So the problem `types` got re-defined since I called `import cirruParser/types` before current importing. I got a solution finally by modifying the source of the parser to export functions at namespace `cirruParser` then I don't need to import `cirruPraser/types` anymore. Works for now.
Turned out it can be bad habit to import `pkg/file` modules from other packages. All functions should be exported at `pkg`'s namespace.
