[Rd] "+" operator on characters revisited

[Vitalie S.]

Hello everyone!

Motivated by the recent post on SO
http://stackoverflow.com/questions/4730551/making-a-string-concatenation-operator-in-r

I wonder what is the current state of argument on making "+" to
concatenate character vectors. The "+" method is still sealed for
signature("character", "character") in the current version of R.

The 4 years old R-devel thread
https://www.stat.math.ethz.ch/pipermail/r-devel/2006-August/038991.html
on the same topic, stopped without reaching any definite conclusion.

The only definite argument occurred in the thread against "+" operator
was the lack of commutativity (as if one have to prove algebraic
theorems in R).

Yet another useful suggestion of introducing cat0() and paste0(), for
the common use of cat and paste with sep="" was not absorbed by the
core R either.

Thanks,
Vitalie