Re: Prefix, not postfix (poll)

[Per Bothner <per@bothner.com>]

Marc Feeley wrote:
> My feeling is that the colon character does not belong in symbols anyway 
> (either in the middle or at the end).  It should be reserved as an infix 
> operator to denote a qualified reference to a module (i.e. foo:bar 
> should mean the thing called bar in the module foo).  Many programming 
> languages use such a notation, and in fact many Scheme programs use this 
> notation for their own 90%-solution modules.

Kawa uses colon more generally as a "component-extraction" operator.
See http://www.gnu.org/software/kawa/PathExpressions.html
Basically the reader translates
  expression:name
to:
  ($lookup$ expression 'name)
and then the $lookup$ operation does the appropriate thing depending on
the type of expression.  This includes Java field and method lookup,
and namespace/package lookup.  There are various compile-type
optimizations, plus some kludges for quoting, and for backwards
compatibility with code that uses colons in identifiers.

It's a more general and elegant solution (in my not-so-humble
opinion, of course) than the "JavaDot" notation used in some other
Java-based Scheme implementations.
--
	--Per Bothner
per@bothner.com   http://per.bothner.com/