[PATCH 3 of 7 V3 RFC] parser: move alias declaration parser to common rule-set class

[Yuya Nishihara]

On Sun, 3 Apr 2016 14:04:20 -0700, Pierre-Yves David wrote:
> On 04/03/2016 02:48 AM, Yuya Nishihara wrote:
> > # HG changeset patch
> > # User Yuya Nishihara <yuya at tcha.org>
> > # Date 1456736043 -32400
> > #      Mon Feb 29 17:54:03 2016 +0900
> > # Node ID aa54435b4a485541d3be7abbe5ed6fd584b43ee5
> > # Parent  37cbd68f6cd8760b146570dd8b547589539605fd
> > parser: move alias declaration parser to common rule-set class
> >
> > The original _parsealiasdecl() function is split into common _builddecl()
> > and revset-specific _parsealiasdecl(). And the original _parsealiasdecl()
> > call is temporarily replaced by rules._builddecl(), which should be eliminated
> > later.
> >
> > The doctests are mostly ported by using the dummy parse(), but the test for
> > 'foo bar' is kept in _parsealiasdecl() as it checks if "pos != len(decl)" is
> > working. Also, 'foo($1)' test is added to make sure the alias tokenizer can
> > handle '$1' symbol, which is the only reason why we need _parsealiasdecl().
> >  
> 
> […]
> 
> > @@ -2373,6 +2316,7 @@ def _parsealiasdefn(defn, args):
> >   class _aliasrules(parser.basealiasrules):
> >       """Parsing and expansion rule set of revset aliases"""
> >       _section = _('revset alias')
> > +    _parsedecl = staticmethod(_parsealiasdecl)
> >       _getlist = staticmethod(getlist)
> >
> >   class revsetalias(object):  
> 
> Why are we keeping the function outside of the class? (With a manual
> staticmethod promition and assignement). Shouln't we be able to directly
> declare it inside the class with a @static method decorator?

Two reasons:

 a) It's paired with _tokenizealias(). I could move both _parsealiasdecl()
    and _tokenizealias() to _aliasrules, but it would introduce unnecessary
    name "_tokenize" under _aliasrules, which I didn't want to.

 b) _parsealiasdecl() is only a parser that takes '$' as a symbol char, which
    can theoretically be used as one of parsing functions.