Split string based on alternating character in R

Question

I\'m trying to figure out an efficient way to go about splitting a string like

\"111110000011110000111000\"

into a vector

[1] \         


        

Answer 1

You could probably make use of substr or read.fwf along with rle (though it is unlikely to be as efficient as any regex-based solution):

x <- "111110000011110000111000"
unlist(read.fwf(textConnection(x), 
                rle(strsplit(x, "")[[1]])$lengths, 
                colClasses = "character"))
#      V1      V2      V3      V4      V5      V6 
# "11111" "00000"  "1111"  "0000"   "111"   "000"

One advantage of this approach is that it would work even with, say:

x <- paste(c(rep("a", 5), rep("b", 2), rep("c", 7),
             rep("b", 3), rep("a", 1), rep("d", 1)), collapse = "")
x
# [1] "aaaaabbcccccccbbbad"

unlist(read.fwf(textConnection(x), 
                rle(strsplit(x, "")[[1]])$lengths, 
                colClasses = "character"))
#        V1        V2        V3        V4        V5        V6 
#   "aaaaa"      "bb" "ccccccc"     "bbb"       "a"       "d"