Hi Maxim, Maxim Cournoyer 写道: > For some background reading, see [0]. Thanks for the well-thought-out reply, and sharing this interesting link! Now, it's just the musings of one person, but now I think I do agree with (what I think is) the underlying vision: to hush up *unspecified* and sneakily replace it with true nothingness. OK, I can live with that. :-) > I think the semantic of the language is that it is to be used as > the > lack of a return value from a procedure or syntax, e.g.: > > (unspecified? (if #f 'one-arm-if)) -> #t Well… in the above context I'd hesitate to even imply ‘semantics’. It's like undefined behaviour in C. Ascribe it meaning at your peril. Otherwise, point taken. > Having 'unspecified?' even defined in Guile seems to go against > that > idea; perhaps because Wingo themselves seems to disagree in [0]. Agreed. *This* was one of my reasons for supporting (field *unspecified*), so it's nice to have it validated, even if it is rejected. > I'm also thinking 'unspecified being too close to *unspecified* > is > probably going to cause confusion down the line. Reverting to > the > originally used 'disabled may be the lesser evil. Ah, here I can concentrate all my previous disagreement: hell no :-) It is the worstest evil; literally anything is better than (enable-foo? 'disabled) defaulting to #t. Bikeshed this all y'all want, but 'default or 'unset or 'whatever are miles better. Kind regards, T G-R