Merge pull request #492 from gwenn/conditional_binding2

Conditional binding

Cargo.toml

@@ -20,14 +20,20 @@ members = ["rustyline-derive"]
 [dependencies]
 bitflags = "1.2"
 cfg-if = "1.0"
+# For file completion
 # https://rustsec.org/advisories/RUSTSEC-2020-0053.html
 dirs-next = { version = "2.0", optional = true }
+# For History
 fs2 = "0.4"
 libc = "0.2"
 log = "0.4"
 unicode-width = "0.1"
 unicode-segmentation = "1.0"
 memchr = "2.0"
+# For custom bindings
+# https://rustsec.org/advisories/RUSTSEC-2021-0003.html
+smallvec = "1.6.1"
+radix_trie = "0.2"
 
 [target.'cfg(unix)'.dependencies]
 nix = "0.20"

examples/custom_key_bindings.rs

@@ -0,0 +1,110 @@
+use smallvec::smallvec;
+use std::borrow::Cow::{self, Borrowed, Owned};
+
+use rustyline::highlight::Highlighter;
+use rustyline::hint::{Hinter, HistoryHinter};
+use rustyline::{
+    Cmd, ConditionalEventHandler, Context, Editor, Event, EventContext, EventHandler, KeyEvent,
+    RepeatCount,
+};
+use rustyline_derive::{Completer, Helper, Validator};
+
+#[derive(Completer, Helper, Validator)]
+struct MyHelper(HistoryHinter);
+
+impl Hinter for MyHelper {
+    type Hint = String;
+
+    fn hint(&self, line: &str, pos: usize, ctx: &Context<'_>) -> Option<String> {
+        self.0.hint(line, pos, ctx)
+    }
+}
+
+impl Highlighter for MyHelper {
+    fn highlight_prompt<'b, 's: 'b, 'p: 'b>(
+        &'s self,
+        prompt: &'p str,
+        default: bool,
+    ) -> Cow<'b, str> {
+        if default {
+            Owned(format!("\x1b[1;32m{}\x1b[m", prompt))
+        } else {
+            Borrowed(prompt)
+        }
+    }
+
+    fn highlight_hint<'h>(&self, hint: &'h str) -> Cow<'h, str> {
+        Owned(format!("\x1b[1m{}\x1b[m", hint))
+    }
+}
+
+#[derive(Clone)]
+struct CompleteHintHandler;
+impl ConditionalEventHandler for CompleteHintHandler {
+    fn handle(&self, evt: &Event, _: RepeatCount, _: bool, ctx: &EventContext) -> Option<Cmd> {
+        if !ctx.has_hint() {
+            return None; // default
+        }
+        if let Some(k) = evt.get(0) {
+            #[allow(clippy::if_same_then_else)]
+            if *k == KeyEvent::ctrl('E') {
+                Some(Cmd::CompleteHint)
+            } else if *k == KeyEvent::alt('f') && ctx.line().len() == ctx.pos() {
+                Some(Cmd::CompleteHint) // TODO give access to hint
+            } else {
+                None
+            }
+        } else {
+            unreachable!()
+        }
+    }
+}
+
+struct TabEventHandler;
+impl ConditionalEventHandler for TabEventHandler {
+    fn handle(&self, evt: &Event, n: RepeatCount, _: bool, ctx: &EventContext) -> Option<Cmd> {
+        debug_assert_eq!(*evt, Event::from(KeyEvent::from('\t')));
+        if ctx.line()[..ctx.pos()]
+            .chars()
+            .rev()
+            .next()
+            .filter(|c| c.is_whitespace())
+            .is_some()
+        {
+            Some(Cmd::SelfInsert(n, '\t'))
+        } else {
+            None // default complete
+        }
+    }
+}
+
+fn main() {
+    let mut rl = Editor::<MyHelper>::new();
+    rl.set_helper(Some(MyHelper(HistoryHinter {})));
+
+    let ceh = Box::new(CompleteHintHandler);
+    rl.bind_sequence(KeyEvent::ctrl('E'), EventHandler::Conditional(ceh.clone()));
+    rl.bind_sequence(KeyEvent::alt('f'), EventHandler::Conditional(ceh));
+    rl.bind_sequence(
+        KeyEvent::from('\t'),
+        EventHandler::Conditional(Box::new(TabEventHandler)),
+    );
+    rl.bind_sequence(
+        Event::KeySeq(smallvec![KeyEvent::ctrl('X'), KeyEvent::ctrl('E')]),
+        EventHandler::Simple(Cmd::Suspend), // TODO external editor
+    );
+
+    loop {
+        let readline = rl.readline("> ");
+        match readline {
+            Ok(line) => {
+                rl.add_history_entry(line.as_str());
+                println!("Line: {}", line);
+            }
+            Err(err) => {
+                println!("Error: {:?}", err);
+                break;
+            }
+        }
+    }
+}

examples/example.rs

@@ -97,8 +97,8 @@ fn main() -> rustyline::Result<()> {
     };
     let mut rl = Editor::with_config(config);
     rl.set_helper(Some(h));
-    rl.bind_sequence(KeyEvent::alt('N'), Cmd::HistorySearchForward);
-    rl.bind_sequence(KeyEvent::alt('P'), Cmd::HistorySearchBackward);
+    rl.bind_sequence(KeyEvent::alt('n'), Cmd::HistorySearchForward);
+    rl.bind_sequence(KeyEvent::alt('p'), Cmd::HistorySearchBackward);
     if rl.load_history("history.txt").is_err() {
         println!("No previous history.");
     }

examples/numeric_input.rs

@@ -0,0 +1,41 @@
+use rustyline::{
+    Cmd, ConditionalEventHandler, Editor, Event, EventContext, EventHandler, KeyCode, KeyEvent,
+    Modifiers, RepeatCount,
+};
+
+struct FilteringEventHandler;
+impl ConditionalEventHandler for FilteringEventHandler {
+    fn handle(&self, evt: &Event, _: RepeatCount, _: bool, _: &EventContext) -> Option<Cmd> {
+        if let Some(KeyEvent(KeyCode::Char(c), m)) = evt.get(0) {
+            if m.contains(Modifiers::CTRL) || m.contains(Modifiers::ALT) || c.is_ascii_digit() {
+                None
+            } else {
+                Some(Cmd::Noop) // filter out invalid input
+            }
+        } else {
+            None
+        }
+    }
+}
+
+fn main() {
+    let mut rl = Editor::<()>::new();
+
+    rl.bind_sequence(
+        Event::Any,
+        EventHandler::Conditional(Box::new(FilteringEventHandler)),
+    );
+
+    loop {
+        let readline = rl.readline("> ");
+        match readline {
+            Ok(line) => {
+                println!("Num: {}", line);
+            }
+            Err(err) => {
+                println!("Error: {:?}", err);
+                break;
+            }
+        }
+    }
+}