Example Usage

In charcuterie: Handle Strings as Vectors of Characters

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

With strings encoded as a vector of characters, we can perform vector operations over the actual characters. All {charcuterie} functions aim to return a new object of class "chars" so it is also able to be printed as a string and passed to other vector-handling functions.

library(charcuterie)

To convert a regular string into a chars object, use chars(). This prints as a string, but is actually a vector

chars("string")

# but it's a vector
unclass(chars("string"))

Only a single string can be converted this way, so if you want to produce more than one of these, I suggest

many_chars <- lapply(c("foo", "bar", "baz"), chars)
many_chars
unclass(many_chars[[2]])

A regular string can be recovered using string() which pastes the characters back together

string(chars("string"))

and this can optionally take a separator

string(chars("string"), collapse = "|")

Because the chars object is a vector we can do vector things, such as indexing

"string"[3] # doesn't work

chars("string")[3]
chars("banana")[seq(2, 6, 2)]

subsetting

head("string", 3) # doesn't work

head(chars("string"), 3)
tail(chars("string"), 3)

substituting

word <- chars("string")
word[3] <- "R"
word

tabulating

table("mississippi") # doesn't work

table(chars("mississippi"))

sorting

sort("string") # doesn't work

sort(chars("string"))
sort(chars("string"), decreasing = TRUE)

reversing

rev("string") # doesn't work

rev(chars("string"))

Since these are vectors, we no longer need nchar to determine the length

length("string") # just the one 'string'

length(chars("string")) == nchar("string")

Membership tests can now determine if a given character is in the 'string'

"i" %in% "rhythm" # doesn't work
"y" %in% "rhythm" # doesn't work

"i" %in% chars("rhythm")
"y" %in% chars("rhythm")

is.element("y", "rhythm") # doesn't work

is.element("y", chars("rhythm"))

chars objects can be concatenated; combining two strings produces a longer string

c("butter", "fly") # doesn't work in the character sense

c(chars("butter"), chars("fly"))
c(chars("butter"), chars("fly"))[c(1, 9)]

Set operations can be useful

setdiff(chars("javascript"), chars("script"))
union(chars("bunny"), chars("rabbit"))
intersect(chars("bob"), chars("rob"))
setequal(chars("stop"), chars("post"))
setequal(chars("stop"), chars("posit"))
unique(chars("mississippi"))

Since chars objects are regular vectors, they continue to work with other vectorised operations

rev(toupper(chars("string")))
toString(chars("abc"))

Filter(\(x) x != "a", "banana")
Filter(\(x) x != "a", chars("banana"))

This last example motivates a non-set-wise way to exclude some characters, so this package introduces a new except function

except(chars("javascript"), chars("script"))
except(chars("carpet"), chars("car"))
except(chars("banana"), "a")
except(chars("banana"), chars("a"))

Anywhere a vector of individual character works, a chars object should also work

data.frame(number = 1:3, letter = chars("abc"))

charcuterie documentation built on April 3, 2025, 8:53 p.m.