Q: how to start a module name with a lower case character?

Ruby
1

I am trying to write Ruby classes to model RDF, RDFS, and Owl, much
like SWCLOS does for Common Lisp:

module Rdfs
…
end

x = Rdfs::Class.new(Rdfs::Label => “label_1”)

It would be nice to have a hack that would allow module names to start
with a lower case letter. Any ideas?

It would also be good to be able to alias “::” to “:” so that I could
use a syntax like:

rdfs:Label

Any ideas and references to things to read, no matter how hack-like,
will be appreciated.

2

On 6/25/07, Mark W. [email protected] wrote:

It would be nice to have a hack that would allow module names to start

I can think of two hacks, one to get lowercase module names, and one to
get
a single colon, but they aren’t compatible with each other:

Lowercase module name:

rdfs = Module.new do
… code …
end

(Note that rdfs is a local variable, with all the attendant scoping
issues)

rdfs:Label syntax:

module Rdfs
… code …
end

def rdfs( name )
Rdfs.const_get(name)
end

rdfs:Label # yuck

You know if you really want to make look just like the syntax you want,
you
can use strings. I would not recommend abusing ruby to the extent you
would
have to almost acheive what you want.

3

On 25.06.2007 16:53, Mark W. wrote:

with a lower case letter. Any ideas?
You can’t because module names must be constants and constants have to
start with an uppercase letter.

It would also be good to be able to alias “::” to “:” so that I could
use a syntax like:

rdfs:Label

Hm, no idea whether there is a way although Ruby seems to accept the
syntax:

$ ruby -ce ‘rdfs:Label’
Syntax OK

Kind regards

robert

4

Robert K. wrote:

On 25.06.2007 16:53, Mark W. wrote:
[snip]

It would also be good to be able to alias “::” to “:” so that I could
use a syntax like:

rdfs:Label

Hm, no idea whether there is a way although Ruby seems to accept the syntax:

$ ruby -ce ‘rdfs:Label’
Syntax OK

FWIW, this is because Ruby interprets that as a method call with a
symbol argument, i.e. rdfs( :Label )

irb(main):002:0> rdfs:Label
NoMethodError: undefined method `rdfs’ for main:Object
from (irb):2
irb(main):003:0> def rdfs( *args ) p args end
=> nil
irb(main):004:0> rdfs:Label
[:Label]

So, with predefined or dynamic prefixes, you could use that syntax as
a method that returns a specially-namespaced constant.

5

On 6/25/07, Robert K. [email protected] wrote:

Hm, no idea whether there is a way although Ruby seems to accept the syntax:

$ ruby -ce ‘rdfs:Label’
Syntax OK

Incase it wasn’t clear what was going on in Logan’s post, the reason
why that syntax is okay is because it’s interpreted as rdfs(:Label)