Guile now have both guardian and finalizer. Guardian API can be directly
accessed from Scheme, but finalizer API only available in (system foreign-object).

I see they're all based on the finalize mechanism of libgc, what's the
difference between them?

If I want to manage the destruction of a foreign pointer, which one is recommended?
-- 
Retrieve my PGP public key:

  gpg --recv-keys D47A9C8B2AE3905B563D9135BE42B352A9F6821F

Zihao