On 30/04/2008 2:44 AM, Martin Maechler wrote:
"DM" == Duncan Murdoch <[EMAIL PROTECTED]>
on Sat, 26 Apr 2008 17:21:06 -0400 writes:
DM> On 25/04/2008 2:47 PM, Prof Brian Ripley wrote:
>> On Fri, 25 Apr 2008, Deepayan Sarkar wrote:
>>
>>> For what it's worth, I use ?foo mostly to look up usage of functions
>>> that I know I want to use, and find it perfect for that (one benefit
>>> over help() is that completion works for ?). The only thing I miss is
>>> the ability to do the equivalent of help("foo", package = "bar");
>>> ?bar::foo gives the help page for "::". Perhaps that would be
>>> something to consider for addition.
>>
>> That fits most naturally with the (somewhat technical) idea that bar::foo
>> becomes a symbol and not a function call. I believe that several of think
>> that is in principle a better idea, but no one has as yet (AFAIK) explored
>> the ramifications.
>>
>> However, 5 mins looking at the sources suggests that it is easy to do.
DM> And you already did. Thanks!
indeed.
DM> I'm going to make the following change soon (in R-devel).
DM> ??foo
DM> will now be like help.search("foo"). This will work with your change,
DM> so ??utils::foo will limit the search to the utils package. This is
DM> also quite easy. A more difficult thing I'd like to do is to broaden
DM> the search to look outside the man pages, but that's a lot harder, and I
DM> haven't started on it.
DM> I will also follow Hadley's suggestion and change the format of the
DM> help.search results, so you can just cut and paste after a question mark
DM> to look up the particular topic, e.g. ??foo gives
DM> utils::citEntry Writing Package CITATION Files
DM> Type '?PKG::FOO' to inspect entry 'PKG::FOO TITLE'.
DM> I haven't touched the case of ?foo failing; I'll want to try it for a
DM> while to decide whether I like it best as is:
>> ?foo
DM> No documentation for 'foo' in specified packages and libraries:
DM> you could try '??foo'
DM> or whether it should just automatically call help.search, or something
DM> in between.
Please the former, at least by default!
[The case of 1500 installed packages was mentioned before...]
Note one thing that hasn't been mentioned before:
help() has had the optional argument
' try.all.packages = getOption("help.try.all.packages") '
for many years now, and I have been involved in its history as
well but don't recall all details. IIRC,
help() {and hence "?"} used to *default* to
'try.all.packages = TRUE' for a while and later it was the
default for me (and our whole statistics departmental unit).
But we found that it *was* inconvenient that a big search was
started, often just because of a typo.
So I think ?<non-existing> should ``answer quickly'' by
default.
Have you tried help.search() lately? It is now very fast. I haven't
checked if help() makes use of the same search mechanism, but presumably
it could do so, if speed is an issue.
So I would say the speed is a solvable or solved problem.
Duncan Murdoch
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