[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
whether #!identifiers are datums
This isn't very relevant to SRFI 103, but it comes up
from time to time.
Derick Eddington wrote:
> I thought #!identifier lexical tokens are considered comments at a level
> below "syntactic datums". I, of course, meant the first thing the
> standard read procedure would return. I thought calling that a "datum"
> was the normal terminology.
#!r6rs is the only lexical token of that form that is
guaranteed to be a comment. Tokens such as #!undefined
and #!eof are unlikely to be comments in implementations
that support such things.
In R6RS systems, whether implementation-dependent directives
like #!fold-case and #!no-fold-case are comments is also
implementation-dependent. In ERR5RS, those directives are
datums, not comments, and apply only to the port from which
they are read; if someone wants to change the case-folding
mode for a port without adding a datum, one of those tokens
can be preceded by a #; token. See the end of