use anyhow::{Context, Error}; use std::cell::Cell; use std::future::Future; use std::path::{Component, Path, PathBuf}; use std::sync::Arc; use helix_core::{ auto_detect_line_ending, chars::{char_is_linebreak, char_is_whitespace}, history::History, syntax::{LanguageConfiguration, LOADER}, ChangeSet, Diagnostic, LineEnding, Rope, Selection, State, Syntax, Transaction, DEFAULT_LINE_ENDING, }; use crate::{DocumentId, ViewId}; use std::collections::HashMap; #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)] pub enum Mode { Normal, Select, Insert, } #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)] pub enum IndentStyle { Tabs, Spaces(u8), } pub struct Document { // rope + selection pub(crate) id: DocumentId, text: Rope, pub(crate) selections: HashMap, path: Option, /// Current editing mode. pub mode: Mode, pub restore_cursor: bool, /// Current indent style. pub indent_style: IndentStyle, syntax: Option, // /// Corresponding language scope name. Usually `source.`. pub(crate) language: Option>, /// Pending changes since last history commit. changes: ChangeSet, /// State at last commit. Used for calculating reverts. old_state: Option, /// Undo tree. // It can be used as a cell where we will take it out to get some parts of the history and put // it back as it separated from the edits. We could split out the parts manually but that will // be more troublesome. history: Cell, last_saved_revision: usize, version: i32, // should be usize? diagnostics: Vec, language_server: Option>, pub line_ending: LineEnding, } use std::fmt; impl fmt::Debug for Document { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("Document") .field("id", &self.id) .field("text", &self.text) .field("selections", &self.selections) .field("path", &self.path) .field("mode", &self.mode) .field("restore_cursor", &self.restore_cursor) .field("syntax", &self.syntax) .field("language", &self.language) .field("changes", &self.changes) .field("old_state", &self.old_state) // .field("history", &self.history) .field("last_saved_revision", &self.last_saved_revision) .field("version", &self.version) .field("diagnostics", &self.diagnostics) // .field("language_server", &self.language_server) .finish() } } /// Like std::mem::replace() except it allows the replacement value to be mapped from the /// original value. fn take_with(mut_ref: &mut T, closure: F) where F: FnOnce(T) -> T, { use std::{panic, ptr}; unsafe { let old_t = ptr::read(mut_ref); let new_t = panic::catch_unwind(panic::AssertUnwindSafe(|| closure(old_t))) .unwrap_or_else(|_| ::std::process::abort()); ptr::write(mut_ref, new_t); } } /// Normalize a path, removing things like `.` and `..`. /// /// CAUTION: This does not resolve symlinks (unlike /// [`std::fs::canonicalize`]). This may cause incorrect or surprising /// behavior at times. This should be used carefully. Unfortunately, /// [`std::fs::canonicalize`] can be hard to use correctly, since it can often /// fail, or on Windows returns annoying device paths. This is a problem Cargo /// needs to improve on. /// Copied from cargo: https://github.com/rust-lang/cargo/blob/070e459c2d8b79c5b2ac5218064e7603329c92ae/crates/cargo-util/src/paths.rs#L81 pub fn normalize_path(path: &Path) -> PathBuf { let mut components = path.components().peekable(); let mut ret = if let Some(c @ Component::Prefix(..)) = components.peek().cloned() { components.next(); PathBuf::from(c.as_os_str()) } else { PathBuf::new() }; for component in components { match component { Component::Prefix(..) => unreachable!(), Component::RootDir => { ret.push(component.as_os_str()); } Component::CurDir => {} Component::ParentDir => { ret.pop(); } Component::Normal(c) => { ret.push(c); } } } ret } // Returns the canonical, absolute form of a path with all intermediate components normalized. // // This function is used instead of `std::fs::canonicalize` because we don't want to verify // here if the path exists, just normalize it's components. pub fn canonicalize_path(path: &Path) -> std::io::Result { std::env::current_dir().map(|current_dir| normalize_path(¤t_dir.join(path))) } use helix_lsp::lsp; use url::Url; impl Document { pub fn new(text: Rope) -> Self { let changes = ChangeSet::new(&text); let old_state = None; Self { id: DocumentId::default(), path: None, text, selections: HashMap::default(), indent_style: IndentStyle::Spaces(4), mode: Mode::Normal, restore_cursor: false, syntax: None, language: None, changes, old_state, diagnostics: Vec::new(), version: 0, history: Cell::new(History::default()), last_saved_revision: 0, language_server: None, line_ending: DEFAULT_LINE_ENDING, } } // TODO: async fn? pub fn load(path: PathBuf) -> Result { use std::{fs::File, io::BufReader}; let doc = if !path.exists() { Rope::from("\n") } else { let file = File::open(&path).context(format!("unable to open {:?}", path))?; let mut doc = Rope::from_reader(BufReader::new(file))?; // add missing newline at the end of file if doc.len_bytes() == 0 || doc.byte(doc.len_bytes() - 1) != b'\n' { doc.insert_char(doc.len_chars(), '\n'); } doc }; // search for line endings let line_ending = auto_detect_line_ending(&doc).unwrap_or(DEFAULT_LINE_ENDING); let mut doc = Self::new(doc); // set the path and try detecting the language doc.set_path(&path)?; doc.detect_indent_style(); doc.set_line_ending(line_ending); Ok(doc) } // TODO: remove view_id dependency here pub fn format(&mut self, view_id: ViewId) { if let Some(language_server) = self.language_server() { // TODO: await, no blocking let transaction = helix_lsp::block_on( language_server .text_document_formatting(self.identifier(), lsp::FormattingOptions::default()), ) .map(|edits| { helix_lsp::util::generate_transaction_from_edits( self.text(), edits, language_server.offset_encoding(), ) }); if let Ok(transaction) = transaction { self.apply(&transaction, view_id); self.append_changes_to_history(view_id); } } } // TODO: do we need some way of ensuring two save operations on the same doc can't run at once? // or is that handled by the OS/async layer pub fn save(&mut self) -> impl Future> { // we clone and move text + path into the future so that we asynchronously save the current // state without blocking any further edits. let text = self.text().clone(); let path = self.path.clone().expect("Can't save with no path set!"); // TODO: handle no path let identifier = self.identifier(); // TODO: mark changes up to now as saved let language_server = self.language_server.clone(); // reset the modified flag let history = self.history.take(); self.last_saved_revision = history.current_revision(); self.history.set(history); async move { use tokio::{fs::File, io::AsyncWriteExt}; if let Some(parent) = path.parent() { // TODO: display a prompt asking the user if the directories should be created if !parent.exists() { return Err(Error::msg( "can't save file, parent directory does not exist", )); } } let mut file = File::create(path).await?; // write all the rope chunks to file for chunk in text.chunks() { file.write_all(chunk.as_bytes()).await?; } // TODO: flush? if let Some(language_server) = language_server { language_server .text_document_did_save(identifier, &text) .await?; } Ok(()) } } fn detect_language(&mut self) { if let Some(path) = self.path() { let loader = LOADER.get().unwrap(); let language_config = loader.language_config_for_file_name(path); let scopes = loader.scopes(); self.set_language(language_config, scopes); } } fn detect_indent_style(&mut self) { // Build a histogram of the indentation *increases* between // subsequent lines, ignoring lines that are all whitespace. // // Index 0 is for tabs, the rest are 1-8 spaces. let histogram: [usize; 9] = { let mut histogram = [0; 9]; let mut prev_line_is_tabs = false; let mut prev_line_leading_count = 0usize; // Loop through the lines, checking for and recording indentation // increases as we go. 'outer: for line in self.text.lines().take(1000) { let mut c_iter = line.chars(); // Is first character a tab or space? let is_tabs = match c_iter.next() { Some('\t') => true, Some(' ') => false, // Ignore blank lines. Some(c) if char_is_linebreak(c) => continue, _ => { prev_line_is_tabs = false; prev_line_leading_count = 0; continue; } }; // Count the line's total leading tab/space characters. let mut leading_count = 1; let mut count_is_done = false; for c in c_iter { match c { '\t' if is_tabs && !count_is_done => leading_count += 1, ' ' if !is_tabs && !count_is_done => leading_count += 1, // We stop counting if we hit whitespace that doesn't // qualify as indent or doesn't match the leading // whitespace, but we don't exit the loop yet because // we still want to determine if the line is blank. c if char_is_whitespace(c) => count_is_done = true, // Ignore blank lines. c if char_is_linebreak(c) => continue 'outer, _ => break, } // Bound the worst-case execution time for weird text files. if leading_count > 256 { continue 'outer; } } // If there was an increase in indentation over the previous // line, update the histogram with that increase. if (prev_line_is_tabs == is_tabs || prev_line_leading_count == 0) && prev_line_leading_count < leading_count { if is_tabs { histogram[0] += 1; } else { let amount = leading_count - prev_line_leading_count; if amount <= 8 { histogram[amount] += 1; } } } // Store this line's leading whitespace info for use with // the next line. prev_line_is_tabs = is_tabs; prev_line_leading_count = leading_count; } // Give more weight to tabs, because their presence is a very // strong indicator. histogram[0] *= 2; histogram }; // Find the most frequent indent, its frequency, and the frequency of // the next-most frequent indent. let indent = histogram .iter() .enumerate() .max_by_key(|kv| kv.1) .unwrap() .0; let indent_freq = histogram[indent]; let indent_freq_2 = *histogram .iter() .enumerate() .filter(|kv| kv.0 != indent) .map(|kv| kv.1) .max() .unwrap(); // Use the auto-detected result if we're confident enough in its // accuracy, based on some heuristics. Otherwise fall back to // the language-based setting. if indent_freq >= 1 && (indent_freq_2 as f64 / indent_freq as f64) < 0.66 { // Use the auto-detected setting. self.indent_style = match indent { 0 => IndentStyle::Tabs, _ => IndentStyle::Spaces(indent as u8), }; } else { // Fall back to language-based setting. let indent = self .language .as_ref() .and_then(|config| config.indent.as_ref()) .map_or(" ", |config| config.unit.as_str()); // fallback to 2 spaces self.indent_style = if indent.starts_with(' ') { IndentStyle::Spaces(indent.len() as u8) } else { IndentStyle::Tabs }; } } pub fn set_path(&mut self, path: &Path) -> Result<(), std::io::Error> { let path = canonicalize_path(path)?; // if parent doesn't exist we still want to open the document // and error out when document is saved self.path = Some(path); // try detecting the language based on filepath self.detect_language(); Ok(()) } pub fn set_language( &mut self, language_config: Option>, scopes: &[String], ) { if let Some(language_config) = language_config { if let Some(highlight_config) = language_config.highlight_config(scopes) { let syntax = Syntax::new(&self.text, highlight_config); self.syntax = Some(syntax); // TODO: config.configure(scopes) is now delayed, is that ok? } self.language = Some(language_config); } else { self.syntax = None; self.language = None; }; } pub fn set_language2(&mut self, scope: &str) { let loader = LOADER.get().unwrap(); let language_config = loader.language_config_for_scope(scope); let scopes = loader.scopes(); self.set_language(language_config, scopes); } pub fn set_language_server(&mut self, language_server: Option>) { self.language_server = language_server; } pub fn set_selection(&mut self, view_id: ViewId, selection: Selection) { // TODO: use a transaction? self.selections.insert(view_id, selection); } pub fn set_line_ending(&mut self, line_ending: LineEnding) { self.line_ending = line_ending; } fn _apply(&mut self, transaction: &Transaction, view_id: ViewId) -> bool { let old_doc = self.text().clone(); let success = transaction.changes().apply(&mut self.text); if success { // update the selection: either take the selection specified in the transaction, or map the // current selection through changes. let selection = transaction .selection() .cloned() .unwrap_or_else(|| self.selection(view_id).clone().map(transaction.changes())); self.set_selection(view_id, selection); } if !transaction.changes().is_empty() { self.version += 1; // update tree-sitter syntax tree if let Some(syntax) = &mut self.syntax { // TODO: no unwrap syntax .update(&old_doc, &self.text, transaction.changes()) .unwrap(); } // map state.diagnostics over changes::map_pos too // NOTE: seems to do nothing since the language server resends diagnostics on each edit // for diagnostic in &mut self.diagnostics { // use helix_core::Assoc; // let changes = transaction.changes(); // diagnostic.range.start = changes.map_pos(diagnostic.range.start, Assoc::After); // diagnostic.range.end = changes.map_pos(diagnostic.range.end, Assoc::After); // diagnostic.line = self.text.char_to_line(diagnostic.range.start); // } // emit lsp notification if let Some(language_server) = &self.language_server { let notify = language_server.text_document_did_change( self.versioned_identifier(), &old_doc, self.text(), transaction.changes(), ); if let Some(notify) = notify { tokio::spawn(notify); } //.expect("failed to emit textDocument/didChange"); } } success } pub fn apply(&mut self, transaction: &Transaction, view_id: ViewId) -> bool { // store the state just before any changes are made. This allows us to undo to the // state just before a transaction was applied. if self.changes.is_empty() && !transaction.changes().is_empty() { self.old_state = Some(State { doc: self.text.clone(), selection: self.selection(view_id).clone(), }); } let success = self._apply(transaction, view_id); if !transaction.changes().is_empty() { // Compose this transaction with the previous one take_with(&mut self.changes, |changes| { changes.compose(transaction.changes().clone()) }); } success } pub fn undo(&mut self, view_id: ViewId) { let mut history = self.history.take(); let success = if let Some(transaction) = history.undo() { self._apply(&transaction, view_id) } else { false }; self.history.set(history); if success { // reset changeset to fix len self.changes = ChangeSet::new(self.text()); } } pub fn redo(&mut self, view_id: ViewId) { let mut history = self.history.take(); let success = if let Some(transaction) = history.redo() { self._apply(&transaction, view_id) } else { false }; self.history.set(history); if success { // reset changeset to fix len self.changes = ChangeSet::new(self.text()); } } pub fn earlier(&mut self, view_id: ViewId, uk: helix_core::history::UndoKind) { let txns = self.history.get_mut().earlier(uk); for txn in txns { self._apply(&txn, view_id); } } pub fn later(&mut self, view_id: ViewId, uk: helix_core::history::UndoKind) { let txns = self.history.get_mut().later(uk); for txn in txns { self._apply(&txn, view_id); } } pub fn append_changes_to_history(&mut self, view_id: ViewId) { if self.changes.is_empty() { return; } let new_changeset = ChangeSet::new(self.text()); let changes = std::mem::replace(&mut self.changes, new_changeset); // Instead of doing this messy merge we could always commit, and based on transaction // annotations either add a new layer or compose into the previous one. let transaction = Transaction::from(changes).with_selection(self.selection(view_id).clone()); // HAXX: we need to reconstruct the state as it was before the changes.. let old_state = self.old_state.take().expect("no old_state available"); let mut history = self.history.take(); history.commit_revision(&transaction, &old_state); self.history.set(history); } #[inline] pub fn id(&self) -> DocumentId { self.id } #[inline] pub fn is_modified(&self) -> bool { let history = self.history.take(); let current_revision = history.current_revision(); self.history.set(history); current_revision != self.last_saved_revision || !self.changes.is_empty() } #[inline] pub fn mode(&self) -> Mode { self.mode } #[inline] /// Corresponding language scope name. Usually `source.`. pub fn language(&self) -> Option<&str> { self.language .as_ref() .map(|language| language.scope.as_str()) } #[inline] pub fn language_config(&self) -> Option<&LanguageConfiguration> { self.language.as_deref() } #[inline] /// Current document version, incremented at each change. pub fn version(&self) -> i32 { self.version } pub fn language_server(&self) -> Option<&helix_lsp::Client> { self.language_server.as_deref() } /// Tree-sitter AST tree pub fn syntax(&self) -> Option<&Syntax> { self.syntax.as_ref() } /// Tab size in columns. pub fn tab_width(&self) -> usize { self.language .as_ref() .and_then(|config| config.indent.as_ref()) .map_or(4, |config| config.tab_width) // fallback to 4 columns } /// Returns a string containing a single level of indentation. /// /// TODO: we might not need this function anymore, since the information /// is conveniently available in `Document::indent_style` now. pub fn indent_unit(&self) -> &'static str { match self.indent_style { IndentStyle::Tabs => "\t", IndentStyle::Spaces(1) => " ", IndentStyle::Spaces(2) => " ", IndentStyle::Spaces(3) => " ", IndentStyle::Spaces(4) => " ", IndentStyle::Spaces(5) => " ", IndentStyle::Spaces(6) => " ", IndentStyle::Spaces(7) => " ", IndentStyle::Spaces(8) => " ", // Unsupported indentation style. This should never happen, // but just in case fall back to two spaces. _ => " ", } } #[inline] /// File path on disk. pub fn path(&self) -> Option<&PathBuf> { self.path.as_ref() } pub fn url(&self) -> Option { self.path().map(|path| Url::from_file_path(path).unwrap()) } pub fn text(&self) -> &Rope { &self.text } pub fn selection(&self, view_id: ViewId) -> &Selection { &self.selections[&view_id] } pub fn relative_path(&self) -> Option<&Path> { let cwdir = std::env::current_dir().expect("couldn't determine current directory"); self.path .as_ref() .map(|path| path.strip_prefix(cwdir).unwrap_or(path)) } // pub fn slice(&self, range: R) -> RopeSlice where R: RangeBounds { // self.state.doc.slice // } // transact(Fn) ? // -- LSP methods pub fn identifier(&self) -> lsp::TextDocumentIdentifier { lsp::TextDocumentIdentifier::new(self.url().unwrap()) } pub fn versioned_identifier(&self) -> lsp::VersionedTextDocumentIdentifier { lsp::VersionedTextDocumentIdentifier::new(self.url().unwrap(), self.version) } pub fn diagnostics(&self) -> &[Diagnostic] { &self.diagnostics } pub fn set_diagnostics(&mut self, diagnostics: Vec) { self.diagnostics = diagnostics; } pub fn line_ending(&self) -> &'static str { match self.line_ending { LineEnding::Crlf => "\u{000D}\u{000A}", LineEnding::LF => "\u{000A}", LineEnding::Nel => "\u{0085}", LineEnding::LS => "\u{2028}", LineEnding::CR => "\u{000D}", _ => panic!( "Unexpected line ending: {:?}, expected Crlf, LF, CR, Nel, or LS.", self.line_ending ), } } } #[cfg(test)] mod test { use super::*; #[test] fn changeset_to_changes() { use helix_lsp::{lsp, Client, OffsetEncoding}; let text = Rope::from("hello"); let mut doc = Document::new(text); let view = ViewId::default(); doc.set_selection(view, Selection::single(5, 5)); // insert let transaction = Transaction::insert(doc.text(), doc.selection(view), " world".into()); let old_doc = doc.text().clone(); doc.apply(&transaction, view); let changes = Client::changeset_to_changes( &old_doc, doc.text(), transaction.changes(), OffsetEncoding::Utf8, ); assert_eq!( changes, &[lsp::TextDocumentContentChangeEvent { range: Some(lsp::Range::new( lsp::Position::new(0, 5), lsp::Position::new(0, 5) )), text: " world".into(), range_length: None, }] ); // delete let transaction = transaction.invert(&old_doc); let old_doc = doc.text().clone(); doc.apply(&transaction, view); let changes = Client::changeset_to_changes( &old_doc, doc.text(), transaction.changes(), OffsetEncoding::Utf8, ); // line: 0-based. // col: 0-based, gaps between chars. // 0 1 2 3 4 5 6 7 8 9 0 1 // |h|e|l|l|o| |w|o|r|l|d| // ------------- // (0, 5)-(0, 11) assert_eq!( changes, &[lsp::TextDocumentContentChangeEvent { range: Some(lsp::Range::new( lsp::Position::new(0, 5), lsp::Position::new(0, 11) )), text: "".into(), range_length: None, }] ); // replace // also tests that changes are layered, positions depend on previous changes. doc.set_selection(view, Selection::single(0, 5)); let transaction = Transaction::change( doc.text(), vec![(0, 2, Some("aei".into())), (3, 5, Some("ou".into()))].into_iter(), ); // aeilou let old_doc = doc.text().clone(); doc.apply(&transaction, view); let changes = Client::changeset_to_changes( &old_doc, doc.text(), transaction.changes(), OffsetEncoding::Utf8, ); assert_eq!( changes, &[ // 0 1 2 3 4 5 // |h|e|l|l|o| // ---- // // aeillo lsp::TextDocumentContentChangeEvent { range: Some(lsp::Range::new( lsp::Position::new(0, 0), lsp::Position::new(0, 2) )), text: "aei".into(), range_length: None, }, // 0 1 2 3 4 5 6 // |a|e|i|l|l|o| // ----- // // aeilou lsp::TextDocumentContentChangeEvent { range: Some(lsp::Range::new( lsp::Position::new(0, 4), lsp::Position::new(0, 6) )), text: "ou".into(), range_length: None, } ] ); } }