viper-ALPHA-char-class is a variable defined in `viper-util.el'.
Its value is
"w"
Automatically becomes buffer-local when set.
Documentation:
String of syntax classes characterizing Viper's alphanumeric symbols.
In addition, the symbol `_' may be considered alphanumeric if
`viper-syntax-preference' is `strict-vi' or `reformed-vi'.
(buffer local)