str_replace_all errors with multiple matches, a named `string` vector, and a function `replacement`

[hughjonesd]

The first call below errors. The others are fine.

# Named arguemnt
stringr::str_replace_all(c(name = "string string"), "string", function (x) rep("strong", length(x)))
Error in `vctrs::list_unchop()`:
! Can't merge the outer name `name` with a vector of length > 1.
Please supply a `.name_spec` specification.
Run `rlang::last_trace()` to see where the error occurred.

Enter a frame number, or 0 to exit   

1: stringr::str_replace_all(c(name = "string string"), "string", function(x) rep("strong",
2: str_transform_all(string, pattern, replacement)
3: vctrs::list_unchop(old)
4: abort(message = message)
5: signal_abort(cnd, .file)

Selection: 0

# Unnamed argument
stringr::str_replace_all(c("string string"), "string", function (x) rep("strong", length(x)))
[1] "strong strong"

# Character replacement
stringr::str_replace_all(c(name = "string string"), "string", "strong")
           name 
"strong strong" 

# Single match
stringr::str_replace_all(c(name = "string"), "string", function (x) rep("strong", length(x)))
[1] "strong"

This is (I think) new in 1.6.0.

[allenbaron]

FYI: I'm not a maintainer here. I just happened across this while trying to figure out something else.

This error occurs only when a replacement function is used because that's when the internal str_transform_all() is called:

stringr/R/replace.R

Lines 107 to 116 in ae054b1

	str_replace_all <- function(string, pattern, replacement) {
	if (!missing(replacement) && is_replacement_fun(replacement)) {
	replacement <- as_function(replacement)
	return(str_transform_all(string, pattern, replacement))
	}
	if (!is.null(names(pattern))) {
	vec <- FALSE
	replacement <- unname(pattern)
	pattern[] <- names(pattern)

... and str_transform_all() uses vctrs::list_unchop() which requires the name_spec argument to handle names or errors, as you've shown.

stringr/R/replace.R

Lines 220 to 232 in ae054b1

	str_transform_all <- function(
	string,
	pattern,
	replacement,
	error_call = caller_env()
	) {
	locs <- str_locate_all(string, pattern)
	old <- str_sub_all(string, locs)
	# unchop list into a vector, apply replacement(), and then rechop back into
	# a list
	old_flat <- vctrs::list_unchop(old)

It could be fixed by just dropping names, e.g. vctrs::list_unchop(old, name_spec = rlang::zap()). Or really adding anything that works there probably because it works fine with unlist(old) instead.