Yuya Nishihara e4460d5386 op_walk: add error types for fake "opset" expression
This removes CommandError dependency from these resolution functions. We might
want to refactor the error types again if we introduce a real "opset" evaluator.

The error message for unresolved op heads now includes "@" instead of the whole
expression.
2024-01-01 10:22:23 +09:00
..