miniscript_to_sympy thresh error

[brenorb]

When using the complex miniscript policy below, it yields the following type error.

TypeError: expecting bool or Boolean, not (2, [pk.dave, pk.eve, pk.frank]).

Snippet which raises the error:

if function_name in ['and', 'or']:
            if len(function_args) != 2:
                raise ValueError(f"Invalid number of arguments for {function_name}: {len(function_args)}")
            left = miniscript_to_sympy(function_args[0])
            right = miniscript_to_sympy(function_args[1])
            return And(left, right) if function_name == 'and' else Or(left, right)

Input: miniscript = 'and(or(pk(alice),and(pk(bob),older(10080))),or(and(pk(charlie),sha256(h)),thresh(2,pk(dave),pk(eve),pk(frank))))'

It looks like the problem is the way it handles thresh, which is creating a tuple, that works fine when thresh is the root function, but seems to break when it is a child function.

Idea: A possible solution maybe could be transforming the whole tuple in a string, or making it a symbol like functions which are not boolean, however it might break later functions.

[brenorb]

A new idea involves parsing and simplifying from deeper threshs. Then, transform the entire thresh subfunctions into variables for later simplification in an upper level.