> What about opening an ASCII coded file? Can emacs > properly detect it or does it come up as UTF-8?
Emacs attempts to determine the correct coding system when it opens a file, so you shouldn't have to worry about this.
The 128 characters that make up ASCII have the exact same representation in UTF-8. "Converting" as ASCII file to UTF-8 is a no-op. Therefore, treating an ASCII file as UTF-8 should cause no problems.
> I assume that if my lisp library files are encoded utf-8, then I can > paste that UTF-8 character from the web page into my call to > (replace-string ...) in order to substitute the longer dash of Unicode
> U+2013 with an ASCII hyphen or double hyphen. But, how does that really > work? If the lisp file is encoded utf-8, then how can I put an ASCII > character in the replacement string? Or do I need to encode the hex
> value of the ASCII character(s)?
A = A. The hyphen-minus is a hyphen-minus whether it's in an ASCII file as 00101101 or a UTF-16 file as 0000000000101101. So, just type it with your keyboard.
BTW, I don't know how Xah intended it, but when he said to "embrace unicode," I interpreted it to mean, "Why don't you just leave em-dashes as em-dashes instead of replacing them with two hyphen-minuses?"
-- -PJ
Gehm's Corollary to Clark's Law: Any technology distinguishable from magic is insufficiently advanced.