more accurate pretty_margin for proportional fonts;

clarified signature: more uniform;

tuned: fewer warnings in IntelliJ IDEA;

tuned signature;

tuned signature;

clarified signature with subtle change of semantics: output consists of individual messages that are formatted (and separated) internally;

more accurate message boundaries;

tuned whitespace;

clarified signature: more robust type XML.Elem;

clarified signature;

clarified signature;

clarified output representation: postpone Pretty.separate;

tuned;

tuned: fewer warnings in IntelliJ IDEA;

clarified signature: more accurate types;

tuned signature: more standard names;