str_coalesce: Coalesce character vectors

In cheapr: Simple Functions to Save Time and Memory

Coalesce character vectors

Description

str_coalesce() find the first non empty string "". This is particularly useful for assigning and fixing the names of R objects.

In this implementation, the empty string "" has priority over NA which means NA is only returned when all values are NA, e.g. str_coalesce(NA, NA).

Usage

str_coalesce(..., .args = NULL)

Arguments

...	Character vectors to coalesce.
.args	An alternative to ... for easier programming with lists.

Details

str_coalesce(x, y) is equivalent to if_else(x != "" & !is.na(x), x, y).

Value

A coalesced character vector of length corresponding to the recycled size of supplied character vectors. See ?recycle for details.

Examples

library(cheapr)

# Normal examples
str_coalesce("", "hello")
str_coalesce("", NA, "goodbye")

# '' always preferred
str_coalesce("", NA)
str_coalesce(NA, "")

# Unless there are only NAs
str_coalesce(NA, NA)

# `str_coalesce` is vectorised

x <- val_insert(letters, "", n = 10)
y <- val_insert(LETTERS, "", n = 10)

str_coalesce(x, y)

# Using `.args` instead of `do.call` is much more efficient
library(bench)
x <- cheapr_rep_len(list(letters), 10^3)

mark(do.call(str_coalesce, x),
     str_coalesce(.args = x),
     iterations = 50)

cheapr documentation built on June 8, 2025, 11:35 a.m.