[sc34wg3] CTM: IRI pattern contest

[Lars Heuer]

Hi all,

In Leipzig we 'decided' (based on FCD comments) that we want an
explicit pattern for automatically detectable IRIs. These IRIs can be
used without the need to embed them into '<' / '>' brackets. I.e.
http://www.semagia.com would be detected as an IRI.

These IRIs are a bit special since they cannot end with a dot ('.') or
a semicolon (';')  (c.f. Oslo meeting notes [1])

I wonder if it wouldn't make sense to restrict the IRIs further:
- They shouldn't end with a "(" or a ")" because associations use them
  (and templates)
- They shouldn't end with a "," or ":" because roles use them
  (and templates)

I propose that these characters should not occur at the very end of an
IRI: ".", ";", ":", "(", ")", ","

Note: It is still possible make them part of the IRI if the IRI is
embedded into <>

Anyway, we need a good pattern for it, so any suggestion would be
helpful. Currently I use the following pattern (assuming that we
restrict the IRIs further as I've proposed):

    schema-name ::= [a-zA-Z]+[a-zA-Z0-9\+\-\.]*
    autodetectable-iri ::= schema-name '://'
((;|\.|\(|\)|,|:)*[^\s;\.\(\)\,:])+')

All characters may occur within the IRI but not at the very end (they
may appear at the end but they are not treated as part of the IRI).

I think TMQL needs something similar, so any simplification or
improvement would be helpful.

Here a little Python program which shows the results of the proposed pattern:

>>> import re
>>> pattern = re.compile(r'[a-zA-Z]+[a-zA-Z0-9\+\-\.]*://((;|\.|\(|\)|,|:)*[^\s;\.\(\)\,:])+')
>>> def matchiri(s):
	m = pattern.match(s)
	if m is None:
		print 'No match for <%s>' % s
	else:
		print 'Match: <%s>' % s[m.start():m.end()]

		
>>> matchiri('http://www.semagia.com;')
Match: <http://www.semagia.com>
>>> matchiri('http://www.semagia.com(foo')
Match: <http://www.semagia.com(foo>
>>> matchiri('http://www.semagia.com,')
Match: <http://www.semagia.com>
>>> matchiri('http://www.semagia.com)')
Match: <http://www.semagia.com>
>>> matchiri('http://www.semagia.com:')
Match: <http://www.semagia.com>
>>> matchiri('http://www.semagia.com:80')
Match: <http://www.semagia.com:80>
>>> matchiri('http://www.semagia.com.')
Match: <http://www.semagia.com>
>>> matchiri('http://www.semagia.com ')
Match: <http://www.semagia.com>
>>> matchiri('http://www.semagia.com(foo) ')
Match: <http://www.semagia.com(foo>
>>> matchiri('http://www.semagia.com)')
Match: <http://www.semagia.com>
>>> matchiri('http://www.semagia.com)foo')
Match: <http://www.semagia.com)foo>
>>>

So, Perl lovers and RegEx experts, your turn! :)

[1] <http://www.itscj.ipsj.or.jp/sc34/open/1023c.htm>

Best regards,
Lars
-- 
Semagia
<http://www.semagia.com/>