[plt-dev] reading symbols beginning with colon as keywords?

From: Matthew Flatt (mflatt at cs.utah.edu)
Date: Sun Jun 14 09:34:24 EDT 2009

At Sat, 13 Jun 2009 12:39:33 -0400, Neil Van Dyke wrote:
> How about symbols beginning with ":" be read as keywords, as if they 
> began with "#:"?
> I want to use keyword arguments in my libraries, but "#:" is big and 
> scary-looking, and a pain to type.

I don't think that "#:" is scary or a pain to type, and I like the way
that it stands out a bit. But I respect your opinion, and I know that
many others prefix a ":" prefix. Of course, there are also people who
feel that a ":" suffix is the only sensible choice.

(I don't know how big the various camps are. Just to satisfy my
curiosity, I'll take a poll on the plt-scheme list.)

I see no substantial technical advantage for any of the choices of
syntax, but there's a significant advantage in picking just one. All
else being equal, a single syntax makes the language easier to learn,
documentation easier to read, parsers easier to implement and extend,
etc. So, while I'm unsure that "#:" should be the syntax of keywords
forever, I'm sure that I don't want to support an additional ":" prefix
right now.

Posted on the dev mailing list.