Arun Isaac <[email protected]> writes: > Alex Vong <[email protected]> writes: > >> I think the problem is that when the scheme standard says "the returned >> value is unspecified", it means anything can be returned. In this case, >> guile choose to return an unspecified value to avoid returning an >> arbitary value. >> >> I think the answer written by soegaard in [0] explains it pretty well. >> >> [0]: >> https://stackoverflow.com/questions/28910911/detecting-unspecified-in-scheme-list > > This is new to me. But, since we only use the Guile implementation, I > think we should be ok with phases returning #<unspecified>.
But is there any guarantee that a Guile function returning #<unspecified> won't return, say, #f in later versions? If it does, there would be a bug in phases that don't add #t at the end.
