Introduce History trait

Cargo.toml

@@ -29,7 +29,8 @@ cfg-if = "1.0"
 # https://rustsec.org/advisories/RUSTSEC-2020-0053.html
 dirs-next = { version = "2.0", optional = true }
 # For History
-fd-lock = "3.0.0"
+fd-lock = { version = "3.0.0", optional = true }
+rusqlite = { version = "0.28.0", optional = true, default-features = false, features = ["bundled", "backup"] }
 libc = "0.2"
 log = "0.4"
 unicode-width = "0.1"
@@ -59,14 +60,20 @@ assert_matches = "1.2"
 rustyline-derive = { version = "0.7.0", path = "rustyline-derive" }
 
 [features]
-default = ["custom-bindings", "with-dirs"]
+default = ["custom-bindings", "with-dirs", "with-file-history"]
 custom-bindings = ["radix_trie"]
 with-dirs = ["dirs-next"]
+with-file-history = ["fd-lock"]
+with-sqlite-history = ["rusqlite"]
 with-fuzzy = ["skim"]
 case_insensitive_history_search = ["regex"]
 
+[[example]]
+name = "sqlite_history"
+required-features = ["with-sqlite-history"]
+
 [package.metadata.docs.rs]
-features = ["custom-bindings", "with-dirs", "with-fuzzy"]
+features = ["custom-bindings", "with-dirs", "with-file-history", "with-fuzzy"]
 all-features = false
 no-default-features = true
 default-target = "x86_64-unknown-linux-gnu"

README.md

@@ -24,11 +24,12 @@ Readline implementation in Rust that is based on [Antirez' Linenoise](https://gi
 
 ```rust
 use rustyline::error::ReadlineError;
-use rustyline::{Editor, Result};
+use rustyline::{DefaultEditor, Result};
 
 fn main() -> Result<()> {
     // `()` can be used when no completer is required
-    let mut rl = Editor::<()>::new()?;
+    let mut rl = DefaultEditor::new()?;
+    #[cfg(feature = "with-file-history")]
     if rl.load_history("history.txt").is_err() {
         println!("No previous history.");
     }
@@ -53,6 +54,7 @@ fn main() -> Result<()> {
             }
         }
     }
+    #[cfg(feature = "with-file-history")]
     rl.save_history("history.txt")
 }
 ```

examples/custom_key_bindings.rs

@@ -2,6 +2,7 @@ use std::borrow::Cow::{self, Borrowed, Owned};
 
 use rustyline::highlight::Highlighter;
 use rustyline::hint::HistoryHinter;
+use rustyline::history::DefaultHistory;
 use rustyline::{
     Cmd, ConditionalEventHandler, Editor, Event, EventContext, EventHandler, KeyEvent, RepeatCount,
     Result,
@@ -85,7 +86,7 @@ impl ConditionalEventHandler for TabEventHandler {
 }
 
 fn main() -> Result<()> {
-    let mut rl = Editor::<MyHelper>::new()?;
+    let mut rl = Editor::<MyHelper, DefaultHistory>::new()?;
     rl.set_helper(Some(MyHelper(HistoryHinter {})));
 
     let ceh = Box::new(CompleteHintHandler);
@@ -102,7 +103,7 @@ fn main() -> Result<()> {
 
     loop {
         let line = rl.readline("> ")?;
-        rl.add_history_entry(line.as_str());
+        rl.add_history_entry(line.as_str())?;
         println!("Line: {line}");
     }
 }

examples/diy_hints.rs

@@ -1,6 +1,7 @@
 use std::collections::HashSet;
 
 use rustyline::hint::{Hint, Hinter};
+use rustyline::history::DefaultHistory;
 use rustyline::Context;
 use rustyline::{Editor, Result};
 use rustyline_derive::{Completer, Helper, Highlighter, Validator};
@@ -85,7 +86,7 @@ fn main() -> Result<()> {
     println!("This is a DIY hint hack of rustyline");
     let h = DIYHinter { hints: diy_hints() };
 
-    let mut rl: Editor<DIYHinter> = Editor::new()?;
+    let mut rl: Editor<DIYHinter, DefaultHistory> = Editor::new()?;
     rl.set_helper(Some(h));
 
     loop {

examples/example.rs

@@ -76,7 +76,7 @@ fn main() -> rustyline::Result<()> {
         let readline = rl.readline(&p);
         match readline {
             Ok(line) => {
-                rl.add_history_entry(line.as_str());
+                rl.add_history_entry(line.as_str())?;
                 println!("Line: {line}");
             }
             Err(ReadlineError::Interrupted) => {

examples/external_print.rs

@@ -3,10 +3,10 @@ use std::time::Duration;
 
 use rand::{thread_rng, Rng};
 
-use rustyline::{Editor, ExternalPrinter, Result};
+use rustyline::{DefaultEditor, ExternalPrinter, Result};
 
 fn main() -> Result<()> {
-    let mut rl = Editor::<()>::new()?;
+    let mut rl = DefaultEditor::new()?;
     let mut printer = rl.create_external_printer()?;
     thread::spawn(move || {
         let mut rng = thread_rng();
@@ -23,7 +23,7 @@ fn main() -> Result<()> {
 
     loop {
         let line = rl.readline("> ")?;
-        rl.add_history_entry(line.as_str());
+        rl.add_history_entry(line.as_str())?;
         println!("Line: {line}");
     }
 }

examples/minimal.rs

@@ -1,9 +1,9 @@
-use rustyline::{Editor, Result};
+use rustyline::{DefaultEditor, Result};
 
 /// Minimal REPL
 fn main() -> Result<()> {
     env_logger::init();
-    let mut rl = Editor::<()>::new()?;
+    let mut rl = DefaultEditor::new()?;
     loop {
         let line = rl.readline("> ")?; // read
         println!("Line: {line}"); // eval / print

examples/numeric_input.rs

@@ -1,6 +1,6 @@
 use rustyline::{
-    Cmd, ConditionalEventHandler, Editor, Event, EventContext, EventHandler, KeyCode, KeyEvent,
-    Modifiers, RepeatCount, Result,
+    Cmd, ConditionalEventHandler, DefaultEditor, Event, EventContext, EventHandler, KeyCode,
+    KeyEvent, Modifiers, RepeatCount, Result,
 };
 
 struct FilteringEventHandler;
@@ -19,7 +19,7 @@ impl ConditionalEventHandler for FilteringEventHandler {
 }
 
 fn main() -> Result<()> {
-    let mut rl = Editor::<()>::new()?;
+    let mut rl = DefaultEditor::new()?;
 
     rl.bind_sequence(
         Event::Any,

examples/sqlite_history.rs

@@ -0,0 +1,17 @@
+use rustyline::{Config, Editor, Result};
+
+fn main() -> Result<()> {
+    let config = Config::builder().auto_add_history(true).build();
+    let history = if false {
+        // memory
+        rustyline::sqlite_history::SQLiteHistory::with_config(config)?
+    } else {
+        // file
+        rustyline::sqlite_history::SQLiteHistory::open(config, "history.sqlite3")?
+    };
+    let mut rl: Editor<(), _> = Editor::with_history(config, history)?;
+    loop {
+        let line = rl.readline("> ")?;
+        println!("{line}");
+    }
+}

src/config.rs

@@ -1,4 +1,5 @@
 //! Customize line editor
+use crate::Result;
 use std::default::Default;
 
 /// User preferences
@@ -322,20 +323,18 @@ impl Builder {
     }
 
     /// Set the maximum length for the history.
-    #[must_use]
-    pub fn max_history_size(mut self, max_size: usize) -> Self {
-        self.set_max_history_size(max_size);
-        self
+    pub fn max_history_size(mut self, max_size: usize) -> Result<Self> {
+        self.set_max_history_size(max_size)?;
+        Ok(self)
     }
 
     /// Tell if lines which match the previous history entry are saved or not
     /// in the history list.
     ///
     /// By default, they are ignored.
-    #[must_use]
-    pub fn history_ignore_dups(mut self, yes: bool) -> Self {
-        self.set_history_ignore_dups(yes);
-        self
+    pub fn history_ignore_dups(mut self, yes: bool) -> Result<Self> {
+        self.set_history_ignore_dups(yes)?;
+        Ok(self)
     }
 
     /// Tell if lines which begin with a space character are saved or not in
@@ -470,16 +469,18 @@ pub trait Configurer {
     fn config_mut(&mut self) -> &mut Config;
 
     /// Set the maximum length for the history.
-    fn set_max_history_size(&mut self, max_size: usize) {
+    fn set_max_history_size(&mut self, max_size: usize) -> Result<()> {
         self.config_mut().set_max_history_size(max_size);
+        Ok(())
     }
 
     /// Tell if lines which match the previous history entry are saved or not
     /// in the history list.
     ///
     /// By default, they are ignored.
-    fn set_history_ignore_dups(&mut self, yes: bool) {
+    fn set_history_ignore_dups(&mut self, yes: bool) -> Result<()> {
         self.config_mut().set_history_ignore_dups(yes);
+        Ok(())
     }
 
     /// Tell if lines which begin with a space character are saved or not in

src/edit.rs

@@ -643,16 +643,22 @@ impl<'out, 'prompt, H: Helper> State<'out, 'prompt, H> {
         } else if self.ctx.history_index == 0 && prev {
             return Ok(());
         }
-        if prev {
-            self.ctx.history_index -= 1;
+        let (idx, dir) = if prev {
+            (self.ctx.history_index - 1, SearchDirection::Reverse)
         } else {
             self.ctx.history_index += 1;
-        }
-        if self.ctx.history_index < history.len() {
-            let buf = history.get(self.ctx.history_index).unwrap();
-            self.changes.begin();
-            self.line.update(buf, buf.len(), &mut self.changes);
-            self.changes.end();
+            (self.ctx.history_index, SearchDirection::Forward)
+        };
+        if idx < history.len() {
+            if let Some(r) = history.get(idx, dir)? {
+                let buf = r.entry;
+                self.ctx.history_index = r.idx;
+                self.changes.begin();
+                self.line.update(&buf, buf.len(), &mut self.changes);
+                self.changes.end();
+            } else {
+                return Ok(());
+            }
         } else {
             // Restore current edited line
             self.restore();
@@ -680,10 +686,10 @@ impl<'out, 'prompt, H: Helper> State<'out, 'prompt, H> {
             &self.line.as_str()[..self.line.pos()],
             self.ctx.history_index,
             dir,
-        ) {
+        )? {
             self.ctx.history_index = sr.idx;
             self.changes.begin();
-            self.line.update(sr.entry, sr.pos, &mut self.changes);
+            self.line.update(&sr.entry, sr.pos, &mut self.changes);
             self.changes.end();
             self.refresh_line()
         } else {
@@ -708,11 +714,15 @@ impl<'out, 'prompt, H: Helper> State<'out, 'prompt, H> {
             return Ok(());
         }
         if first {
-            self.ctx.history_index = 0;
-            let buf = history.get(self.ctx.history_index).unwrap();
-            self.changes.begin();
-            self.line.update(buf, buf.len(), &mut self.changes);
-            self.changes.end();
+            if let Some(r) = history.get(0, SearchDirection::Forward)? {
+                let buf = r.entry;
+                self.ctx.history_index = r.idx;
+                self.changes.begin();
+                self.line.update(&buf, buf.len(), &mut self.changes);
+                self.changes.end();
+            } else {
+                return Ok(());
+            }
         } else {
             self.ctx.history_index = history.len();
             // Restore current edited line
@@ -737,7 +747,7 @@ pub fn init_state<'out, H: Helper>(
     line: &str,
     pos: usize,
     helper: Option<&'out H>,
-    history: &'out crate::history::History,
+    history: &'out crate::history::DefaultHistory,
 ) -> State<'out, 'static, H> {
     State {
         out,
@@ -758,15 +768,15 @@ pub fn init_state<'out, H: Helper>(
 #[cfg(test)]
 mod test {
     use super::init_state;
-    use crate::history::History;
+    use crate::history::{DefaultHistory, History};
     use crate::tty::Sink;
 
     #[test]
     fn edit_history_next() {
         let mut out = Sink::default();
-        let mut history = History::new();
-        history.add("line0");
-        history.add("line1");
+        let mut history = DefaultHistory::new();
+        history.add("line0").unwrap();
+        history.add("line1").unwrap();
         let line = "current edited line";
         let helper: Option<()> = None;
         let mut s = init_state(&mut out, line, 6, helper.as_ref(), &history);

src/error.rs

@@ -29,6 +29,9 @@ pub enum ReadlineError {
     /// Something went wrong calling a Windows API
     #[cfg(windows)]
     SystemError(clipboard_win::SystemError),
+    /// Error related to SQLite history backend
+    #[cfg(feature = "with-sqlite-history")]
+    SQLiteError(rusqlite::Error),
 }
 
 impl fmt::Display for ReadlineError {
@@ -44,6 +47,8 @@ impl fmt::Display for ReadlineError {
             ReadlineError::Decode(ref err) => err.fmt(f),
             #[cfg(windows)]
             ReadlineError::SystemError(ref err) => err.fmt(f),
+            #[cfg(feature = "with-sqlite-history")]
+            ReadlineError::SQLiteError(ref err) => err.fmt(f),
         }
     }
 }
@@ -61,6 +66,8 @@ impl Error for ReadlineError {
             ReadlineError::Decode(ref err) => Some(err),
             #[cfg(windows)]
             ReadlineError::SystemError(_) => None,
+            #[cfg(feature = "with-sqlite-history")]
+            ReadlineError::SQLiteError(ref err) => Some(err),
         }
     }
 }
@@ -131,3 +138,10 @@ impl From<clipboard_win::SystemError> for ReadlineError {
         ReadlineError::SystemError(err)
     }
 }
+
+#[cfg(feature = "with-sqlite-history")]
+impl From<rusqlite::Error> for ReadlineError {
+    fn from(err: rusqlite::Error) -> Self {
+        ReadlineError::SQLiteError(err)
+    }
+}

src/hint.rs

@@ -67,6 +67,7 @@ impl Hinter for HistoryHinter {
         if let Some(sr) = ctx
             .history
             .starts_with(line, start, SearchDirection::Reverse)
+            .unwrap_or(None)
         {
             if sr.entry == line {
                 return None;
@@ -80,12 +81,12 @@ impl Hinter for HistoryHinter {
 #[cfg(test)]
 mod test {
     use super::{Hinter, HistoryHinter};
-    use crate::history::History;
+    use crate::history::DefaultHistory;
     use crate::Context;
 
     #[test]
     pub fn empty_history() {
-        let history = History::new();
+        let history = DefaultHistory::new();
         let ctx = Context::new(&history);
         let hinter = HistoryHinter {};
         let hint = hinter.hint("test", 4, &ctx);