Depreciating partial matching

Le jeudi 21 mars 2013 ? 08:51 -0500, Terry Therneau a ?crit :

I am not in favor of the change, which is a choice of rigor over usability.

When I am developing code or functions I agree with this, and I view any warnings from R
CMD check about shortened arguments as positive feedback.

But 90% of my usage of R is day to day data analysis, interactive, at the keyboard.  A lot
of data sets that come to me have long variable names.  What this change will mean to me
is that I'll either spend a lot of time cursing at these annoying frickin warnings, or
have to take the time to make new data sets (several times a week) that have abbreviated
names.  Of course when I come back to that project 8 weeks later I'll need to recreate the
short-long mapping in my head...

Let's think about WHY abbreviated names were allowed in the first place.  Usability is
worth a lot more than purity to the actual users of a package.  S had the rare advantage
of serious users just down the hall from the developers, which I hypothesise is one of the
true foundation for it's success.  (What user would have invented the hiding aspect S4
classes --- "let's put the results of the fit into a steel box so they can't see the
parts" --- which is actually touted as a virtue?  I cringe every time a new method I need
is sewed up this way.)

"C is a remarkable language.  ... The success of C is due to a number of factors, none of
them key, but all of them important. Perhaps the most significant of all is that C was
developed by real practioners of programming and was designed for practical day-to-day
use, not for show or for demonstration. Like any well-designed tool, it falls easily to
the hand and feels good to use. Instead of providing constraints, checks and rigorous
boundaries, it concentrates on providing you with power and on not getting in your way."
     Preface to "The C Book", M Banahan et al

I would think that the ability to hit the Tab key to trigger name
completion in your R GUI makes partial matching almost useless. The
avantage of interactive completion in the GUI is that you immediately
see the result of the partial matching. So you get the best of both
worlds: no need to type long variable names in full, but no traps when a
match is not what you would expect.

Doesn't this suit your use case?

Regards

Terry Therneau


On 03/21/2013 06:00 AM, r-devel-request at r-project.org wrote:

Allowing partial matching on $-extraction has always been a source of accidents.
Recently, someone who shall remain nameless tried names(mydata)<- "d^2" followed by
mydata$d^2. As variables in a data frame are generally considered similar to variables
in, say, the global environment, it seems strange that foo$bar can give you the content
of foo$bartender. In R-devel (i.e., *not* R-3.0.0 beta, but 3.1.0-to-be) partial matches
now gives a warning. Of course, it is inevitable that lazy programmers will have been
using code like

	[[alternative HTML version deleted]]