src/Pure/General/antiquote.ML

 fun split_lines input =
   let
     fun add a (line, lines) = (a :: line, lines);
     fun flush (line, lines) = ([], rev line :: lines);
     fun split (a as Text ss) =
-          (case take_prefix (fn ("\n", _) => false | _ => true) ss of
+          (case chop_prefix (fn ("\n", _) => false | _ => true) ss of
             ([], []) => I
           | (_, []) => add a
           | ([], _ :: rest) => flush #> split (Text rest)
           | (prefix, _ :: rest) => add (Text prefix) #> flush #> split (Text rest))
       | split a = add a;