clarity in a unicode world

2.2: adda/clarity in a unicode world:
oreilly commenters mention rust:
. Rust is Mozilla's new lower-level language;
it has a policy of ASCII-only lexemes.
. all platforms have Unicode libraries,
so why go ASCII-only ?  [2.9:
At the moment it’s just a matter of
keeping the lexer simple
(no character-class tables to consult)
as well as making it accessable to all unix tools .]

. I first conjectured ASCII-only was for security:
it's for the same reason that
website names should be ascii;
if you have 2 names that look the same,
but one uses european letters,
then people could get them confused .
. the question for a lang then is
how can the compiler give writers freedom
and still help readers stay unconfused?
# highlighting:
. whenever non-ascii could be confused with ascii,
it would be in a contrasting font or style .
# substitution:
. the editor makes it easy to
change variable names:
after parsing, a name is identified as a var';
and, the var links to its scope,
so, after a user has changed the var's name,
the entire text for that scope is re-displayed
so that all instances of the var's name
reflect the user's preference .

integrate with translations:
. like chrome.browser is integrated with
google-translate,
have the editor translate any foreign characters
to the user's {alphabet, vocabulary} .