(string-mapconcat sequence separator . proc)

string-mapconcat returns a string concatenating the sequence after applying the optional procedure and separating the elements by separator.

Parameter	Description
sequence	The input list, vector, or string to operate on
separator	The separator character to introduce
proc	Optional: The procedure to apply to the sequence

Example

Example 1: As used in /modules/ln_core/string.scm

(if addr (string-mapconcat (u8vector->list addr) "." number->string) #f))