Re: New space char syntax

[Richard Stallman]

    Actually it isn't; I deliberately excluded `.' from the list of legal
    symbols which may immediately follow a character constant, since it
    is a legal symbol character, e.g:

This complication makes the question tricky; neither alternative
is entirely right.

    I can change it so that '(?a. ?b) is allowed,
    but then shouldn't '(?a.?b) be legal too?

I don't think so.  I think . should be allowed after the character
constant if it is a dotted-pair dot, but not if it starts a symbol.

    The parsing of the `.' token and lisp symbols is pretty obscure.
    Consider these examples:

Yike, this is horrible.

    I suggest to handle `;', `#', `[', and `?' as special
    characters when following a `.' just like `whitespace',
    `quote', `(' and `"' are today.

Those cases are simply bugs.  Thanks for identifying them.

    Finally, in a symbol, "`" and "," are not recognized as special 
    either, e.g.

            '(a`b,c) => (a\`b\,c)
            '(a`(b,c)) => (a\` (b\,c))

    I think the last example shows that they should be recognized.

It seems logical to handle them like singlequote.

    Also, if we fix that for symbols, the "`" and "," should be allowed
    after a character constant too, e.g.

            `(?a,xx)
            '(?a`(b,c))

I agree.