On 12/19/10 12:40, Brent Spillner wrote:
I uploaded sample code to the Vault (in the "Miscellaneous/" directory) that provides a concise notation for list comprehensions. The comprehensions are evaluated lazily and can be used to populate a std::list, vector, or deque, appended to the same, inserted after a given iterator, or interpreted as a boost::range, including compatibility with BOOST_FOREACH. Containers, iterator-defined ranges, or nullary function objects can be used as generators, and arbitrary function objects can be used to specify filter conditions.
List comprehensions in haskell can be done with monads: http://book.realworldhaskell.org/read/monads.html Why not 1st define a c++ monad and then define the list comprehension using the moand? If that were done, then boost would have both. Actually, fcpp already has it in monad.h. Fcpp is available at sourceforge: http://sourceforge.net/projects/fcpp/ However, I've not used fcpp and several years ago boost reviewed it but decided not to include it. http://lists.boost.org/Archives/boost/2004/02/61840.php However, I think defining a monad acceptable to boost would be useful since it is used extensively in functional programming. -regards, Larry