···19 else op (head list) (fold op nul (tail list));
20210000022 # Concatenate a list of strings.
23 concatStrings =
24 fold (x: y: x + y) "";
···19 else op (head list) (fold op nul (tail list));
202122+ # Concatenate a list of lists.
23+ concatLists =
24+ fold (x: y: x ++ y) [];
25+26+27 # Concatenate a list of strings.
28 concatStrings =
29 fold (x: y: x + y) "";