Re: [PATCH v3] kconfig: sort found symbols by relevance

[Wang YanQing <udknight@gmail.com>]

On Thu, May 09, 2013 at 06:12:17PM +0200, Yann E. MORIN wrote:
> Wang, All,
> 
> On Thu, May 09, 2013 at 11:27:31PM +0800, Wang YanQing wrote:
> > On Mon, May 06, 2013 at 11:15:31PM +0200, Yann E. MORIN wrote:
> > > From: "Yann E. MORIN" <yann.morin.1998@free.fr>
> > > 
> > > When searching for symbols, return the symbols sorted by relevance.
> > > 
> > > Sorting is done as thus:
> > >   - first, symbols with a prompt,   [1]
> > >   - then, smallest offset,          [2]
> > >   - then, shortest match,           [3]
> > >   - then, highest relative match,   [4]
> > >   - finally, alphabetical sort      [5]
> > > 
> > > So, searching (eg.) for 'P.*CI' :
> > > 
> > > [1] Symbols of interest are probably those with a prompt, as they can be
> > >     changed, while symbols with no prompt are only for info. Thus:
> > >         PCIEASPM comes before PCI_ATS
> > 
> > Search the value of symbols with no prompt are useful too
> 
> My reasonning here is that often I need to toggle a symbol, but am not
> sure what menu it's in, so I search for it.
> 
> Sometime, I also need to search for prompt-less symbols, too, to see why
> a symbol I want is not visible. But that's not the most common use-case.
> 
> Also, the examples provided were with a very verbose search: 'P.*CI'
> which is expected to return a hell of a lot of symbols. More precise
> searches will yield substancially fewer symbols, so the search results
> will probably fit in 1 or 2 pages, not 10+ like 'P.*CI'
> 
> > > [2] Symbols that match earlier in the name are to be preferred over
> > >     symbols which match later. Thus:
> > >         PCI_MSI comes before WDTPCI
> > 
> > We can achieve this with ^PCI regular search
> 
> Yes, but I expect users do enter the begining of symbols, not a string
> in the middle or at the end.
> 
> Also, as Jean and Thomas have proven, not many people know that searches
> can be regular expressions.

Ok, indeed, I don't know regular expression in menuconfig before you
point it out :)

> > > [3] The shortest match is (IMHO) more interesting than a longer one.
> > >     Thus:
> > >         PCI comes before PCMCIA
> > 
> > We can achieve this with ^PCI regular search plus your previous heuristic
> 
> This one is not about location of the match, it's about the length of
> the match: the shortest the match, the more interesting it is (IMHO). So
> we'd prefer FOO_PCI_BAR_BUZ over A_PACI_B  (when searching for 'P.*CI').

Ok, I get your meaning.

> > > [4] The relative match is the ratio of the length of the match against
> > >     the length of the symbol. The more of a symbol name we match, the
> > >     more instersting that symbol is. Thus:
> > >         PCIEAER comes before PCIEASPM
> > 
> > This is what your first heuristic
> > 
> > > [5] As fallback, sort symbols alphabetically
> > This is in your first heuristic too.
> > 
> > > This heuristic tries hard to get interesting symbols first in the list.
> > I don't mean your this heuristic is bad, but
> 
> This heuristic is just that: a heuristic. It kicks in only if the user
> dit not provide an anchored regexp (ie with start- or end-of-line).
> 
> For the ten-or-so tests I did, the sorting was rather appropriate,
> though that's only ten-or-so tests and is not exhaustive (and probably
> subject to testing bias, too).

I hope more people will find the sorting is appropriate if Michal Marek accept 
it :)

> What I'm trying to achieve here is come up with a way to sort symbols
> for searches of *non-anchored* regexps. Anchored regexps will always
> provide the results they used to provide so far.
> 
> Maybe we can emphasize in the UI the fact that regexps, and especially
> anchored regexps, can be used.
> 
> > maybe provide mechanism to user will make guesser life easier.
> 
> Sorry, I can't make sense of this sentence. :-( Can you elaborate a bit
> what you meant, please?

The mechanism means first heuristic in previous Email patch.

I though we could get this heuristic's result by composite your first heuristic
in previous Email patch with regular expression, it seams like I lost something,
see above.

Thanks.