OK, so I think it's worth it adding automatic detection to ASDF and making it the default. However, before I merge anything into ASDF itself, I'd like to see it implemented as part of asdf-encodings. This will also make it easier to experiment with various approaches and see which works best while leading to maintainable code. I admit I like pjb's approach of heeding the emacs declaration of coding: it's consistent with the Lisp tradition, compatible with an existing productivity tool (emacs), and can be re-used for more features.
From a cursory glance, I'm not convinced by his specific implementation; it seems to me the thing could be cleaner. When no encoding is specified, autodetection can be used as per Douglas's code, with latin-1 and/or whatever 8-bit default is available as a fallback if it's not UTF-8.
Then, maybe the plan should be for 2.21 to add the :encoding keyword, but keep :default as the default for now, to be changed to either :utf-8 or :autodetect when the dust has settled. People who want to get deterministic utf-8 behavior can then use #+asdf-unicode #+asdf-unicode :encoding :utf-8 for now. —♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org Wealth, like happiness, is never attained when sought after directly. It comes as a by-product of providing a useful service. — Henry Ford