lib/Tools/options

adding some example that motivates some of the current changes in the set_comprehension_pointfree simproc

#!/usr/bin/env bash
#
# Author: Makarius
#
# DESCRIPTION: print Isabelle system options


## diagnostics

PRG="$(basename "$0")"

function usage()
{
  echo
  echo "Usage: isabelle $PRG [OPTIONS] [MORE_OPTIONS ...]"
  echo
  echo "  Options are:"
  echo "    -b           include \$ISABELLE_BUILD_OPTIONS"
  echo "    -x FILE      export to FILE in YXML format"
  echo
  echo "  Print Isabelle system options, augmented by MORE_OPTIONS given as"
  echo "  arguments NAME=VAL or NAME."
  echo
  exit 1
}

function fail()
{
  echo "$1" >&2
  exit 2
}


## process command line

eval "declare -a BUILD_OPTIONS=()"
EXPORT_FILE=""

while getopts "bx:" OPT
do
  case "$OPT" in
    b)
      BUILD_OPTIONS=($ISABELLE_BUILD_OPTIONS)
      ;;
    x)
      EXPORT_FILE="$OPTARG"
      ;;
    \?)
      usage
      ;;
  esac
done

shift $(($OPTIND - 1))


## main

[ -e "$ISABELLE_HOME/Admin/build" ] && { "$ISABELLE_HOME/Admin/build" jars || exit $?; }

exec "$ISABELLE_TOOL" java isabelle.Options "$EXPORT_FILE" "${BUILD_OPTIONS[@]}" "$@"