`substr_ctl<-`(txt4, 2, 2, terminate = FALSE, carry = TRUE, value = "#")

`substr_ctl<-`(txt4, 2, 3, terminate = FALSE, carry = TRUE, value = "#\033[32m?-")

`substr_ctl<-`(txt4, 2, 3, terminate = FALSE, carry = TRUE, value = "#\033[35m?-\033[0m")

`substr_ctl<-`(txt4, 2, 3, terminate = FALSE, carry = TRUE, value = "#\033[0m?-")

`substr_ctl<-`(txt4, 2, 3, terminate = FALSE, carry = TRUE, value = rep4)

## Reference for bridge against end of prior `value` substring

`substr_ctl<-`(txt5, 2, 2, value = ".\033[45m", carry = TRUE, 
    terminate = FALSE)

`substr2_ctl<-`(txt6, 2, 9, value = "\t", tabs.as.spaces = TRUE)

`substr2_ctl<-`(txt6, 2, 3, value = "\t", tabs.as.spaces = TRUE)

`substr2_ctl<-`(txt6, 2, 10, value = "\t", tabs.as.spaces = TRUE)

Encoding(`substr_ctl<-`(txt7a, 1, 1, value = val.scar))

Encoding(`substr_ctl<-`(txt7a, 1, 1, value = "s"))

Encoding(`substr_ctl<-`(txt7a, 2, 2, value = val.scar))

Encoding(`substr_ctl<-`(txt7a, 2, 2, value = "s"))

Encoding(`substr_ctl<-`(txt7b, 2, 2, value = val.scar))

Encoding(`substr_ctl<-`(txt7b, 2, 2, value = "s"))

Encoding(`substr_ctl<-`(txt7c, 3, 3, value = val.scar))

Encoding(`substr_ctl<-`(txt7c, 3, 3, value = "s"))

`substr_ctl<-`(txt2, 1, 3, terminate = FALSE, value = "#\033[32m?\033[0m")

## Include trail when selecting past end of `value`

## Only portions of string that are replaced are modified; leading and
## trailing controls remain, possibly causing redundant sequences when the
## lead and trail sequences are zero width, particularly with terminate=T.

`substr_ctl<-`(txt8, 1, 2, value = "12", terminate = FALSE)

`substr_ctl<-`(txt8, 1, 3, value = "\033[1m", terminate = FALSE)

Argument `carry` must be TRUE or FALSE in replacement mode.

[1] "Argument `carry` must be TRUE or FALSE in replacement mode."

tce(`substr_ctl<-`(lat, 1, 3, value = "ABC"))

`x` may only contain ASCII or marked UTF-8 encoded strings; you can use `enc2utf8` to convert `x` prior to use with `substr_ctl<-` (replacement form).  Illegal value at position [1].

[1] "`x` may only contain ASCII or marked UTF-8 encoded strings; you can use `enc2utf8` to convert `x` prior to use with `substr_ctl<-` (replacement form).  Illegal value at position [1]."

`substr_ctl<-`(txt.na2, 1, 1, value = "#")

`substr_ctl<-`(txt.nona, 1, 1, value = c("#", NA), carry = TRUE)