On Fri, Oct 11, 2013 at 1:47 AM, John Cowan <[email protected]> wrote:
> Michael Montague scripsit: > > > The lexical rules given in 7.1.1 do not allow #\@ as the initial > > character of an identifier. One of the quasiquote examples and the note > > above, assume that identifiers can start with #\@. > > > > I assume that the lexical rules are correct and #\@ is not allowed as an > > initial character of an identifier. > > It is not allowed in the standard language. However, it is a legitimate > implementation extension to the lexical syntax, in which case the note > in 4.2.8 applies. > Actually, this was ticket #12 in the second ballot, which sides with the prose in section 2.1: An identifier is any sequence of letters, digits, and "extended identifier characters" provided that it does not have a prefix which is a valid number. The formal syntax was updated partially to allow identifiers beginning with - or +, but <special initial> was not updated to include additional ASCII characters. I believe @ is the only character missing from that list. @ in particular is important because it makes the SSAX syntax retroactively valid. -- Alex
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