Excuse me, I did not write sooner. It was nessesary to do all thing related to university. Now Im afraid I have no time. But anyway,
> OK. What exactly would like to implement? I red this issue https://github.com/sympy/sympy/wiki/Parsing Well, the task is to implement a parser framework for sympy that will support unambigious grammars. Unfortunately, I have never been in touch with Earley algorithm. So I thought, final approach is to implement flexible parse classes that can potentially describe grammars of text formats which uses Mathematica6/7/8, Maxima, and LaTeX style input, etc. Common pattern for this tasks that I know is Haskell-like monadic parse combinators, but they can give low perfomance in python. Also, I choose this issue http://code.google.com/p/sympy/issues/detail?id=1374&colspec=ID%20Type%20Status%20Priority%20Milestone%20Reporter%20Summary%20Stars&start=100 but have faced with a problem. There are several ways to fix it: 1) assume that Float(2.0) should return Integer(2), but its a `horrible' way, because Float constructor expected to return Float values. And tests show that many modules rely on behavior of Float. I decided not to modify standard sympy type system. 2) fix Add.flatten function. It uses `terms' dictionary for reduction, and hash(x**2) is not equal to hash(x**2.0) but x**2 == x**2.0 is True. Thus, have tried to look similar values in terms.keys() directly and its work pretty good, except that test_minimal_polynomial() in sympy.polys.tests fails at string 92: assert minimal_polynomial(sqrt(a) + sqrt(sqrt(a)), x) == f it goes into infinite recursion. Have no idea how to consider this case. I will be glad to work outside of gsoc programm. -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
