Add --classes optional flag in list_files

from glob import glob

from pathlib import Path

from os.path import join, relpath

from itertools import chain

import argparse

class FileLister:

        self.folder_dir = args.dir

        self.extensions = [e if e.startswith(".") else "." + e for e in args.extensions]

        self.root = args.root

        self.files_list = list()

        self.files_list : List[str] = list()

        self.classes = args.classes

    def get_files(self) -> None:

        """Get all files directory in the input directory including the files in the subdirectories

    def list(self) -> None:

        self.get_files()

        self.files_list = [f for f in self.files_list if not self.extensions or Path(f).suffix in self.extensions]

        # If files_list is as below:

        # A/B/C.java

        # A/B/D.java

        # A/B/E.txt

        # --classes flag converts files_list in the following format:

        # A/B/C.class

        # A/B/C$*.class

        # A/B/D.class

        # A/B/D$*.class

        # Additional `$*`-suffixed line is appended after each line

        # to take multiple top level classes in a single java file into account.

        # Note that non-java files in files_list are filtered out.

        if self.classes:

            self.files_list = list(chain.from_iterable([

                (class_files := str(Path(ff).with_suffix(".class")),

                 class_files.replace(".class", "$*.class"))

                 for ff in self.files_list if ff.endswith(".java")

            ]))

        self.write()

    def write(self) -> None:

                        help="optional directory to replace the root directories of output.")

    parser.add_argument('--extensions', nargs='*', default=list(), dest='extensions',

                        help="Extensions to include in the output. If not set, all files are included")

    parser.add_argument('--classes', dest='classes', action=argparse.BooleanOptionalAction,

                        help="Optional flag. If passed, outputs a list of pattern of class files \

                                that will be produced by compiling java files in the input dir. \

                                Non-java files in the input directory will be ignored.")

    args = parser.parse_args()