NEWS: value-oriented Pretty.T;

proper formal sections;

tuned signature: more options;

clarified Pretty.markup_block: use value-oriented YXML.output_markup, with final re-interpretation via print_mode in output_tree; clarified Pretty.symbolic: always use YXML.output_markup;

minor performance tuning;

unused;

prefer static YXML.output_markup_only (without print_mode): Output.status is only relevant for PIDE (with print_mode "isabelle_process");

clarified signature: more explicit type output_ops: default via print_mode;

discontinued unused global variable (see also following bf465f335e85);

tuned signature;

clarified modules (see also ea7c2ee8a47a);

clarified signature: more explicit type "ops";

more thorough Protocol_Message.clean_output, following Isabelle/Scala;

more accurate output, following 3f02bc5a5a03;

clarified signature;

clarified signature;

misc tuning and clarification;

proper signature (amending 0f820da558f9);

more accurate output: observe depth as in "prune" operation;

clarified signature, following 1f718be3608b: Pretty.str is now value-oriented;

clarified signature and modules;

tuned;

clarified Pretty.T vs. output tree (following Isabelle/Scala): Output.output_width (via print_mode) happens during formatting, instead of construction; minor performance tuning: omit block_length for Pretty.symbolic and Pretty.unformatted;

clarified signature: type ML_Pretty.pretty coincides with PolyML.pretty;

clarified signature (see also 8bef51521f21);

tuned signature;

more accurate Default_Metric;

tuned signature;