Available since: Gideros 2016.06
Returns a copy of s in which all (or the first n, if given) occurrences of the pattern have been replaced by a replacement string specified by repl, which can be a string, a table, or a function. gsub also returns, as its second value, the total number of matches that occurred. The name gsub comes from Global SUBstitution. If repl is a string, then its value is used for replacement. The character % works as an escape character: any sequence in repl of the form %d, with d between 1 and 9, stands for the value of the d-th captured substring. The sequence %0 stands for the whole match. The sequence %% stands for a single %. If repl is a table, then the table is queried for every match, using the first capture as the key. If repl is a function, then this function is called every time a match occurs, with all captured substrings passed as arguments, in order. In any case, if the pattern specifies no captures, then it behaves as if the whole pattern was inside a capture. If the value returned by the table query or by the function call is a string or a number, then it is used as the replacement string; otherwise, if it is false or nil, then there is no replacement (that is, the original match is kept in the string).
(string), (number) = utf8.gsub(s,pattern,repl,n)
n: (number) optional
Returns (string) replaced string
Returns (number) number of substitutions