Add fuzzy completions example

examples/fuzzy_completions.rs

@@ -0,0 +1,135 @@
+// Modifies the completions example to demonstrate highlighting of fuzzy completions
+// cargo run --example fuzzy_completions
+
+use reedline::{
+    default_emacs_keybindings, ColumnarMenu, Completer, DefaultPrompt, EditCommand, Emacs, KeyCode,
+    KeyModifiers, Keybindings, MenuBuilder, Reedline, ReedlineEvent, ReedlineMenu, Signal, Span,
+    Suggestion,
+};
+use std::io;
+
+struct HomegrownFuzzyCompleter(Vec<String>);
+
+impl Completer for HomegrownFuzzyCompleter {
+    fn complete(&mut self, line: &str, pos: usize) -> Vec<reedline::Suggestion> {
+        // Grandma's fuzzy matching recipe. She swears it's better than that crates.io-bought stuff
+        self.0
+            .iter()
+            .filter_map(|command_str| {
+                let command = command_str.chars().collect::<Vec<_>>();
+                let mut start = 0;
+                let mut match_indices = Vec::new();
+                for l in line.chars() {
+                    if start == command.len() {
+                        break;
+                    }
+                    let mut i = start;
+                    while i < command.len() && l != command[i] {
+                        i += 1;
+                    }
+                    if i < command.len() {
+                        match_indices.push(i);
+                        start = i + 1;
+                    }
+                }
+                if match_indices.is_empty() || match_indices.len() * 2 < pos {
+                    None
+                } else {
+                    Some(Suggestion {
+                        value: command_str.to_string(),
+                        description: None,
+                        style: None,
+                        extra: None,
+                        span: Span::new(pos - line.len(), pos),
+                        append_whitespace: false,
+                        match_indices: Some(match_indices),
+                    })
+                }
+            })
+            .collect()
+    }
+}
+
+fn add_menu_keybindings(keybindings: &mut Keybindings) {
+    keybindings.add_binding(
+        KeyModifiers::NONE,
+        KeyCode::Tab,
+        ReedlineEvent::UntilFound(vec![
+            ReedlineEvent::Menu("completion_menu".to_string()),
+            ReedlineEvent::MenuNext,
+        ]),
+    );
+    keybindings.add_binding(
+        KeyModifiers::ALT,
+        KeyCode::Enter,
+        ReedlineEvent::Edit(vec![EditCommand::InsertNewline]),
+    );
+}
+
+fn main() -> io::Result<()> {
+    // Number of columns
+    let columns: u16 = 4;
+    // Column width
+    let col_width: Option<usize> = None;
+    // Column padding
+    let col_padding: usize = 2;
+
+    let commands = vec![
+        "test".into(),
+        "clear".into(),
+        "exit".into(),
+        "history 1".into(),
+        "history 2".into(),
+        "logout".into(),
+        "login".into(),
+        "hello world".into(),
+        "hello world reedline".into(),
+        "hello world something".into(),
+        "hello world another".into(),
+        "hello world 1".into(),
+        "hello world 2".into(),
+        "hello another very large option for hello word that will force one column".into(),
+        "this is the reedline crate".into(),
+        "abaaabas".into(),
+        "abaaacas".into(),
+        "ababac".into(),
+        "abacaxyc".into(),
+        "abadarabc".into(),
+    ];
+
+    let completer = Box::new(HomegrownFuzzyCompleter(commands));
+
+    // Use the interactive menu to select options from the completer
+    let columnar_menu = ColumnarMenu::default()
+        .with_name("completion_menu")
+        .with_columns(columns)
+        .with_column_width(col_width)
+        .with_column_padding(col_padding);
+
+    let completion_menu = Box::new(columnar_menu);
+
+    let mut keybindings = default_emacs_keybindings();
+    add_menu_keybindings(&mut keybindings);
+
+    let edit_mode = Box::new(Emacs::new(keybindings));
+
+    let mut line_editor = Reedline::create()
+        .with_completer(completer)
+        .with_menu(ReedlineMenu::EngineCompleter(completion_menu))
+        .with_edit_mode(edit_mode);
+
+    let prompt = DefaultPrompt::default();
+
+    loop {
+        let sig = line_editor.read_line(&prompt)?;
+        match sig {
+            Signal::Success(buffer) => {
+                println!("We processed: {buffer}");
+            }
+            Signal::CtrlD | Signal::CtrlC => {
+                println!("\nAborted!");
+                break Ok(());
+            }
+        }
+    }
+}