Hernan M Foffani wrote: >> It would be great to have LINQ in IronPython - but I don't think it can >> be done without extending the Python syntax. Understandably the Python >> community will be concerned about this. >> >> Fortunately Python has a built-in way of enabling (or disabling) >> language features - the __future__ imports. >> >> If you could agree with the Python developers to get a 'reserved' flag >> for LINQ (one that CPython promises never to use) then develoeprs could >> enable LINQ by starting files with: >> >> from __future__ import LINQ >> > > Some time ago I was wondering if it would be possible to have an > object that takes a generator expression and translates its AST > into LINQ expressions (actually, not LINQ extended syntax but > the .NET 3.0 API ) > > With this approach, of course, you won't be able to get LINQ's > full power inside Python, but I think that staying within Python > syntax is nice. >
I've been thinking about a similar approach - where list comprehensions (or generator expressions) could actually translate to API calls on the iterable (the data provider). Perhaps with a magic method like '__query__'. Python (or IronPython) would have to then check for this magic method in every list comprehension - perhaps hitting performance. It would also have to *keep* the AST for the filter expression. I think this still amounts to an extension of Python though by adding new protocols - but it is a nice generalisation. Generating queries from ASTs sounds non-trivial, but Microsoft have done it for LINQ. I have a blog entry about this waiting in the wings. Just providing a LINQ function that takes a generator expression is an interesting approach. IronPython would still have to do some magic to generate an expression tree from the filter expression. Michael http://www.manning.com/foord > To be honest I haven't gave it much thought to this so I don't know > if it's possible, or even worth it, at all. > > Regards, > -Hernán. > _______________________________________________ > Users mailing list > [email protected] > http://lists.ironpython.com/listinfo.cgi/users-ironpython.com > > _______________________________________________ Users mailing list [email protected] http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
