How to separate a string from a certain line of a data.frame and at the same time create more lines?

Question:

I have a data.frame with a column with strings like "123-235-203".

For example, the line:

string column1 column2
123-235-203 xy

I want to separate this string, so that the line that contains it is multiplied, preserving the values ​​of the other columns:

strsplit(string, "-")

Turning the line into 3 lines.

string column1 column2
123 xy
235 xy
203 xy

Is there a way to do this using dplyr or tidyr?

Answer:

Hadley himself offers us the answer in the tidyr vignette.

library(tidyr)
library(dplyr)
df <- data.frame(
x = 1:3,
y = c("a", "d,e,f", "g,h"),
stringsAsFactors = FALSE
)
df %>%
transform(y = strsplit(y, ",")) %>%
unnest(y)