check-code: introduce function for using re2 when available
Do it similar as in mercurial.util. For simplicity only support flag
multiline which is the only one used.
from mercurial.hg import parseurl
def testparse(url, branch=[]):
print '%s, branches: %r' % parseurl(url, branch)
testparse('http://example.com/no/anchor')
testparse('http://example.com/an/anchor#foo')
testparse('http://example.com/no/anchor/branches', branch=['foo'])
testparse('http://example.com/an/anchor/branches#bar', branch=['foo'])
testparse('http://example.com/an/anchor/branches-None#foo', branch=None)
testparse('http://example.com/')
testparse('http://example.com')
testparse('http://example.com#foo')