From: mailbox@dmitry-kazakov.de   
      
   On 2022-11-24 23:51, Tim Rentsch wrote:   
      
   > For the general case we would like to handle any circular measure   
   > (for convenience having coordinates in some integer range).   
      
   Not necessarily circular. The same issue arise with overflowing   
   counters. E.g. the typical case when you have some real-time clock   
   counter which periodically runs over and you have to detect overflows.   
      
   > Exercise: write a function to answer this kind of question for   
   > circular measures in general.  You may assume integer coordinates   
   > and intervals that include the starting point but do not include   
   > the end point.  Give a suitable declaration for the function,   
   > and separately give a function definition to implement the given   
   > interface.   
      
   Usual technique is expanding the range this or that way. E.g.   
      
   - Computing differences in the specified direction and complementing by   
   the modulo when the difference turns negative.   
   - Using large non-modular numbers that never overflow, e.g. with indices   
   of a ring buffer. A 64-bit sequence number I is the new "index." To   
   access elements I mod N is used.   
      
   --   
   Regards,   
   Dmitry A. Kazakov   
   http://www.dmitry-kazakov.de   
      
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