def _tree_hash(node: SExp, precalculated: Set[bytes32]) -> bytes32:
"""
Hash values in `precalculated` are presumed to have been hashed already.
"""
if node.listp():
left = _tree_hash(node.first(), precalculated)
right = _tree_hash(node.rest(), precalculated)
s = b"\2" + left + right
else:
atom = node.as_atom()
if atom in precalculated:
return bytes32(atom)
s = b"\1" + atom
return bytes32(std_hash(s))
def ir_as_symbol(ir_sexp: SExp) -> typing.Optional[str]:
if ir_sexp.listp() and ir_type(ir_sexp) == Type.SYMBOL:
return bytes(ir_as_sexp(ir_sexp).as_atom()).decode("utf8")
return None
