MatchResult dictionary for pattern rewrite #1387
Description
Consider a pattern such as Add(MatMul(X,Y), Z). Every successful match of this pattern in an input model will bind variables X, Y and Z to values in the IR representation of the model.
The existing two representations of MatchResult return a dictionary mapping the variable names (like "X") to a value. But one representation returns the IR-value that X is bound to, while the second representation returns the IR-value's name instead. It would be good to reconcile this difference.
My suggestion is to use the first one. This makes it easier for the user-code, because they use this to check things like the shape or type of the value X is bound to, or whether it is a constant-value, etc. Given the name, the users have to do an additional lookup on the model/graph to go from the name to the IR-value. And when we write a rule, we don't even have the model/graph available.
See examples in the repo or this document