[Rd] Improving string concatenation

[William Dunlap]

> ... adding the ability to concat
> strings with '+' would be a relatively simple addition (no pun intended)
to
> the code base I believe. With a lot of other languages supporting this
kind
> of concatenation, this is what surprised me most when first learning R.

Wow!  R has a lot of surprising features and I would have thought
this would be quite a way down the list.

How would this new '+' deal with factors, as paste does or as the current
'+'
does?  Would number+string and string+number cause errors (as in current
'+' in R and python) or coerce both to strings (as in current R:paste and
in perl's '+').

Having '+' work on all types of data can let improperly imported data
get further into the system before triggering an error.  I see lots of
errors
reported on this list that are due to read.table interpreting text as
character
strings instead of the numbers that the user expected.  Detecting that
error as early as possible is good.



Bill Dunlap
TIBCO Software
wdunlap tibco.com

On Tue, Jun 16, 2015 at 10:25 PM, Joshua Bradley <jgbradley1 at gmail.com>
wrote:

> Bad choice of words I'm afraid. What I'm ultimately pushing for is a
> feature request. To allow string concatenation with '+' by default. Sure I
> can write my own string addition function (like the example I posted
> previously) but I use it so often that I end up putting it in every script
> I write.
>
> It is ultimately a matter of readability and syntactic sugar I guess. As an
> example, I work in the bioinformatics domain and write R scripts for
> pipelines with calls to various programs that require a lot of parameters
> to be set/varied. Seeing "paste" everywhere detracts from reading the code
> (in my opinion).
>
> This may not be a very strong argument, but to give a bit more objective
> reason, I claim its more readable/intuitive because other big languages
> have also picked up this convention (C++, java, javascript, python, etc.).
>
>
> Josh Bradley
> Graduate Student
> University of Maryland
>
> On Tue, Jun 16, 2015 at 11:00 PM, Gabriel Becker <gmbecker at ucdavis.edu>
> wrote:
>
> >
> > On Jun 16, 2015 3:44 PM, "Joshua Bradley" <jgbradley1 at gmail.com> wrote:
> > >
> > > Hi, first time poster here. During my time using R, I have always found
> > > string concatenation to be (what I feel is) unnecessarily complicated
> by
> > > requiring the use of the paste() or similar commands.
> >
> > I don't follow. In what sense is paste complicated to use? Not in the
> > sense of it's actual behavior, since what you propose below has identical
> > behavior. So is your objection simply the number of characters one must
> > type?
> >
> > I would argue that having a separate verb makes code much more readable,
> > particularly at a quick glance. I know a character will come out of paste
> > no matter what goes in. That is not without value from a code maintenance
> > perspective. IMHO.
> >
> > ~G
> >
> > >
> > >
> > > When searching for how to concatenate strings in R, several top search
> > > results show answers that say to write your own function or override
> the
> > > '+' operator.
> > >
> > > Sample code like the following from this
> > > <
> >
> http://stackoverflow.com/questions/4730551/making-a-string-concatenation-operator-in-r
> > >
> > > page
> > >
> > > "+" = function(x,y) {
> > >     if(is.character(x) & is.character(y)) {
> > >         return(paste(x , y, sep=""))
> > >     } else {
> > >         .Primitive("+")(x,y)
> > >     }}
> > >
> > >
> > >
> > > An old (2005) post
> > > <https://stat.ethz.ch/pipermail/r-help/2005-February/066709.html> on
> > r-help
> > > mentioned possible performance reasons as to why this type of string
> > > concatenation is not supported out of the box but did not go into
> detail.
> > > Can someone explain why such a basic task as this must be handled by
> > > paste() instead of just using the '+' operator directly? Would
> > performance
> > > degrade much today if the '+' form of string concatenation were added
> > into
> > > R by default?
> > >
> > >
> > >
> > > Josh Bradley
> > >
> > >         [[alternative HTML version deleted]]
> > >
> > > ______________________________________________
> > > R-devel at r-project.org mailing list
> > > https://stat.ethz.ch/mailman/listinfo/r-devel
> >
>
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>
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