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 <[email protected]> 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 <[email protected]> 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 <[email protected]> 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 <[email protected]> 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 <[email protected]> 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 <[email protected]> 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 [email protected]. > >>> > > 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 [email protected]. > >>> > >>> 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 [email protected]. > > 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. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6KPs8k9PTJTEVvmJT4dBsnNho%3DRgU0HN6p1W9hPb5D4tg%40mail.gmail.com.
