use std::rc::Rc; use collections::HashMap; use crate::{Action, InvalidKeystrokeError, KeyBindingContextPredicate, Keystroke};use smallvec::SmallVec; /// A keybinding and its associated metadata, from the keymap.pub struct KeyBinding {    pub(crate) action: Box<dyn Action>,    pub(crate) keystrokes: SmallVec<[Keystroke; 2]>,    pub(crate) context_predicate: Option<Rc<KeyBindingContextPredicate>>,    pub(crate) meta: Option<KeyBindingMetaIndex>,} impl Clone for KeyBinding {    fn clone(&self) -> Self {        KeyBinding {            action: self.action.boxed_clone(),            keystrokes: self.keystrokes.clone(),            context_predicate: self.context_predicate.clone(),            meta: self.meta,        }    }} impl KeyBinding {    /// Construct a new keybinding from the given data. Panics on parse error.    pub fn new<A: Action>(keystrokes: &str, action: A, context: Option<&str>) -> Self {        let context_predicate = if let Some(context) = context {            Some(KeyBindingContextPredicate::parse(context).unwrap().into())        } else {            None        };        Self::load(keystrokes, Box::new(action), context_predicate, None).unwrap()    }     /// Load a keybinding from the given raw data.    pub fn load(        keystrokes: &str,        action: Box<dyn Action>,        context_predicate: Option<Rc<KeyBindingContextPredicate>>,        key_equivalents: Option<&HashMap<char, char>>,    ) -> std::result::Result<Self, InvalidKeystrokeError> {        let mut keystrokes: SmallVec<[Keystroke; 2]> = keystrokes            .split_whitespace()            .map(Keystroke::parse)            .collect::<std::result::Result<_, _>>()?;         if let Some(equivalents) = key_equivalents {            for keystroke in keystrokes.iter_mut() {                if keystroke.key.chars().count() == 1 {                    if let Some(key) = equivalents.get(&keystroke.key.chars().next().unwrap()) {                        keystroke.key = key.to_string();                    }                }            }        }         Ok(Self {            keystrokes,            action,            context_predicate,            meta: None,        })    }     /// Set the metadata for this binding.    pub fn with_meta(mut self, meta: KeyBindingMetaIndex) -> Self {        self.meta = Some(meta);        self    }     /// Set the metadata for this binding.    pub fn set_meta(&mut self, meta: KeyBindingMetaIndex) {        self.meta = Some(meta);    }     /// Check if the given keystrokes match this binding.    pub fn match_keystrokes(&self, typed: &[Keystroke]) -> Option<bool> {        if self.keystrokes.len() < typed.len() {            return None;        }         for (target, typed) in self.keystrokes.iter().zip(typed.iter()) {            if !typed.should_match(target) {                return None;            }        }         Some(self.keystrokes.len() > typed.len())    }     /// Get the keystrokes associated with this binding    pub fn keystrokes(&self) -> &[Keystroke] {        self.keystrokes.as_slice()    }     /// Get the action associated with this binding    pub fn action(&self) -> &dyn Action {        self.action.as_ref()    }     /// Get the predicate used to match this binding    pub fn predicate(&self) -> Option<Rc<KeyBindingContextPredicate>> {        self.context_predicate.as_ref().map(|rc| rc.clone())    }     /// Get the metadata for this binding    pub fn meta(&self) -> Option<KeyBindingMetaIndex> {        self.meta    }} impl std::fmt::Debug for KeyBinding {    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {        f.debug_struct("KeyBinding")            .field("keystrokes", &self.keystrokes)            .field("context_predicate", &self.context_predicate)            .field("action", &self.action.name())            .finish()    }} /// A unique identifier for retrieval of metadata associated with a key binding./// Intended to be used as an index or key into a user-defined store of metadata/// associated with the binding, such as the source of the binding.#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]pub struct KeyBindingMetaIndex(pub u32);