I proposed a solution in this PR https://github.com/sympy/sympy/pull/22887 which stores the (lambda) function in a wrapper class subclassing from Atom, thus circumventing storing any non-Basic in args. On Friday, 1 October 2021 at 00:28:14 UTC+2 asme...@gmail.com wrote:
> It is relevant to think about how we might do this in other ways, > though, because if we ever want to make Functions themselves Basic > objects we would need to refactor them in a similar way > (https://github.com/sympy/sympy/issues/4787). In fact, if Functions > were objects, we could just store the function object on the > QuantumGate args. > > Aaron Meurer > > On Thu, Sep 30, 2021 at 4:24 PM Aaron Meurer <asme...@gmail.com> wrote: > > > > My understanding is that an OracleGate is just the quantum version of > > Function. It probably should just be Function (maybe a subclass that > > mixes Function and Gate), with users creating oracles by subclassing > > and defining eval. > > > > Aaron Meurer > > > > On Thu, Sep 30, 2021 at 4:12 PM Chris Smith <smi...@gmail.com> wrote: > > > > > > https://qiskit.org/textbook/ch-gates/oracles.html > > > > > > On Thursday, September 30, 2021 at 3:13:15 PM UTC-5 Oscar wrote: > > >> > > >> I don't know what the OracleGate class is for but I'm pretty sure > it's not very useful and it's certainly poorly designed. I'd rather just > delete it than try to come up with hacks to make it work. > > >> > > >> If someone wants to maintain the quantum module then that's great. > Until then we shouldn't allow broken code like this to complicate the > maintained part of the codebase. > > >> > > >> Oscar > > >> > > >> On Thu, 30 Sept 2021 at 21:08, Aaron Meurer <asme...@gmail.com> > wrote: > > >>> > > >>> Although storing f in the .args of an expression would be just as > > >>> problematic as storing a lambda, because functions are not objects. > So > > >>> you might need to make a custom evaluator class similar to Lambda > that > > >>> stores a given lambda on it. It's a little messy because it breaks > > >>> with the SymPy pattern that objects should only store symbolic data. > > >>> > > >>> Aaron Meurer > > >>> > > >>> On Thu, Sep 30, 2021 at 2:02 PM Aaron Meurer <asme...@gmail.com> > wrote: > > >>> > > > >>> > So it sounds like OracleGate needs the function to not be symbolic > at > > >>> > all. You can use the following to create a symbolic function that > > >>> > evaluates as a given lambda: > > >>> > > > >>> > >>> f = Function('f', eval=lambda x: x == 1) > > >>> > >>> f(1) > > >>> > True > > >>> > >>> f(0) > > >>> > False > > >>> > > > >>> > Aaron Meurer > > >>> > > > >>> > On Wed, Sep 29, 2021 at 8:19 PM Chris Smith <smi...@gmail.com> > wrote: > > >>> > > > > >>> > > The problem is that this returns an Eq instead of False when it > is not equal: > > >>> > > ``` > > >>> > > >>> f = lambda x: x == 1 > > >>> > > >>> F = Lambda(x, f(SymbolicEquality(x))) > > >>> > > >>> F(1) > > >>> > > True > > >>> > > >>> F(x) > > >>> > > Eq(x, 1) > > >>> > > >>> f(x) > > >>> > > False > > >>> > > ``` > > >>> > > > > >>> > > On Tuesday, September 28, 2021 at 1:42:27 AM UTC-5 Oscar wrote: > > >>> > >> > > >>> > >> On Tue, 28 Sept 2021 at 04:13, Chris Smith <smi...@gmail.com> > wrote: > > >>> > >>> > > >>> > >>> I would like to emulate something like this with Basic > objects. I am drawing a blank on how that might be done. Does anyone have > any ideas? > > >>> > >>> > > >>> > >>> >>> f=lambda x: x==1 > > >>> > >>> >>> f(1) > > >>> > >>> True > > >>> > >>> >>> Lambda(x, f(x))(1) # doesn't work > > >>> > >>> False > > >>> > >> > > >>> > >> > > >>> > >> Something like this: > > >>> > >> > > >>> > >> In [7]: cat w.py > > >>> > >> class SymbolicEquality: > > >>> > >> def __init__(self, sym): > > >>> > >> self.sym = sym > > >>> > >> def __eq__(self, other): > > >>> > >> return Equality(self.sym, other) > > >>> > >> > > >>> > >> In [8]: f = lambda x: x == 1 > > >>> > >> > > >>> > >> In [9]: y = Dummy('y') > > >>> > >> > > >>> > >> In [10]: F = Lambda(y, f(SymbolicEquality(y))) > > >>> > >> > > >>> > >> In [11]: F > > >>> > >> Out[11]: y ↦ y = 1 > > >>> > >> > > >>> > >> -- > > >>> > >> Oscar > > >>> > > > > >>> > > -- > > >>> > > You received this message because you are subscribed to the > Google Groups "sympy" group. > > >>> > > To unsubscribe from this group and stop receiving emails from > it, send an email to sympy+un...@googlegroups.com. > > >>> > > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/13d15197-0d82-4312-b94a-ec59df616aedn%40googlegroups.com > . > > >>> > > >>> -- > > >>> You received this message because you are subscribed to the Google > Groups "sympy" group. > > >>> To unsubscribe from this group and stop receiving emails from it, > send an email to sympy+un...@googlegroups.com. > > >>> > > >>> To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/CAKgW%3D6%2Bt1wkS_mEg3AruG%2BLahUfDqqszP0ZAbi5XCsW4KXA4yw%40mail.gmail.com > . > > > > > > -- > > > You received this message because you are subscribed to the Google > Groups "sympy" group. > > > To unsubscribe from this group and stop receiving emails from it, send > an email to sympy+un...@googlegroups.com. > > > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/eae0a8a1-2742-4d06-9581-3f0804ebe06cn%40googlegroups.com > . > -- You received this message because you are subscribed to the Google Groups "sympy" group. 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