TypeError for foreign unhashable types about pymbolic HOT 4 CLOSED

Hello @redrossa.
Could you please attach a minimal failing script that would make this behavior clearer, because at least for primitve expression nodes provided by pymbolic equality comparison doesn't go through a Mapper.

from pymbolic.

Hello @kaushikcfd

My main issue is that I'm trying to compare a pymbolic expression tree to another. However the following example snippet will fail:

Sum(([1,2], [1,2])) == Sum(([1,2], [1,2]))

I'm not sure if this was intentional to force users to create an expression wrapper for foreign, non-primitive and especially unhashable types, like lists, but if it was, it seems quite inconsistent with the design of the Mapper class where it can directly visit expressions whose nodes are lists or even numpy arrays since it provides signatures for map_list or even map_numpy_array unimplemented methods.

from pymbolic.

It might be worth it to change __eq__ to also use the mapper infrastructure. The second argument could be used for the traversal of the second argument. This would give us a bit more dispatch flexibility. I'd be happy to consider a PR.

from pymbolic.

@inducer Are you talking about changing __eq__ to an implementation similar to __str__ using a mapper? I think that would definitely allow users to customize how foreign object nodes would equalize against another.

from pymbolic.