How to use the bpython.curtsiesfrontend.parse.func_for_letter function in bpython

def matches_lines(rows, columns, matches, current, config, match_format):
    highlight_color = func_for_letter(config.color_scheme["operator"].lower())

    if not matches:
        return []
    color = func_for_letter(config.color_scheme["main"])
    max_match_width = max(len(m) for m in matches)
    words_wide = max(1, (columns - 1) // (max_match_width + 1))
    matches = [match_format(m) for m in matches]
    if current:
        current = match_format(current)

    matches = paginate(rows, matches, current, words_wide)

    result = [
        fmtstr(" ").join(
            color(m.ljust(max_match_width))
            if m != current
            else highlight_color(m.ljust(max_match_width))
            for m in matches[i : i + words_wide]
        )
        for i in range(0, len(matches), words_wide)

def matches_lines(rows, columns, matches, current, config, format):
    highlight_color = func_for_letter(config.color_scheme['operator'].lower())

    if not matches:
        return []
    color = func_for_letter(config.color_scheme['main'])
    max_match_width = max(len(m) for m in matches)
    words_wide = max(1, (columns - 1) // (max_match_width + 1))
    matches = [format(m) for m in matches]
    if current:
        current = format(current)

    matches = paginate(rows, matches, current, words_wide)

    matches_lines = [fmtstr(' ').join(color(m.ljust(max_match_width))
                                      if m != current
                                      else highlight_color(
                                          m.ljust(max_match_width))
                                      for m in matches[i:i + words_wide])
                     for i in range(0, len(matches), words_wide)]

    logger.debug('match: %r' % current)

def formatted_docstring(docstring, columns, config):
    if isinstance(docstring, bytes):
        docstring = docstring.decode('utf8')
    elif isinstance(docstring, str if py3 else unicode):
        pass
    else:
        # TODO: fail properly here and catch possible exceptions in callers.
        return []
    color = func_for_letter(config.color_scheme['comment'])
    return sum(([color(x) for x in (display_linize(line, columns) if line else
                                    fmtstr(''))]
                for line in docstring.split('\n')), [])

def paint_statusbar(rows, columns, msg, config):
    func = func_for_letter(config.color_scheme["main"])
    return fsarray([func(msg.ljust(columns))[:columns]])

def formatted_argspec(funcprops, arg_pos, columns, config):
    # Pretty directly taken from bpython.cli
    func = funcprops.func
    args = funcprops.argspec.args
    kwargs = funcprops.argspec.defaults
    _args = funcprops.argspec.varargs
    _kwargs = funcprops.argspec.varkwargs
    is_bound_method = funcprops.is_bound_method
    if py3:
        kwonly = funcprops.argspec.kwonly
        kwonly_defaults = funcprops.argspec.kwonly_defaults or dict()

    arg_color = func_for_letter(config.color_scheme['name'])
    func_color = func_for_letter(config.color_scheme['name'].swapcase())
    punctuation_color = func_for_letter(config.color_scheme['punctuation'])
    token_color = func_for_letter(config.color_scheme['token'])
    bolds = {token_color: lambda x: bold(token_color(x)),
             arg_color: lambda x: bold(arg_color(x))}

    s = func_color(func) + arg_color(': (')

    if is_bound_method and isinstance(arg_pos, int):
        # TODO what values could this have?
        arg_pos += 1

    for i, arg in enumerate(args):
        kw = None
        if kwargs and i >= len(args) - len(kwargs):
            kw = str(kwargs[i - (len(args) - len(kwargs))])

def formatted_argspec(funcprops, arg_pos, columns, config):
    # Pretty directly taken from bpython.cli
    func = funcprops.func
    args = funcprops.argspec.args
    kwargs = funcprops.argspec.defaults
    _args = funcprops.argspec.varargs
    _kwargs = funcprops.argspec.varkwargs
    is_bound_method = funcprops.is_bound_method
    if py3:
        kwonly = funcprops.argspec.kwonly
        kwonly_defaults = funcprops.argspec.kwonly_defaults or dict()

    arg_color = func_for_letter(config.color_scheme["name"])
    func_color = func_for_letter(config.color_scheme["name"].swapcase())
    punctuation_color = func_for_letter(config.color_scheme["punctuation"])
    token_color = func_for_letter(config.color_scheme["token"])
    bolds = {
        token_color: lambda x: bold(token_color(x)),
        arg_color: lambda x: bold(arg_color(x)),
    }

    s = func_color(func) + arg_color(": (")

    if is_bound_method and isinstance(arg_pos, int):
        # TODO what values could this have?
        arg_pos += 1

    for i, arg in enumerate(args):
        kw = None
        if kwargs and i >= len(args) - len(kwargs):

def formatted_argspec(funcprops, arg_pos, columns, config):
    # Pretty directly taken from bpython.cli
    func = funcprops.func
    args = funcprops.argspec.args
    kwargs = funcprops.argspec.defaults
    _args = funcprops.argspec.varargs
    _kwargs = funcprops.argspec.varkwargs
    is_bound_method = funcprops.is_bound_method
    if py3:
        kwonly = funcprops.argspec.kwonly
        kwonly_defaults = funcprops.argspec.kwonly_defaults or dict()

    arg_color = func_for_letter(config.color_scheme["name"])
    func_color = func_for_letter(config.color_scheme["name"].swapcase())
    punctuation_color = func_for_letter(config.color_scheme["punctuation"])
    token_color = func_for_letter(config.color_scheme["token"])
    bolds = {
        token_color: lambda x: bold(token_color(x)),
        arg_color: lambda x: bold(arg_color(x)),
    }

    s = func_color(func) + arg_color(": (")

    if is_bound_method and isinstance(arg_pos, int):
        # TODO what values could this have?
        arg_pos += 1

    for i, arg in enumerate(args):
        kw = None
        if kwargs and i >= len(args) - len(kwargs):
            kw = str(kwargs[i - (len(args) - len(kwargs))])
        color = token_color if arg_pos in (i, arg) else arg_color

from_doc = (formatted_docstring(docstring, width, config)
                if docstring else [])
    from_matches = (matches_lines(max(1, rows - len(from_argspec) - 2),
                                  width, matches, match, config, format)
                    if matches else [])

    lines = from_argspec + from_matches + from_doc

    def add_border(line):
        """Add colored borders left and right to a line."""
        new_line = border_color(config.left_border + ' ')
        new_line += line.ljust(width)[:width]
        new_line += border_color(' ' + config.right_border)
        return new_line

    border_color = func_for_letter(config.color_scheme['main'])

    top_line = border_color(config.left_top_corner +
                            config.top_border * (width + 2) +
                            config.right_top_corner)
    bottom_line = border_color(config.left_bottom_corner +
                               config.bottom_border * (width + 2) +
                               config.right_bottom_corner)

    output_lines = list(itertools.chain((top_line, ), map(add_border, lines),
                                        (bottom_line, )))
    r = fsarray(output_lines[:min(rows - 1,
                                  len(output_lines) - 1)] + output_lines[-1:])
    return r

def display_line_with_prompt(self):
        """colored line with prompt"""
        prompt = func_for_letter(self.config.color_scheme["prompt"])
        more = func_for_letter(self.config.color_scheme["prompt_more"])
        if self.incr_search_mode == "reverse_incremental_search":
            return (
                prompt(
                    "(reverse-i-search)`{}': ".format(self.incr_search_target)
                )
                + self.current_line_formatted
            )
        elif self.incr_search_mode == "incremental_search":
            return (
                prompt("(i-search)`%s': ".format(self.incr_search_target))
                + self.current_line_formatted
            )
        return (
            prompt(self.ps1) if self.done else more(self.ps2)
        ) + self.current_line_formatted