implemented autosuggestions for the line editor

src/expand.rs

@@ -13,6 +13,16 @@ use crate::parse::execute::exec_input;
 use crate::parse::lex::{is_field_sep, is_hard_sep, LexFlags, LexStream, Tk, TkFlags, TkRule};
 use crate::libsh::error::{ShErr, ShErrKind, ShResult};
 
+const PARAMETERS: [char;7] = [
+	'@',
+	'*',
+	'#',
+	'$',
+	'?',
+	'!',
+	'0'
+];
+
 /// Variable substitution marker
 pub const VAR_SUB: char = '\u{fdd0}';
 /// Double quote '"' marker
@@ -170,6 +180,13 @@ pub fn expand_var(chars: &mut Peekable<Chars<'_>>) -> ShResult<String> {
 				chars.next(); // safe to consume
 				var_name.push(ch);
 			}
+			ch if var_name.is_empty() && PARAMETERS.contains(&ch) => {
+				chars.next();
+				let parameter = format!("{ch}");
+				let val = read_vars(|v| v.get_var(&parameter));
+				flog!(DEBUG, val);
+				return Ok(val)
+			}
 			ch if is_hard_sep(ch) || !(ch.is_alphanumeric() || ch == '_' || ch == '-') => {
 				let val = read_vars(|v| v.get_var(&var_name));
 				flog!(INFO,var_name);
@@ -627,7 +644,13 @@ pub fn unescape_str(raw: &str) -> String {
 					}
 				}
 			}
-			'$' => result.push(VAR_SUB),
+			'$' => {
+				result.push(VAR_SUB);
+				if chars.peek() == Some(&'$') {
+					chars.next();
+					result.push('$');
+				}
+			}
 			_ => result.push(ch)
 		}
 		first_char = false;

src/parse/execute.rs

@@ -198,13 +198,14 @@ impl Dispatcher {
 		self.io_stack.append_to_frame(func.redirs);
 
 		let func_name = argv.remove(0).span.as_str().to_string();
+		let argv = prepare_argv(argv)?;
 		if let Some(func) = read_logic(|l| l.get_func(&func_name)) {
 			let snapshot = get_snapshots();
 			// Set up the inner scope
 			write_vars(|v| {
 				**v = VarTab::new();
 				v.clear_args();
-				for arg in argv {
+				for (arg,_) in argv {
 					v.bpush_arg(arg.to_string());
 				}
 			});

src/parse/mod.rs

@@ -696,6 +696,8 @@ impl ParseStream {
 			return Ok(None)
 		}
 		node_tks.push(self.next_tk().unwrap());
+
+		self.catch_separator(&mut node_tks);
 	
 
 		loop {
@@ -707,6 +709,9 @@ impl ParseStream {
 				node_tks.extend(node.tokens.clone());
 				body.push(node);
 			}
+			dbg!(&self.tokens);
+			panic!("{body:#?}");
+			self.catch_separator(&mut node_tks);
 			if !self.next_tk_is_some() {
 				self.panic_mode(&mut node_tks);
 				return Err(parse_err_full(

src/prompt/readline/history.rs

@@ -1,11 +1,30 @@
 use std::{env, fmt::{Write,Display}, fs::{self, OpenOptions}, io::Write as IoWrite, path::{Path, PathBuf}, str::FromStr, time::{Duration, SystemTime, UNIX_EPOCH}};
 
-use crate::libsh::error::{ShErr, ShErrKind, ShResult};
+use crate::libsh::{error::{ShErr, ShErrKind, ShResult}, term::{Style, Styled}};
 use crate::prelude::*;
 
 use super::vicmd::Direction; // surprisingly useful
 
-#[derive(Debug)]
+#[derive(Default,Clone,Copy,Debug)]
+pub enum SearchKind {
+	Fuzzy,
+	#[default]
+	Prefix
+}
+
+#[derive(Default,Clone,Debug)]
+pub struct SearchConstraint {
+	kind: SearchKind,
+	term: String,
+}
+
+impl SearchConstraint {
+	pub fn new(kind: SearchKind, term: String) -> Self {
+		Self { kind, term }
+	}
+}
+
+#[derive(Debug,Clone)]
 pub struct HistEntry {
 	id: u32,
 	timestamp: SystemTime,
@@ -42,6 +61,9 @@ impl HistEntry {
 		}
 		escaped
 	}
+	pub fn is_new(&self) -> bool {
+		self.new
+	}
 }
 
 impl FromStr for HistEntry {
@@ -145,6 +167,7 @@ fn read_hist_file(path: &Path) -> ShResult<Vec<HistEntry>> {
 pub struct History {
 	path: PathBuf,
 	entries: Vec<HistEntry>,
+	search_mask: Vec<HistEntry>,
 	cursor: usize,
 	search_direction: Direction,
 	ignore_dups: bool,
@@ -157,11 +180,19 @@ impl History {
 			let home = env::var("HOME").unwrap();
 			format!("{home}/.fern_history")
 		}));
-		let entries = read_hist_file(&path)?;
+		let mut entries = read_hist_file(&path)?;
-		let cursor = entries.len();
+		{
+			let id = entries.last().map(|ent| ent.id + 1).unwrap_or(0);
+			let timestamp = SystemTime::now();
+			let command = "".into();
+			entries.push(HistEntry { id, timestamp, command, new: true })
+		}
+		let search_mask = entries.clone();
+		let cursor = entries.len() - 1;
 		let mut new = Self {
 			path,
 			entries,
+			search_mask,
 			cursor,
 			search_direction: Direction::Backward,
 			ignore_dups: true,
@@ -176,19 +207,22 @@ impl History {
 	}
 
 	pub fn push_empty_entry(&mut self) {
-		let id = self.get_new_id();
+	}
-		let timestamp = SystemTime::now();
+
-		let command = "".into();
+	pub fn cursor_entry(&self) -> Option<&HistEntry> {
-		self.entries.push(HistEntry { id, timestamp, command, new: true })
+		self.search_mask.get(self.cursor)
 	}
 
 	pub fn update_pending_cmd(&mut self, command: &str) {
-		flog!(DEBUG, "updating command");
 		let Some(ent) = self.last_mut() else {
 			return
 		};
+		let cmd = command.to_string();
+		let constraint = SearchConstraint { kind: SearchKind::Prefix, term: cmd.clone() };
 
-		ent.command = command.to_string()
+
+		ent.command = cmd;
+		self.constrain_entries(constraint);
 	}
 
 	pub fn last_mut(&mut self) -> Option<&mut HistEntry> {
@@ -210,11 +244,46 @@ impl History {
 		self.max_size = size
 	}
 
+	pub fn constrain_entries(&mut self, constraint: SearchConstraint) {
+		let SearchConstraint { kind, term } = constraint;
+		match kind {
+			SearchKind::Prefix => {
+				if term.is_empty() {
+					self.search_mask = self.entries.clone();
+				} else {
+					let filtered = self.entries
+						.clone()
+						.into_iter()
+						.filter(|ent| ent.command().starts_with(&term));
+
+					self.search_mask = filtered.collect();
+				}
+				self.cursor = self.search_mask.len().saturating_sub(1);
+			}
+			SearchKind::Fuzzy => todo!(),
+		}
+	}
+
+	pub fn hint_entry(&self) -> Option<&HistEntry> {
+		let second_to_last = self.search_mask.len().checked_sub(2)?;
+		self.search_mask.get(second_to_last)
+	}
+
+	pub fn get_hint(&self) -> Option<String> {
+		if self.cursor_entry().is_some_and(|ent| ent.is_new() && !ent.command().is_empty()) {
+			let entry = self.hint_entry()?;
+			let prefix = self.cursor_entry()?.command();
+			Some(entry.command().strip_prefix(prefix)?.to_string())
+		} else {
+			None
+		}
+	}
+
 	pub fn scroll(&mut self, offset: isize) -> Option<&HistEntry> {
 		let new_idx = self.cursor
 			.saturating_add_signed(offset)
-			.clamp(0, self.entries.len());
+			.clamp(0, self.search_mask.len().saturating_sub(1));
-		let ent = self.entries.get(new_idx)?;
+		let ent = self.search_mask.get(new_idx)?;
 
 		self.cursor = new_idx;
 
@@ -244,7 +313,7 @@ impl History {
 			.append(true)
 			.open(&self.path)?;
 
-		let entries = self.entries.iter_mut().filter(|ent| ent.new);
+		let entries = self.entries.iter_mut().filter(|ent| ent.new && !ent.command.is_empty());
 		let mut data = String::new();
 		for ent in entries {
 			ent.new = false;

src/prompt/readline/linebuf.rs

@@ -3,7 +3,7 @@ use std::{cmp::Ordering, fmt::Display, ops::{Range, RangeBounds}};
 use unicode_segmentation::UnicodeSegmentation;
 use unicode_width::UnicodeWidthStr;
 
-use crate::libsh::{error::ShResult, sys::sh_quit};
+use crate::libsh::{error::ShResult, sys::sh_quit, term::{Style, Styled}};
 use crate::prelude::*;
 
 use super::vicmd::{Anchor, Bound, Dest, Direction, Motion, RegisterName, TextObj, To, Verb, ViCmd, Word};
@@ -147,6 +147,7 @@ impl Edit {
 #[derive(Default,Debug)]
 pub struct LineBuf {
 	buffer: String,
+	hint: Option<String>,
 	cursor: usize,
 	clamp_cursor: bool,
 	first_line_offset: usize,
@@ -166,6 +167,12 @@ impl LineBuf {
 		self.buffer = initial.to_string();
 		self
 	}
+	pub fn has_hint(&self) -> bool {
+		self.hint.is_some()
+	}
+	pub fn set_hint(&mut self, hint: Option<String>) {
+		self.hint = hint
+	}
 	pub fn set_first_line_offset(&mut self, offset: usize) {
 		self.first_line_offset = offset
 	}
@@ -189,6 +196,13 @@ impl LineBuf {
 	pub fn byte_len(&self) -> usize {
 		self.buffer.len()
 	}
+	pub fn at_end_of_buffer(&self) -> bool {
+		if self.clamp_cursor {
+			self.cursor == self.byte_len().saturating_sub(1)
+		} else {
+			self.cursor == self.byte_len()
+		}
+	}
 	pub fn undos(&self) -> usize {
 		self.undo_stack.len()
 	}
@@ -480,7 +494,11 @@ impl LineBuf {
 		self.move_to(0)
 	}
 	pub fn move_buf_end(&mut self) -> bool {
-		self.move_to(self.byte_len())
+		if self.clamp_cursor {
+			self.move_to(self.byte_len().saturating_sub(1))
+		} else {
+			self.move_to(self.byte_len())
+		}
 	}
 	pub fn move_home(&mut self) -> bool {
 		let start = self.start_of_line();
@@ -490,6 +508,63 @@ impl LineBuf {
 		let end = self.end_of_line();
 		self.move_to(end)
 	}
+	pub fn accept_hint(&mut self) {
+		if let Some(hint) = self.hint.take() {
+			flog!(DEBUG, "accepting hint");
+			let old_buf = self.buffer.clone();
+			self.buffer.push_str(&hint);
+			let new_buf = self.buffer.clone();
+			self.handle_edit(old_buf, new_buf, self.cursor);
+			self.move_buf_end();
+		}
+	}
+	pub fn accept_hint_partial(&mut self, accept_to: usize) {
+		if let Some(hint) = self.hint.take() {
+			let accepted = &hint[..accept_to];
+			let remainder = &hint[accept_to..];
+			self.buffer.push_str(accepted);
+			self.hint = Some(remainder.to_string());
+		}
+	}
+	/// If we have a hint, then motions are able to extend into it
+	/// and partially accept pieces of it, instead of the whole thing
+	pub fn apply_motion_with_hint(&mut self, motion: MotionKind) {
+		let buffer_end = self.byte_len().saturating_sub(1);
+		flog!(DEBUG,self.hint);
+		if let Some(hint) = self.hint.take() {
+			self.buffer.push_str(&hint);
+			flog!(DEBUG,motion);
+			self.apply_motion(/*forced*/ true, motion);
+			flog!(DEBUG, self.cursor);
+			flog!(DEBUG, self.grapheme_at_cursor());
+			if self.cursor > buffer_end {
+				let remainder = if self.clamp_cursor {
+					self.slice_from((self.cursor + 1).min(self.byte_len()))
+				} else {
+					self.slice_from_cursor()
+				};
+				flog!(DEBUG,remainder);
+				if !remainder.is_empty() {
+					self.hint = Some(remainder.to_string());
+				}
+				let buffer = if self.clamp_cursor {
+					self.slice_to((self.cursor + 1).min(self.byte_len()))
+				} else {
+					self.slice_to_cursor()
+				};
+				flog!(DEBUG,buffer);
+				self.buffer = buffer.to_string();
+				flog!(DEBUG,self.hint);
+			} else {
+				let old_hint = self.slice_from(buffer_end + 1);
+				flog!(DEBUG,old_hint);
+				self.hint = Some(old_hint.to_string());
+				let buffer = self.slice_to(buffer_end + 1);
+				flog!(DEBUG,buffer);
+				self.buffer = buffer.to_string();
+			}
+		}
+	}
 	pub fn find_prev_line_pos(&mut self) -> Option<usize> {
 		if self.start_of_line() == 0 {
 			return None
@@ -799,10 +874,16 @@ impl LineBuf {
 									return self.find_from(pos, |c| CharClass::from(c) != CharClass::Whitespace)
 								}
 								if self.on_start_of_word(word) {
+									let cur_char_class = CharClass::from(self.grapheme_at_cursor()?);
 									pos += 1;
 									if pos >= self.byte_len() {
 										return None
 									}
+									let next_char = self.grapheme_at(self.next_pos(1)?)?;
+									let next_char_class = CharClass::from(next_char);
+									if cur_char_class != next_char_class && next_char_class != CharClass::Whitespace {
+										return Some(pos)
+									}
 								}
 								let cur_graph = self.grapheme_at(pos)?;
 								let diff_class_pos = self.find_from(pos, |c| is_other_class_or_ws(c, cur_graph))?;
@@ -814,15 +895,24 @@ impl LineBuf {
 								}
 							}
 							To::End => {
+								flog!(DEBUG,self.buffer);
 								if self.on_whitespace() {
 									pos = self.find_from(pos, |c| CharClass::from(c) != CharClass::Whitespace)?;
 								}
 								match self.on_end_of_word(word) {
 									true => {
+										flog!(DEBUG, "on end of word");
+										let cur_char_class = CharClass::from(self.grapheme_at_cursor()?);
 										pos += 1;
 										if pos >= self.byte_len() {
 											return None
 										}
+										let next_char = self.grapheme_at(self.next_pos(1)?)?;
+										let next_char_class = CharClass::from(next_char);
+										if cur_char_class != next_char_class && next_char_class != CharClass::Whitespace {
+											return Some(pos)
+										}
+
 										let cur_graph = self.grapheme_at(pos)?;
 										match self.find_from(pos, |c| is_other_class_or_ws(c, cur_graph)) {
 											Some(n) => {
@@ -844,7 +934,9 @@ impl LineBuf {
 										}
 									}
 									false => {
+										flog!(DEBUG, "not on end of word");
 										let cur_graph = self.grapheme_at(pos)?;
+										flog!(DEBUG,cur_graph);
 										match self.find_from(pos, |c| is_other_class_or_ws(c, cur_graph)) {
 											Some(n) => Some(n.saturating_sub(1)), // Land on char before other char class
 											None => Some(self.byte_len()) // End of buffer
@@ -863,6 +955,13 @@ impl LineBuf {
 								match self.on_start_of_word(word) {
 									true => {
 										pos = pos.checked_sub(1)?;
+										let cur_char_class = CharClass::from(self.grapheme_at_cursor()?);
+										let prev_char = self.grapheme_at(self.prev_pos(1)?)?;
+										let prev_char_class = CharClass::from(prev_char);
+										let is_diff_class = cur_char_class != prev_char_class && prev_char_class != CharClass::Whitespace;
+										if is_diff_class && self.is_start_of_word(Word::Normal, self.prev_pos(1)?) {
+												return Some(pos)
+										}
 										let prev_word_end = self.rfind_from(pos, |c| CharClass::from(c) != CharClass::Whitespace)?;
 										let cur_graph = self.grapheme_at(prev_word_end)?;
 										match self.rfind_from(prev_word_end, |c| is_other_class_or_ws(c, cur_graph)) {
@@ -885,6 +984,12 @@ impl LineBuf {
 								}
 								if self.on_end_of_word(word) {
 									pos = pos.checked_sub(1)?;
+									let cur_char_class = CharClass::from(self.grapheme_at_cursor()?);
+									let prev_char = self.grapheme_at(self.prev_pos(1)?)?;
+									let prev_char_class = CharClass::from(prev_char);
+									if cur_char_class != prev_char_class && prev_char_class != CharClass::Whitespace {
+										return Some(pos)
+									}
 								}
 								let cur_graph = self.grapheme_at(pos)?;
 								let diff_class_pos = self.rfind_from(pos, |c|is_other_class_or_ws(c, cur_graph))?;
@@ -938,7 +1043,19 @@ impl LineBuf {
 		}
 		None
 	}
+	pub fn eval_motion_with_hint(&mut self, motion: Motion) -> MotionKind {
+		let Some(hint) = self.hint.as_ref() else {
+			return MotionKind::Null
+		};
+		let buffer = self.buffer.clone();
+		self.buffer.push_str(hint);
+		let motion_eval = self.eval_motion(motion);
+		self.buffer = buffer;
+		motion_eval
+	}
 	pub fn eval_motion(&mut self, motion: Motion) -> MotionKind {
+		flog!(DEBUG,self.buffer);
+		flog!(DEBUG,motion);
 		match motion {
 			Motion::WholeLine => MotionKind::Line(0),
 			Motion::TextObj(text_obj, bound) => todo!(),
@@ -1461,6 +1578,7 @@ impl LineBuf {
 			self.undo_stack.push(edit);
 		} else {
 			let diff = Edit::diff(&old, &new, curs_pos);
+			flog!(DEBUG, diff);
 			if !diff.is_empty() {
 				self.undo_stack.push(diff);
 			}
@@ -1489,15 +1607,23 @@ impl LineBuf {
 
 		for _ in 0..verb_count.unwrap_or(1) {
 			for _ in 0..motion_count.unwrap_or(1) {
-				let motion = motion
+				let motion_eval = motion
 					.clone()
 					.map(|m| self.eval_motion(m.1))
 					.unwrap_or(MotionKind::Null);
 
+				flog!(DEBUG,self.hint);
 				if let Some(verb) = verb.clone() {
-					self.exec_verb(verb.1, motion, register)?;
+					self.exec_verb(verb.1, motion_eval, register)?;
+				} else if self.has_hint() {
+					let motion_eval = motion
+						.clone()
+						.map(|m| self.eval_motion_with_hint(m.1))
+						.unwrap_or(MotionKind::Null);
+					flog!(DEBUG, "applying motion with hint");
+					self.apply_motion_with_hint(motion_eval);
 				} else {
-					self.apply_motion(/*forced*/ false,motion);
+					self.apply_motion(/*forced*/ false,motion_eval);
 				}
 			}
 		}
@@ -1531,7 +1657,11 @@ impl LineBuf {
 
 impl Display for LineBuf {
 	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-		write!(f,"{}",self.buffer)
+		let mut full_buf = self.buffer.clone();
+		if let Some(hint) = self.hint.as_ref() {
+			full_buf.push_str(&hint.styled(Style::BrightBlack));
+		}
+		write!(f,"{}",full_buf)
 	}
 }
 

src/prompt/readline/mod.rs

@@ -1,6 +1,6 @@
 use std::time::Duration;
 
-use history::History;
+use history::{History, SearchConstraint, SearchKind};
 use keys::{KeyCode, KeyEvent, ModKeys};
 use linebuf::{strip_ansi_codes_and_escapes, LineBuf};
 use mode::{CmdReplay, ViInsert, ViMode, ViNormal, ViReplace};
@@ -65,6 +65,12 @@ impl Readline for FernVi {
 				self.handle_verbatim()?;
 				continue
 			}
+			if self.should_accept_hint(&key) {
+				self.line.accept_hint();
+				self.history.update_pending_cmd(self.line.as_str());
+				self.print_buf(true)?;
+				continue
+			}
 
 			let Some(cmd) = self.mode.handle_key(key) else {
 				continue
@@ -78,7 +84,9 @@ impl Readline for FernVi {
 			}
 
 
+
 			if cmd.should_submit() {
+				self.term.unposition_cursor()?;
 				self.term.write("\n");
 				let command = self.line.to_string();
 				if !command.is_empty() {
@@ -95,7 +103,7 @@ impl Readline for FernVi {
 			let has_changes = line != new_line;
 			flog!(DEBUG, has_changes);
 
-			if cmd.verb().is_some_and(|v| v.1.is_edit()) && has_changes {
+			if has_changes {
 				self.history.update_pending_cmd(self.line.as_str());
 			}
 
@@ -120,6 +128,16 @@ impl FernVi {
 			last_movement: None,
 		})
 	}
+	pub fn should_accept_hint(&self, event: &KeyEvent) -> bool {
+		if self.line.at_end_of_buffer() && self.line.has_hint() {
+			matches!(
+				event,
+				KeyEvent(KeyCode::Right, ModKeys::NONE)
+			)
+		} else {
+			false
+		}
+	}
 	/// Ctrl+V handler
 	pub fn handle_verbatim(&mut self) -> ShResult<()> {
 		let mut buf = [0u8; 8];
@@ -184,6 +202,10 @@ impl FernVi {
 		Ok(())
 	}
 	pub fn scroll_history(&mut self, cmd: ViCmd) {
+		if self.history.cursor_entry().is_some_and(|ent| ent.is_new()) {
+			let constraint = SearchConstraint::new(SearchKind::Prefix, self.line.to_string());
+			self.history.constrain_entries(constraint);
+		}
 		let count = &cmd.motion().unwrap().0;
 		let motion = &cmd.motion().unwrap().1;
 		flog!(DEBUG,count,motion);
@@ -244,11 +266,14 @@ impl FernVi {
 		if refresh {
 			self.term.unwrite()?;
 		}
+		let hint = self.history.get_hint();
+		self.line.set_hint(hint);
+
 		let offset = self.calculate_prompt_offset();
 		self.line.set_first_line_offset(offset);
 		self.line.update_term_dims((height,width));
 		let mut line_buf = self.prompt.clone();
-		line_buf.push_str(self.line.as_str());
+		line_buf.push_str(&self.line.to_string());
 
 		self.term.recorded_write(&line_buf, offset)?;
 		self.term.position_cursor(self.line.cursor_display_coords(width))?;