an expression if only a space has been

   656     added/removed for instance)

   657     added/removed for instance)