On Tue, Jan 27, 2015 at 09:10:31AM +0100, Shawn Rutledge wrote: > On 26 January 2015 at 00:02, Matt Welland <mattrwell...@gmail.com> wrote: > > From http://wiki.call-cc.org/man/4/Using%20the%20interpreter the > ,commands are called "toplevel commands" and you can define them with: > > > > (toplevel-command SYMBOL PROC [HELPSTRING]) > > Where does this tradition come from? Is it related somehow to the use of > the comma as unquote inside a quasiquote?
I suppose so: at the toplevel, you can enter any expression, so for example just entering X will evaluate it. For that reason you'll need a special character to indicate that you're talking to the interpreter itself instead of evaluating something at the toplevel. You can't unquote anything outside a quasiquote expression, so it's kind of natural to use that as a prefix: it's one of the few undefined characters to use without adding additional restrictions to the lexical syntax of symbols, for example. > It always seems unintuitive to > me to start anything with a comma. I've gotten used to it already, but then I'd used vi for such a long time that starting a command with a colon seems "intuitive" to me also :) Cheers, Peter
signature.asc
Description: Digital signature
_______________________________________________ Chicken-users mailing list Chicken-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/chicken-users
