# Copyright 2000-2010 Michael Hudson-Doyle # Antonio Cuni # Armin Rigo # # All Rights Reserved # # # Permission to use, copy, modify, and distribute this software and # its documentation for any purpose is hereby granted without fee, # provided that the above copyright notice appear in all copies and # that both that copyright notice and this permission notice appear in # supporting documentation. # # THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO # THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY # AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, # INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER # RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF # CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN # CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. from __future__ import annotations from contextlib import contextmanager from dataclasses import dataclass, field, fields import unicodedata from _colorize import can_colorize, ANSIColors # type: ignore[import-not-found] from . import commands, console, input from .utils import ANSI_ESCAPE_SEQUENCE, wlen, str_width from .trace import trace # types Command = commands.Command if False: from .types import Callback, SimpleContextManager, KeySpec, CommandName def disp_str(buffer: str) -> tuple[str, list[int]]: """disp_str(buffer:string) -> (string, [int]) Return the string that should be the printed representation of |buffer| and a list detailing where the characters of |buffer| get used up. E.g.: >>> disp_str(chr(3)) ('^C', [1, 0]) """ b: list[int] = [] s: list[str] = [] for c in buffer: if ord(c) < 128: s.append(c) b.append(1) elif unicodedata.category(c).startswith("C"): c = r"\u%04x" % ord(c) s.append(c) b.extend([0] * (len(c) - 1)) else: s.append(c) b.append(str_width(c)) return "".join(s), b # syntax classes: SYNTAX_WHITESPACE, SYNTAX_WORD, SYNTAX_SYMBOL = range(3) def make_default_syntax_table() -> dict[str, int]: # XXX perhaps should use some unicodedata here? st: dict[str, int] = {} for c in map(chr, range(256)): st[c] = SYNTAX_SYMBOL for c in [a for a in map(chr, range(256)) if a.isalnum()]: st[c] = SYNTAX_WORD st["\n"] = st[" "] = SYNTAX_WHITESPACE return st def make_default_commands() -> dict[CommandName, type[Command]]: result: dict[CommandName, type[Command]] = {} for v in vars(commands).values(): if isinstance(v, type) and issubclass(v, Command) and v.__name__[0].islower(): result[v.__name__] = v result[v.__name__.replace("_", "-")] = v return result default_keymap: tuple[tuple[KeySpec, CommandName], ...] = tuple( [ (r"\C-a", "beginning-of-line"), (r"\C-b", "left"), (r"\C-c", "interrupt"), (r"\C-d", "delete"), (r"\C-e", "end-of-line"), (r"\C-f", "right"), (r"\C-g", "cancel"), (r"\C-h", "backspace"), (r"\C-j", "accept"), (r"\", "accept"), (r"\C-k", "kill-line"), (r"\C-l", "clear-screen"), (r"\C-m", "accept"), (r"\C-t", "transpose-characters"), (r"\C-u", "unix-line-discard"), (r"\C-w", "unix-word-rubout"), (r"\C-x\C-u", "upcase-region"), (r"\C-y", "yank"), (r"\C-z", "suspend"), (r"\M-b", "backward-word"), (r"\M-c", "capitalize-word"), (r"\M-d", "kill-word"), (r"\M-f", "forward-word"), (r"\M-l", "downcase-word"), (r"\M-t", "transpose-words"), (r"\M-u", "upcase-word"), (r"\M-y", "yank-pop"), (r"\M--", "digit-arg"), (r"\M-0", "digit-arg"), (r"\M-1", "digit-arg"), (r"\M-2", "digit-arg"), (r"\M-3", "digit-arg"), (r"\M-4", "digit-arg"), (r"\M-5", "digit-arg"), (r"\M-6", "digit-arg"), (r"\M-7", "digit-arg"), (r"\M-8", "digit-arg"), (r"\M-9", "digit-arg"), (r"\M-\n", "accept"), ("\\\\", "self-insert"), (r"\x1b[200~", "enable_bracketed_paste"), (r"\x1b[201~", "disable_bracketed_paste"), (r"\x03", "ctrl-c"), ] + [(c, "self-insert") for c in map(chr, range(32, 127)) if c != "\\"] + [(c, "self-insert") for c in map(chr, range(128, 256)) if c.isalpha()] + [ (r"\", "up"), (r"\", "down"), (r"\", "left"), (r"\C-\", "backward-word"), (r"\", "right"), (r"\C-\", "forward-word"), (r"\", "delete"), (r"\", "backspace"), (r"\M-\", "backward-kill-word"), (r"\", "end-of-line"), # was 'end' (r"\", "beginning-of-line"), # was 'home' (r"\", "help"), (r"\", "show-history"), (r"\", "paste-mode"), (r"\EOF", "end"), # the entries in the terminfo database for xterms (r"\EOH", "home"), # seem to be wrong. this is a less than ideal # workaround ] ) @dataclass(slots=True) class Reader: """The Reader class implements the bare bones of a command reader, handling such details as editing and cursor motion. What it does not support are such things as completion or history support - these are implemented elsewhere. Instance variables of note include: * buffer: A *list* (*not* a string at the moment :-) containing all the characters that have been entered. * console: Hopefully encapsulates the OS dependent stuff. * pos: A 0-based index into 'buffer' for where the insertion point is. * screeninfo: Ahem. This list contains some info needed to move the insertion point around reasonably efficiently. * cxy, lxy: the position of the insertion point in screen ... * syntax_table: Dictionary mapping characters to 'syntax class'; read the emacs docs to see what this means :-) * commands: Dictionary mapping command names to command classes. * arg: The emacs-style prefix argument. It will be None if no such argument has been provided. * dirty: True if we need to refresh the display. * kill_ring: The emacs-style kill-ring; manipulated with yank & yank-pop * ps1, ps2, ps3, ps4: prompts. ps1 is the prompt for a one-line input; for a multiline input it looks like: ps2> first line of input goes here ps3> second and further ps3> lines get ps3 ... ps4> and the last one gets ps4 As with the usual top-level, you can set these to instances if you like; str() will be called on them (once) at the beginning of each command. Don't put really long or newline containing strings here, please! This is just the default policy; you can change it freely by overriding get_prompt() (and indeed some standard subclasses do). * finished: handle1 will set this to a true value if a command signals that we're done. """ console: console.Console ## state buffer: list[str] = field(default_factory=list) pos: int = 0 ps1: str = "->> " ps2: str = "/>> " ps3: str = "|.. " ps4: str = R"\__ " kill_ring: list[list[str]] = field(default_factory=list) msg: str = "" arg: int | None = None dirty: bool = False finished: bool = False paste_mode: bool = False in_bracketed_paste: bool = False commands: dict[str, type[Command]] = field(default_factory=make_default_commands) last_command: type[Command] | None = None syntax_table: dict[str, int] = field(default_factory=make_default_syntax_table) keymap: tuple[tuple[str, str], ...] = () input_trans: input.KeymapTranslator = field(init=False) input_trans_stack: list[input.KeymapTranslator] = field(default_factory=list) screen: list[str] = field(default_factory=list) screeninfo: list[tuple[int, list[int]]] = field(init=False) cxy: tuple[int, int] = field(init=False) lxy: tuple[int, int] = field(init=False) scheduled_commands: list[str] = field(default_factory=list) can_colorize: bool = False ## cached metadata to speed up screen refreshes @dataclass class RefreshCache: in_bracketed_paste: bool = False screen: list[str] = field(default_factory=list) screeninfo: list[tuple[int, list[int]]] = field(init=False) line_end_offsets: list[int] = field(default_factory=list) pos: int = field(init=False) cxy: tuple[int, int] = field(init=False) dimensions: tuple[int, int] = field(init=False) invalidated: bool = False def update_cache(self, reader: Reader, screen: list[str], screeninfo: list[tuple[int, list[int]]], ) -> None: self.in_bracketed_paste = reader.in_bracketed_paste self.screen = screen.copy() self.screeninfo = screeninfo.copy() self.pos = reader.pos self.cxy = reader.cxy self.dimensions = reader.console.width, reader.console.height self.invalidated = False def valid(self, reader: Reader) -> bool: if self.invalidated: return False dimensions = reader.console.width, reader.console.height dimensions_changed = dimensions != self.dimensions paste_changed = reader.in_bracketed_paste != self.in_bracketed_paste return not (dimensions_changed or paste_changed) def get_cached_location(self, reader: Reader) -> tuple[int, int]: if self.invalidated: raise ValueError("Cache is invalidated") offset = 0 earliest_common_pos = min(reader.pos, self.pos) num_common_lines = len(self.line_end_offsets) while num_common_lines > 0: offset = self.line_end_offsets[num_common_lines - 1] if earliest_common_pos > offset: break num_common_lines -= 1 else: offset = 0 return offset, num_common_lines last_refresh_cache: RefreshCache = field(default_factory=RefreshCache) def __post_init__(self) -> None: # Enable the use of `insert` without a `prepare` call - necessary to # facilitate the tab completion hack implemented for # . self.keymap = self.collect_keymap() self.input_trans = input.KeymapTranslator( self.keymap, invalid_cls="invalid-key", character_cls="self-insert" ) self.screeninfo = [(0, [])] self.cxy = self.pos2xy() self.lxy = (self.pos, 0) self.can_colorize = can_colorize() self.last_refresh_cache.screeninfo = self.screeninfo self.last_refresh_cache.pos = self.pos self.last_refresh_cache.cxy = self.cxy self.last_refresh_cache.dimensions = (0, 0) def collect_keymap(self) -> tuple[tuple[KeySpec, CommandName], ...]: return default_keymap def calc_screen(self) -> list[str]: """Translate changes in self.buffer into changes in self.console.screen.""" # Since the last call to calc_screen: # screen and screeninfo may differ due to a completion menu being shown # pos and cxy may differ due to edits, cursor movements, or completion menus # Lines that are above both the old and new cursor position can't have changed, # unless the terminal has been resized (which might cause reflowing) or we've # entered or left paste mode (which changes prompts, causing reflowing). num_common_lines = 0 offset = 0 if self.last_refresh_cache.valid(self): offset, num_common_lines = self.last_refresh_cache.get_cached_location(self) screen = self.last_refresh_cache.screen del screen[num_common_lines:] screeninfo = self.last_refresh_cache.screeninfo del screeninfo[num_common_lines:] last_refresh_line_end_offsets = self.last_refresh_cache.line_end_offsets del last_refresh_line_end_offsets[num_common_lines:] pos = self.pos pos -= offset lines = "".join(self.buffer[offset:]).split("\n") cursor_found = False lines_beyond_cursor = 0 for ln, line in enumerate(lines, num_common_lines): ll = len(line) if 0 <= pos <= ll: self.lxy = pos, ln cursor_found = True elif cursor_found: lines_beyond_cursor += 1 if lines_beyond_cursor > self.console.height: # No need to keep formatting lines. # The console can't show them. break prompt = self.get_prompt(ln, ll >= pos >= 0) while "\n" in prompt: pre_prompt, _, prompt = prompt.partition("\n") last_refresh_line_end_offsets.append(offset) screen.append(pre_prompt) screeninfo.append((0, [])) pos -= ll + 1 prompt, lp = self.process_prompt(prompt) l, l2 = disp_str(line) wrapcount = (wlen(l) + lp) // self.console.width if wrapcount == 0: offset += ll + 1 # Takes all of the line plus the newline last_refresh_line_end_offsets.append(offset) screen.append(prompt + l) screeninfo.append((lp, l2)) else: i = 0 while l: prelen = lp if i == 0 else 0 index_to_wrap_before = 0 column = 0 for character_width in l2: if column + character_width >= self.console.width - prelen: break index_to_wrap_before += 1 column += character_width pre = prompt if i == 0 else "" if len(l) > index_to_wrap_before: offset += index_to_wrap_before post = "\\" after = [1] else: offset += index_to_wrap_before + 1 # Takes the newline post = "" after = [] last_refresh_line_end_offsets.append(offset) screen.append(pre + l[:index_to_wrap_before] + post) screeninfo.append((prelen, l2[:index_to_wrap_before] + after)) l = l[index_to_wrap_before:] l2 = l2[index_to_wrap_before:] i += 1 self.screeninfo = screeninfo self.cxy = self.pos2xy() if self.msg: for mline in self.msg.split("\n"): screen.append(mline) screeninfo.append((0, [])) self.last_refresh_cache.update_cache(self, screen, screeninfo) return screen @staticmethod def process_prompt(prompt: str) -> tuple[str, int]: """Process the prompt. This means calculate the length of the prompt. The character \x01 and \x02 are used to bracket ANSI control sequences and need to be excluded from the length calculation. So also a copy of the prompt is returned with these control characters removed.""" # The logic below also ignores the length of common escape # sequences if they were not explicitly within \x01...\x02. # They are CSI (or ANSI) sequences ( ESC [ ... LETTER ) # wlen from utils already excludes ANSI_ESCAPE_SEQUENCE chars, # which breaks the logic below so we redefine it here. def wlen(s: str) -> int: return sum(str_width(i) for i in s) out_prompt = "" l = wlen(prompt) pos = 0 while True: s = prompt.find("\x01", pos) if s == -1: break e = prompt.find("\x02", s) if e == -1: break # Found start and end brackets, subtract from string length l = l - (e - s + 1) keep = prompt[pos:s] l -= sum(map(wlen, ANSI_ESCAPE_SEQUENCE.findall(keep))) out_prompt += keep + prompt[s + 1 : e] pos = e + 1 keep = prompt[pos:] l -= sum(map(wlen, ANSI_ESCAPE_SEQUENCE.findall(keep))) out_prompt += keep return out_prompt, l def bow(self, p: int | None = None) -> int: """Return the 0-based index of the word break preceding p most immediately. p defaults to self.pos; word boundaries are determined using self.syntax_table.""" if p is None: p = self.pos st = self.syntax_table b = self.buffer p -= 1 while p >= 0 and st.get(b[p], SYNTAX_WORD) != SYNTAX_WORD: p -= 1 while p >= 0 and st.get(b[p], SYNTAX_WORD) == SYNTAX_WORD: p -= 1 return p + 1 def eow(self, p: int | None = None) -> int: """Return the 0-based index of the word break following p most immediately. p defaults to self.pos; word boundaries are determined using self.syntax_table.""" if p is None: p = self.pos st = self.syntax_table b = self.buffer while p < len(b) and st.get(b[p], SYNTAX_WORD) != SYNTAX_WORD: p += 1 while p < len(b) and st.get(b[p], SYNTAX_WORD) == SYNTAX_WORD: p += 1 return p def bol(self, p: int | None = None) -> int: """Return the 0-based index of the line break preceding p most immediately. p defaults to self.pos.""" if p is None: p = self.pos b = self.buffer p -= 1 while p >= 0 and b[p] != "\n": p -= 1 return p + 1 def eol(self, p: int | None = None) -> int: """Return the 0-based index of the line break following p most immediately. p defaults to self.pos.""" if p is None: p = self.pos b = self.buffer while p < len(b) and b[p] != "\n": p += 1 return p def max_column(self, y: int) -> int: """Return the last x-offset for line y""" return self.screeninfo[y][0] + sum(self.screeninfo[y][1]) def max_row(self) -> int: return len(self.screeninfo) - 1 def get_arg(self, default: int = 1) -> int: """Return any prefix argument that the user has supplied, returning 'default' if there is None. Defaults to 1. """ if self.arg is None: return default return self.arg def get_prompt(self, lineno: int, cursor_on_line: bool) -> str: """Return what should be in the left-hand margin for line 'lineno'.""" if self.arg is not None and cursor_on_line: prompt = f"(arg: {self.arg}) " elif self.paste_mode and not self.in_bracketed_paste: prompt = "(paste) " elif "\n" in self.buffer: if lineno == 0: prompt = self.ps2 elif self.ps4 and lineno == self.buffer.count("\n"): prompt = self.ps4 else: prompt = self.ps3 else: prompt = self.ps1 if self.can_colorize: prompt = f"{ANSIColors.BOLD_MAGENTA}{prompt}{ANSIColors.RESET}" return prompt def push_input_trans(self, itrans: input.KeymapTranslator) -> None: self.input_trans_stack.append(self.input_trans) self.input_trans = itrans def pop_input_trans(self) -> None: self.input_trans = self.input_trans_stack.pop() def setpos_from_xy(self, x: int, y: int) -> None: """Set pos according to coordinates x, y""" pos = 0 i = 0 while i < y: prompt_len, character_widths = self.screeninfo[i] offset = len(character_widths) - character_widths.count(0) in_wrapped_line = prompt_len + sum(character_widths) >= self.console.width if in_wrapped_line: pos += offset - 1 # -1 cause backslash is not in buffer else: pos += offset + 1 # +1 cause newline is in buffer i += 1 j = 0 cur_x = self.screeninfo[i][0] while cur_x < x: if self.screeninfo[i][1][j] == 0: continue cur_x += self.screeninfo[i][1][j] j += 1 pos += 1 self.pos = pos def pos2xy(self) -> tuple[int, int]: """Return the x, y coordinates of position 'pos'.""" # this *is* incomprehensible, yes. y = 0 pos = self.pos assert 0 <= pos <= len(self.buffer) if pos == len(self.buffer): y = len(self.screeninfo) - 1 p, l2 = self.screeninfo[y] return p + sum(l2) + l2.count(0), y for p, l2 in self.screeninfo: l = len(l2) - l2.count(0) in_wrapped_line = p + sum(l2) >= self.console.width offset = l - 1 if in_wrapped_line else l # need to remove backslash if offset >= pos: break if p + sum(l2) >= self.console.width: pos -= l - 1 # -1 cause backslash is not in buffer else: pos -= l + 1 # +1 cause newline is in buffer y += 1 return p + sum(l2[:pos]), y def insert(self, text: str | list[str]) -> None: """Insert 'text' at the insertion point.""" self.buffer[self.pos : self.pos] = list(text) self.pos += len(text) self.dirty = True def update_cursor(self) -> None: """Move the cursor to reflect changes in self.pos""" self.cxy = self.pos2xy() self.console.move_cursor(*self.cxy) def after_command(self, cmd: Command) -> None: """This function is called to allow post command cleanup.""" if getattr(cmd, "kills_digit_arg", True): if self.arg is not None: self.dirty = True self.arg = None def prepare(self) -> None: """Get ready to run. Call restore when finished. You must not write to the console in between the calls to prepare and restore.""" try: self.console.prepare() self.arg = None self.finished = False del self.buffer[:] self.pos = 0 self.dirty = True self.last_command = None self.calc_screen() except BaseException: self.restore() raise while self.scheduled_commands: cmd = self.scheduled_commands.pop() self.do_cmd((cmd, [])) def last_command_is(self, cls: type) -> bool: if not self.last_command: return False return issubclass(cls, self.last_command) def restore(self) -> None: """Clean up after a run.""" self.console.restore() @contextmanager def suspend(self) -> SimpleContextManager: """A context manager to delegate to another reader.""" prev_state = {f.name: getattr(self, f.name) for f in fields(self)} try: self.restore() yield finally: for arg in ("msg", "ps1", "ps2", "ps3", "ps4", "paste_mode"): setattr(self, arg, prev_state[arg]) self.prepare() def finish(self) -> None: """Called when a command signals that we're finished.""" pass def error(self, msg: str = "none") -> None: self.msg = "! " + msg + " " self.dirty = True self.console.beep() def update_screen(self) -> None: if self.dirty: self.refresh() def refresh(self) -> None: """Recalculate and refresh the screen.""" if self.in_bracketed_paste and self.buffer and not self.buffer[-1] == "\n": return # this call sets up self.cxy, so call it first. self.screen = self.calc_screen() self.console.refresh(self.screen, self.cxy) self.dirty = False def do_cmd(self, cmd: tuple[str, list[str]]) -> None: """`cmd` is a tuple of "event_name" and "event", which in the current implementation is always just the "buffer" which happens to be a list of single-character strings.""" trace("received command {cmd}", cmd=cmd) if isinstance(cmd[0], str): command_type = self.commands.get(cmd[0], commands.invalid_command) elif isinstance(cmd[0], type): command_type = cmd[0] else: return # nothing to do command = command_type(self, *cmd) # type: ignore[arg-type] command.do() self.after_command(command) if self.dirty: self.refresh() else: self.update_cursor() if not isinstance(cmd, commands.digit_arg): self.last_command = command_type self.finished = bool(command.finish) if self.finished: self.console.finish() self.finish() def handle1(self, block: bool = True) -> bool: """Handle a single event. Wait as long as it takes if block is true (the default), otherwise return False if no event is pending.""" if self.msg: self.msg = "" self.dirty = True while True: input_hook = self.console.input_hook if input_hook: input_hook() # We use the same timeout as in readline.c: 100ms while not self.console.wait(100): input_hook() event = self.console.get_event(block=False) else: event = self.console.get_event(block) if not event: # can only happen if we're not blocking return False translate = True if event.evt == "key": self.input_trans.push(event) elif event.evt == "scroll": self.refresh() elif event.evt == "resize": self.refresh() else: translate = False if translate: cmd = self.input_trans.get() else: cmd = [event.evt, event.data] if cmd is None: if block: continue else: return False self.do_cmd(cmd) return True def push_char(self, char: int | bytes) -> None: self.console.push_char(char) self.handle1(block=False) def readline(self, startup_hook: Callback | None = None) -> str: """Read a line. The implementation of this method also shows how to drive Reader if you want more control over the event loop.""" self.prepare() try: if startup_hook is not None: startup_hook() self.refresh() while not self.finished: self.handle1() return self.get_unicode() finally: self.restore() def bind(self, spec: KeySpec, command: CommandName) -> None: self.keymap = self.keymap + ((spec, command),) self.input_trans = input.KeymapTranslator( self.keymap, invalid_cls="invalid-key", character_cls="self-insert" ) def get_unicode(self) -> str: """Return the current buffer as a unicode string.""" return "".join(self.buffer)