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 <asmeu...@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
> >
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