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>>>>> higepon <higepon@xxxxxxxxx> writes: [...] >> Ultimately, the choice depends on the purpose of this srfi. If this >> one just wants to summarize "current practices", leave the behavior >> undefined and cross your fingers that it works "most of the time". >> If this one wants to provide a portable and robust basis, specify >> the behavior and encourage existing implementations to follow. I >> tend to vote the latter. > Thank you for your kind explanation. It was clear enough for me to > understand what you meant. > I want to summarize "current practices". So I suggest for keeping it > simple we summarize "current practices" in this srfi. It should be noted that `lookup-environment-variable' returns a byte-vector-like object, namely, an ``OS string'', in Scheme48. Despite the issues were already noted on the list, I'd like to quote a related comment: --cut: scheme48/scheme/rts/os-string.scm-- ; You may think that file names / environment variables / user names ; etc. are just text, but on most platforms, that assumption is wrong: ; They are usually NUL-terminated byte strings in some format. The ; bytes are invariant, but the corresponding text may depend on the ; locale. Also, byte sequences without a textual representation are ; possible. ; We assume that OS strings are encoded in some conservative extension ; of NUL-terminated ASCII. On Unix, this assumption pretty much has ; to hold true because of the various constraints of locale handling ; there. The Windows API uses an extension of UTF-16 that includes ; unpaired surrogates. For this, we use a synthetic extension of ; UTF-8 called UTF-8of16 that also deals with unpaired surrogates. --cut: scheme48/scheme/rts/os-string.scm-- It also means that the reference implementation given for Scheme48 is invalid (for Scheme48 after 1.3.) On the other hand, SLIB provides its `getenv' on top of `lookup-environment-variable' for both Scheme48 1.3 and higher, e. g.: http://cvs.savannah.gnu.org/viewvc/*checkout*/slib/scheme48.init?root=slib > Fortunately, your suggestion (c) is not inconsistent with simple one, > we can leave some rare cases to another srfi. [...]