Re: [bug]Malformed -*- line

[Kenichi Handa]

In article <address@hidden>, CHENG Gao <address@hidden> writes:

> I bashfully confess I do read manual.

Have you read Elisp info?   This section describes about
"&optional" argument list.

12.2.3 Other Features of Argument Lists
---------------------------------------

[...]
   If actual arguments for the optional and rest variables are omitted,
then they always default to `nil'.  There is no way for the function to
distinguish between an explicit argument of `nil' and an omitted
argument.  However, the body of the function is free to consider `nil'
an abbreviation for some other meaningful value.  This is what
`substring' does; `nil' as the third argument to `substring' means to
use the length of the string supplied.


---
Kenichi Handa
address@hidden