Re: Why should build phases not return unspecified values?

["Clément Lassieur" <clement@lassieur.org>]

Arun Isaac <arunisaac@systemreboot.net> writes:

> Alex Vong <alexvong1995@gmail.com> 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.