Ticket #486 to make braces delimiters in R7RS failed for lack of a
second, so SRFI-105 needs to say explicitly that they are delimiters.
In particular, in the n-expression {foo}{bar baz} the implementation
must not treat "foo}{bar" as an identifier.

I mentioned this before but it seems to have gotten lost: I recommend
that [foo bar] in c-expressions be treated as ($bracket-list$ foo bar)
rather than (bracketaccess foo bar).  This is compatible with Kawa,
which is the only Scheme in my test suite to treat square brackets in
this way.  In FemtoLisp and Rep, they are used for vector datums; in
all other Schemes, they are synonyms for parentheses per R6RS, regular
identifier characters, or lexical syntax errors.

In any case, $bracket-list$ or bracketaccess should be specified as
being like nfx: no definition by default.

--
John Cowan  xxxxxx@ccil.org  http://ccil.org/~cowan
The competent programmer is fully aware of the strictly limited size of his own
skull; therefore he approaches the programming task in full humility, and among
other things he avoids clever tricks like the plague.  --Edsger Dijkstra