src/Pure/PIDE/yxml.scala
2012-08-29 ago clarified separated_chunks vs. space_explode;
2011-11-29 ago separate compilation of PIDE vs. Pure sources, which enables independent Scala library;
2011-11-28 ago explicit indication of modules for independent Scala library;
2011-11-28 ago separate module for concrete Isabelle markup;
2011-09-04 ago moved XML/YXML to src/Pure/PIDE;