 
            
            
            
            
                12 Mar
                
                    2012
                
            
            
                12 Mar
                
                '12
                
            
            
            
        
    
                1:55 p.m.
            
        I mostly figured this out. stToIO allows converting (ST s a) to (IO a) and so I can update the bloom filter in IO. I do still wonder if there's a better way, avoiding modifying the filter inside IO and keeping it in ST. -- see shy jo