[asdf-devel] source file encoding

[Orivej Desh]

Douglas' main point may be transformed as follows, which is a legitimate
question: if the task is to extend the supported character set to UTF-8,
is not it solved by accepting :encoding option and defining default
#'encoding-external-format which understands (nothing but) :utf-8?
Given that, should the default be UTF-8 rather then :default?  Answering
`yes' might cause more or less trouble to some people, answering `no'
will provide for a gradual transition.  I think we should ask Zach Beane
about issues with unspecified and discerned external formats.

Another issue which somewhat bothers me: is such kind of a hook right?
It seems to be inherently unmanaged (just like *macroexpand-hook*),
i.e. setting it in a system affects future loaded systems, unless it is
set lexically in around-compile.  But then, it might as well be another
ASDF option (say, either a package designator which exports
#'encoding-external-format, or a list of a package and a keyworded
symbol designating desired function).  (By the way, I wouldn't call a
hooked function a hook, so that #'default-encoding-external-format-hook
would be #'default-encoding-external-format.)

The last issue relates to the strictness of the
default-encoding-external-format.  Probably it's all right, but then
wouldn't it be good to define a permissive alternative which behaves
like in 2.20.2?