split readline into it's own module directory

This commit is contained in:
2025-05-18 14:42:00 -04:00
parent f51dc9e3b8
commit 73e7c0efc4
3 changed files with 245 additions and 185 deletions

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#[derive(Default,Debug)]
pub struct LineBuf {
pub buffer: Vec<char>,
cursor: usize
}
impl LineBuf {
pub fn new() -> Self {
Self::default()
}
pub fn count_lines(&self) -> usize {
self.buffer.iter().filter(|&&c| c == '\n').count()
}
pub fn cursor(&self) -> usize {
self.cursor
}
pub fn clear(&mut self) {
self.buffer.clear();
self.cursor = 0;
}
pub fn insert_at_cursor(&mut self, ch: char) {
self.buffer.insert(self.cursor, ch);
self.move_cursor_right();
}
pub fn backspace_at_cursor(&mut self) {
assert!(self.cursor <= self.buffer.len());
if self.buffer.is_empty() {
return
}
self.buffer.remove(self.cursor.saturating_sub(1));
self.move_cursor_left();
}
pub fn del_at_cursor(&mut self) {
assert!(self.cursor <= self.buffer.len());
if self.buffer.is_empty() || self.cursor == self.buffer.len() {
return
}
self.buffer.remove(self.cursor);
}
pub fn move_cursor_left(&mut self) {
self.cursor = self.cursor.saturating_sub(1);
}
pub fn move_cursor_start(&mut self) {
self.cursor = 0;
}
pub fn move_cursor_end(&mut self) {
self.cursor = self.buffer.len();
}
pub fn move_cursor_right(&mut self) {
if self.cursor == self.buffer.len() {
return
}
self.cursor = self.cursor.saturating_add(1);
}
pub fn del_from_cursor(&mut self) {
self.buffer.truncate(self.cursor);
}
pub fn del_word_back(&mut self) {
if self.cursor == 0 {
return
}
let end = self.cursor;
let mut start = self.cursor;
while start > 0 && self.buffer[start - 1].is_whitespace() {
start -= 1;
}
while start > 0 && !self.buffer[start - 1].is_whitespace() {
start -= 1;
}
self.buffer.drain(start..end);
self.cursor = start;
}
}
pub fn strip_ansi_codes(s: &str) -> String {
let mut out = String::with_capacity(s.len());
let mut chars = s.chars().peekable();
while let Some(c) = chars.next() {
if c == '\x1b' && chars.peek() == Some(&'[') {
// Skip over the escape sequence
chars.next(); // consume '['
while let Some(&ch) = chars.peek() {
if ch.is_ascii_lowercase() || ch.is_ascii_uppercase() {
chars.next(); // consume final letter
break;
}
chars.next(); // consume intermediate characters
}
} else {
out.push(c);
}
}
out
}

343
src/prompt/readline/mod.rs Normal file
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use std::{arch::asm, os::fd::BorrowedFd};
use line::{strip_ansi_codes, LineBuf};
use nix::{libc::STDIN_FILENO, sys::termios::{self, Termios}, unistd::read};
use term::Terminal;
use unicode_width::UnicodeWidthStr;
use crate::{libsh::{error::ShResult, sys::sh_quit}, prelude::*};
pub mod term;
pub mod line;
#[derive(Clone,Copy,Debug)]
pub enum Key {
Char(char),
Enter,
Backspace,
Delete,
Esc,
Up,
Down,
Left,
Right,
Ctrl(char),
Unknown,
}
#[derive(Clone,Debug)]
pub enum EditAction {
Return,
Exit(i32),
ClearTerm,
ClearLine,
Signal(i32),
MoveCursorStart,
MoveCursorEnd,
MoveCursorLeft, // Ctrl + B
MoveCursorRight, // Ctrl + F
DelWordBack,
DelFromCursor,
Backspace, // The Ctrl+H version
RedrawScreen,
HistNext,
HistPrev,
InsMode(InsAction),
NormMode(NormAction),
}
#[derive(Clone,Debug)]
pub enum InsAction {
InsChar(char),
Backspace, // The backspace version
Delete,
Esc,
MoveLeft, // Left Arrow
MoveRight, // Right Arrow
MoveUp,
MoveDown
}
#[derive(Clone,Debug)]
pub enum NormAction {
Count(usize),
Motion(Motion),
}
#[derive(Clone,Debug)]
pub enum Motion {
}
impl EditAction {
pub fn is_return(&self) -> bool {
matches!(self, Self::Return)
}
}
#[derive(Default,Debug)]
pub struct FernReader {
pub term: Terminal,
pub prompt: String,
pub line: LineBuf,
pub edit_mode: EditMode
}
impl FernReader {
pub fn new(prompt: String) -> Self {
Self {
term: Terminal::new(),
prompt,
line: Default::default(),
edit_mode: Default::default()
}
}
fn pack_line(&mut self) -> String {
self.line
.buffer
.iter()
.collect::<String>()
}
pub fn readline(&mut self) -> ShResult<String> {
self.display_line(/*refresh: */ false);
loop {
let cmds = self.get_cmds();
for cmd in &cmds {
if cmd.is_return() {
self.term.write_bytes(b"\r\n");
return Ok(self.pack_line())
}
}
self.process_cmds(cmds)?;
self.display_line(/* refresh: */ true);
}
}
pub fn process_cmds(&mut self, cmds: Vec<EditAction>) -> ShResult<()> {
for cmd in cmds {
match cmd {
EditAction::Exit(code) => {
self.term.write_bytes(b"\r\n");
sh_quit(code)
}
EditAction::ClearTerm => self.term.clear(),
EditAction::ClearLine => self.line.clear(),
EditAction::Signal(sig) => todo!(),
EditAction::MoveCursorStart => self.line.move_cursor_start(),
EditAction::MoveCursorEnd => self.line.move_cursor_end(),
EditAction::MoveCursorLeft => self.line.move_cursor_left(),
EditAction::MoveCursorRight => self.line.move_cursor_right(),
EditAction::DelWordBack => self.line.del_word_back(),
EditAction::DelFromCursor => self.line.del_from_cursor(),
EditAction::Backspace => self.line.backspace_at_cursor(),
EditAction::RedrawScreen => self.term.clear(),
EditAction::HistNext => todo!(),
EditAction::HistPrev => todo!(),
EditAction::InsMode(ins_action) => self.process_ins_cmd(ins_action)?,
EditAction::NormMode(norm_action) => self.process_norm_cmd(norm_action)?,
EditAction::Return => unreachable!(), // handled earlier
}
}
Ok(())
}
pub fn process_ins_cmd(&mut self, cmd: InsAction) -> ShResult<()> {
match cmd {
InsAction::InsChar(ch) => self.line.insert_at_cursor(ch),
InsAction::Backspace => self.line.backspace_at_cursor(),
InsAction::Delete => self.line.del_at_cursor(),
InsAction::Esc => todo!(),
InsAction::MoveLeft => self.line.move_cursor_left(),
InsAction::MoveRight => self.line.move_cursor_right(),
InsAction::MoveUp => todo!(),
InsAction::MoveDown => todo!(),
}
Ok(())
}
pub fn process_norm_cmd(&mut self, cmd: NormAction) -> ShResult<()> {
match cmd {
NormAction::Count(num) => todo!(),
NormAction::Motion(motion) => todo!(),
}
Ok(())
}
pub fn get_cmds(&mut self) -> Vec<EditAction> {
match self.edit_mode {
EditMode::Normal => {
let keys = self.read_keys_normal_mode();
self.process_keys_normal_mode(keys)
}
EditMode::Insert => {
let key = self.read_key().unwrap();
self.process_key_insert_mode(key)
}
}
}
pub fn read_keys_normal_mode(&mut self) -> Vec<Key> {
todo!()
}
pub fn process_keys_normal_mode(&mut self, keys: Vec<Key>) -> Vec<EditAction> {
todo!()
}
pub fn process_key_insert_mode(&mut self, key: Key) -> Vec<EditAction> {
match key {
Key::Char(ch) => {
vec![EditAction::InsMode(InsAction::InsChar(ch))]
}
Key::Enter => {
vec![EditAction::Return]
}
Key::Backspace => {
vec![EditAction::InsMode(InsAction::Backspace)]
}
Key::Delete => {
vec![EditAction::InsMode(InsAction::Delete)]
}
Key::Esc => {
vec![EditAction::InsMode(InsAction::Esc)]
}
Key::Up => {
vec![EditAction::InsMode(InsAction::MoveUp)]
}
Key::Down => {
vec![EditAction::InsMode(InsAction::MoveDown)]
}
Key::Left => {
vec![EditAction::InsMode(InsAction::MoveLeft)]
}
Key::Right => {
vec![EditAction::InsMode(InsAction::MoveRight)]
}
Key::Ctrl(ctrl) => self.process_ctrl(ctrl),
Key::Unknown => unimplemented!("Unknown key received: {key:?}")
}
}
pub fn process_ctrl(&mut self, ctrl: char) -> Vec<EditAction> {
match ctrl {
'D' => {
if self.line.buffer.is_empty() {
vec![EditAction::Exit(0)]
} else {
vec![EditAction::Return]
}
}
'C' => {
vec![EditAction::ClearLine]
}
'Z' => {
vec![EditAction::Signal(20)] // SIGTSTP
}
'A' => {
vec![EditAction::MoveCursorStart]
}
'E' => {
vec![EditAction::MoveCursorEnd]
}
'B' => {
vec![EditAction::MoveCursorLeft]
}
'F' => {
vec![EditAction::MoveCursorRight]
}
'U' => {
vec![EditAction::ClearLine]
}
'W' => {
vec![EditAction::DelWordBack]
}
'K' => {
vec![EditAction::DelFromCursor]
}
'H' => {
vec![EditAction::Backspace]
}
'L' => {
vec![EditAction::RedrawScreen]
}
'N' => {
vec![EditAction::HistNext]
}
'P' => {
vec![EditAction::HistPrev]
}
_ => unimplemented!("Unhandled control character: {ctrl}")
}
}
fn clear_line(&self) {
let prompt_lines = self.prompt.lines().count();
let buf_lines = self.line.count_lines().saturating_sub(1); // One of the buffer's lines will overlap with the prompt. probably.
let total = prompt_lines + buf_lines;
self.term.write_bytes(b"\r\n");
for _ in 0..total {
self.term.write_bytes(b"\r\x1b[2K\x1b[1A");
}
self.term.write_bytes(b"\r\x1b[2K");
}
fn display_line(&mut self, refresh: bool) {
if refresh {
self.clear_line();
}
let mut prompt_lines = self.prompt.lines().peekable();
let mut last_line_len = 0;
while let Some(line) = prompt_lines.next() {
if prompt_lines.peek().is_none() {
last_line_len = strip_ansi_codes(line).width();
self.term.write(line);
} else {
self.term.writeln(line);
}
}
let line = self.pack_line();
self.term.write(&line);
let cursor_offset = self.line.cursor() + last_line_len;
self.term.write(&format!("\r\x1b[{}C", cursor_offset));
}
fn read_key(&mut self) -> Option<Key> {
let mut buf = [0; 4];
let n = self.term.read_byte(&mut buf);
if n == 0 {
return None;
}
match buf[0] {
b'\x1b' => {
if n == 3 {
match (buf[1], buf[2]) {
(b'[', b'A') => Some(Key::Up),
(b'[', b'B') => Some(Key::Down),
(b'[', b'C') => Some(Key::Right),
(b'[', b'D') => Some(Key::Left),
_ => {
flog!(WARN, "unhandled control seq: {},{}", buf[1] as char, buf[2] as char);
Some(Key::Esc)
}
}
} else if n == 4 {
match (buf[1], buf[2], buf[3]) {
(b'[', b'3', b'~') => Some(Key::Delete),
_ => {
flog!(WARN, "unhandled control seq: {},{},{}", buf[1] as char, buf[2] as char, buf[3] as char);
Some(Key::Esc)
}
}
} else {
Some(Key::Esc)
}
}
b'\r' | b'\n' => Some(Key::Enter),
0x7f => Some(Key::Backspace),
c if (c as char).is_ascii_control() => {
let ctrl = (c ^ 0x40) as char;
Some(Key::Ctrl(ctrl))
}
c => Some(Key::Char(c as char))
}
}
}
#[derive(Default,Debug)]
pub enum EditMode {
Normal,
#[default]
Insert,
}

106
src/prompt/readline/term.rs Normal file
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use std::{arch::asm, os::fd::{BorrowedFd, RawFd}};
use nix::{libc::STDIN_FILENO, sys::termios, unistd::isatty};
#[derive(Debug)]
pub struct Terminal {
stdin: RawFd,
stdout: RawFd,
}
impl Terminal {
pub fn new() -> Self {
assert!(isatty(0).unwrap());
Self {
stdin: 0,
stdout: 1,
}
}
fn raw_mode() -> termios::Termios {
// Get the current terminal attributes
let orig_termios = unsafe { termios::tcgetattr(BorrowedFd::borrow_raw(STDIN_FILENO)).expect("Failed to get terminal attributes") };
// Make a mutable copy
let mut raw = orig_termios.clone();
// Apply raw mode flags
termios::cfmakeraw(&mut raw);
// Set the attributes immediately
unsafe { termios::tcsetattr(BorrowedFd::borrow_raw(STDIN_FILENO), termios::SetArg::TCSANOW, &raw) }
.expect("Failed to set terminal to raw mode");
// Return original attributes so they can be restored later
orig_termios
}
pub fn restore_termios(termios: termios::Termios) {
unsafe { termios::tcsetattr(BorrowedFd::borrow_raw(STDIN_FILENO), termios::SetArg::TCSANOW, &termios) }
.expect("Failed to restore terminal settings");
}
pub fn with_raw_mode<F: FnOnce() -> R,R>(func: F) -> R {
let saved = Self::raw_mode();
let result = std::panic::catch_unwind(std::panic::AssertUnwindSafe(func));
Self::restore_termios(saved);
match result {
Ok(r) => r,
Err(e) => std::panic::resume_unwind(e)
}
}
pub fn read_byte(&self, buf: &mut [u8]) -> usize {
Self::with_raw_mode(|| {
let ret: usize;
unsafe {
let buf_ptr = buf.as_mut_ptr();
let len = buf.len();
asm! (
"syscall",
in("rax") 0,
in("rdi") self.stdin,
in("rsi") buf_ptr,
in("rdx") len,
lateout("rax") ret,
out("rcx") _,
out("r11") _,
);
}
ret
})
}
pub fn write_bytes(&self, buf: &[u8]) {
Self::with_raw_mode(|| {
let _ret: usize;
unsafe {
let buf_ptr = buf.as_ptr();
let len = buf.len();
asm!(
"syscall",
in("rax") 1,
in("rdi") self.stdout,
in("rsi") buf_ptr,
in("rdx") len,
lateout("rax") _ret,
out("rcx") _,
out("r11") _,
);
}
});
}
pub fn write(&self, s: &str) {
self.write_bytes(s.as_bytes());
}
pub fn writeln(&self, s: &str) {
self.write(s);
self.write_bytes(b"\r\n");
}
pub fn clear(&self) {
self.write_bytes(b"\x1b[2J\x1b[H");
}
}
impl Default for Terminal {
fn default() -> Self {
Self::new()
}
}