[lhorie]

For parsing specifically, I haven't felt the need for them (errdefer is not really relevant since I don't typically need to clean up resources half-way through parsing, and likewise, zig stack traces aren't necessarily as useful to an end user as contextual parsing metadata.

I do use errors for other stuff, and I wish I could, for example, attach actionable error messages to errors, to be dispatched to whatever logging mechanism is setup. Bubbling up an error from stdlib and printing it from main makes for poor end user experience, and pattern matching an entire application's worth of an error union in order to map an error to a descriptive message is not as ideal as writing the messages where they come from as you would w/ e.g. golang's `errors.New(message)`.