Concatenate strings - convenience wrapper?

Question

Is there a package that would extend the + operator with method for character types ( i.e. `+.character` <-function(x,y) {...} )?

In base R, writing this yields error:

"a" + "b" # Error in "a" + "b" : non-numeric argument to binary operator

What I would like to achieve is:

"a" + "b" #"ab"

I am aware of paste0("a","b"), but "a" + "b" is arguably more readable/shorter.

Of course there is always possibility to define special binary operator:

`%+%` <- function(x,y) paste0(x,y) "foo" %+% "bar" %+% "baz" # "foobarbaz"

character is a special class (it's also a type). It looks like + is hardcoded to give this error for character input and never calls the method in such a case. — Roland
– Roland, Commented May 13, 2015 at 11:15

zero323 · Accepted Answer · 2015-05-13 10:31:51Z

1

stringi provides %s+% operator:

> library(stringi) > "a" %s+% "b" [1] "ab"

and %stri+% operator:

> "a" %stri+% "b" [1] "ab"

answered May 13, 2015 at 10:31

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Comments

George Shimanovsky · Accepted Answer · 2019-08-07 12:53:42Z

In order to improve the readability of your code, you may enhance base + function so it would work like in Python:

"+" <- function(x, y) { if(is.character(x) || is.character(y)) { return(paste(x, y, sep = "")) } else { .Primitive("+")(x, y) } } "a" + "b" [1] "ab"