Replicate bashism "process substitution" in xonsh.

.xonshrc.py

# .xonshrc
# use t() like this or in similar contexts:
#
# >>> diff -u @(t("ls -1 foo/")) @(t("ls -1 bar/"))


def t(args, *, shell=None, **kwargs):

    import builtins
    import pathlib

    from subprocess import run
    from tempfile import NamedTemporaryFile

    class bytes(builtins.bytes):

        def __new__(cls, *args, temp_file=None, **kwargs) -> __class__:

            obj = super().__new__(cls, *args, **kwargs)

            if temp_file is None and args:
                if isinstance(args[0], __class__):
                    temp_file = args[0].__temp_file
                elif isinstance(args[0], Path):
                    temp_file = args[0]._Path__temp_file
                elif isinstance(args[0]. str):
                    temp_file = args[0]._str__temp_file

            obj.__temp_file = temp_file

            return obj

    class str(builtins.str):

        def __new__(cls, *args, temp_file=None, **kwargs) -> __class__:

            obj = super().__new__(cls, *args, **kwargs)

            if temp_file is None and args:
                if isinstance(args[0], __class__):
                    temp_file = args[0].__temp_file
                elif isinstance(args[0], Path):
                    temp_file = args[0]._Path__temp_file
                elif isinstance(args[0], bytes):
                    temp_file = args[0]._bytes__temp_file

            obj.__temp_file = temp_file

            return obj

    class Path(pathlib.Path):

        __slots__ = ('__temp_file',)

        def __init__(self, *args, temp_file=None, **kwargs) -> None:

            super().__init__(*args, **kwargs)

            if temp_file is None and args:
                if isinstance(args[0], __class__):
                    temp_file = args[0].__temp_file
                elif isinstance(args[0], bytes):
                    temp_file = args[0]._bytes__temp_file
                elif isinstance(args[0], str):
                    temp_file = args[0]._str__temp_file

            self.__temp_file = temp_file

        def __new__(cls, *args, **kwargs) -> __class__:

            if cls is __class__:
                cls = WindowsPath if os.name == 'nt' else PosixPath
            return object.__new__(cls)

        def __bytes__(self) -> builtins.bytes:

            return bytes(super().__bytes__(), temp_file=self.__temp_file)

        def __str__(self) -> builtins.str:

            return str(super().__str__(), temp_file=self.__temp_file)

    class WindowsPath(Path, pathlib.WindowsPath):

        __slots__ = ()

        if os.name != 'nt':
            def __new__(cls, *args, **kwargs):
                raise NotImplementedError("no WindowsPaths on POSIX systems")

    class PosixPath(Path, pathlib.PosixPath):

        __slots__ = ()

        if os.name == 'nt':
            def __new__(cls, *args, **kwargs):
                raise NotImplementedError("no PosixPaths on Windows systems")

    if shell is None:
        shell = isinstance(args, builtins.str)

    temp_file = NamedTemporaryFile(delete=True, delete_on_close=False)

    try:
    	result = run(args, shell=shell, check=True, **kwargs, stdout=temp_file)

    finally:
        temp_file.close()

    return Path(temp_file.name, temp_file=temp_file)