# Simplifying S-Expression Grammar

Supporting dots as part of identifiers and number literals, especially
at the beginning like in `...` or `.5`, but then special-casing a lone
dot for improper list syntax, is a bit annoying.

It makes my otherwise crystal clear and simple BNF grammar, as well as
my parser implementation, a bit less simple, which is bothersome.

Since I've already broken off heavily from traditional s-expressions,
I've decided to retire the dot as the improper list marker.  Instead
I'll be using the ampersand.

```
;; The good old
(foo bar . baz)

;; The new kid
(foo bar & baz)
```

This is way more annoying to type, and I've not yet gotten used to the
way it looks.  But you don't type improper lists frequently in code,
and I think the looks are just a matter of familiarity.

By the way, the ampersand is now illegal in identifiers.  It's totally
reserved for this singular purpose in the grammar.

The only common use I know of is exception types in R6RS, which I've
never liked anyway.  Using the question or exclamation marks would be
more intuitive, to express a questionable situation or a surprise!

I might walk back on this eventually, but so far it seems OK.