working f and t bindings

crates/gpui/src/keymap_matcher/binding.rs

@@ -0,0 +1,104 @@
+use anyhow::Result;
+use smallvec::SmallVec;
+
+use crate::Action;
+
+use super::{KeymapContext, KeymapContextPredicate, Keystroke};
+
+pub struct Binding {
+    action: Box<dyn Action>,
+    keystrokes: Option<SmallVec<[Keystroke; 2]>>,
+    context_predicate: Option<KeymapContextPredicate>,
+}
+
+impl Binding {
+    pub fn new<A: Action>(keystrokes: &str, action: A, context: Option<&str>) -> Self {
+        Self::load(keystrokes, Box::new(action), context).unwrap()
+    }
+
+    pub fn load(keystrokes: &str, action: Box<dyn Action>, context: Option<&str>) -> Result<Self> {
+        let context = if let Some(context) = context {
+            Some(KeymapContextPredicate::parse(context)?)
+        } else {
+            None
+        };
+
+        let keystrokes = if keystrokes == "*" {
+            None // Catch all context
+        } else {
+            Some(
+                keystrokes
+                    .split_whitespace()
+                    .map(Keystroke::parse)
+                    .collect::<Result<_>>()?,
+            )
+        };
+
+        Ok(Self {
+            keystrokes,
+            action,
+            context_predicate: context,
+        })
+    }
+
+    fn match_context(&self, context: &KeymapContext) -> bool {
+        self.context_predicate
+            .as_ref()
+            .map(|predicate| predicate.eval(context))
+            .unwrap_or(true)
+    }
+
+    pub fn match_keys_and_context(
+        &self,
+        pending_keystrokes: &Vec<Keystroke>,
+        context: &KeymapContext,
+    ) -> BindingMatchResult {
+        if self
+            .keystrokes
+            .as_ref()
+            .map(|keystrokes| keystrokes.starts_with(&pending_keystrokes))
+            .unwrap_or(true)
+            && self.match_context(context)
+        {
+            // If the binding is completed, push it onto the matches list
+            if self
+                .keystrokes
+                .as_ref()
+                .map(|keystrokes| keystrokes.len() == pending_keystrokes.len())
+                .unwrap_or(true)
+            {
+                BindingMatchResult::Complete(self.action.boxed_clone())
+            } else {
+                BindingMatchResult::Partial
+            }
+        } else {
+            BindingMatchResult::Fail
+        }
+    }
+
+    pub fn keystrokes_for_action(
+        &self,
+        action: &dyn Action,
+        context: &KeymapContext,
+    ) -> Option<SmallVec<[Keystroke; 2]>> {
+        if self.action.eq(action) && self.match_context(context) {
+            self.keystrokes.clone()
+        } else {
+            None
+        }
+    }
+
+    pub fn keystrokes(&self) -> Option<&[Keystroke]> {
+        self.keystrokes.as_deref()
+    }
+
+    pub fn action(&self) -> &dyn Action {
+        self.action.as_ref()
+    }
+}
+
+pub enum BindingMatchResult {
+    Complete(Box<dyn Action>),
+    Partial,
+    Fail,
+}

crates/gpui/src/keymap_matcher/keymap.rs

@@ -0,0 +1,61 @@
+use smallvec::SmallVec;
+use std::{
+    any::{Any, TypeId},
+    collections::HashMap,
+};
+
+use super::Binding;
+
+#[derive(Default)]
+pub struct Keymap {
+    bindings: Vec<Binding>,
+    binding_indices_by_action_type: HashMap<TypeId, SmallVec<[usize; 3]>>,
+}
+
+impl Keymap {
+    pub fn new(bindings: Vec<Binding>) -> Self {
+        let mut binding_indices_by_action_type = HashMap::new();
+        for (ix, binding) in bindings.iter().enumerate() {
+            binding_indices_by_action_type
+                .entry(binding.action().type_id())
+                .or_insert_with(SmallVec::new)
+                .push(ix);
+        }
+
+        Self {
+            binding_indices_by_action_type,
+            bindings,
+        }
+    }
+
+    pub(crate) fn bindings_for_action_type(
+        &self,
+        action_type: TypeId,
+    ) -> impl Iterator<Item = &'_ Binding> {
+        self.binding_indices_by_action_type
+            .get(&action_type)
+            .map(SmallVec::as_slice)
+            .unwrap_or(&[])
+            .iter()
+            .map(|ix| &self.bindings[*ix])
+    }
+
+    pub(crate) fn add_bindings<T: IntoIterator<Item = Binding>>(&mut self, bindings: T) {
+        for binding in bindings {
+            self.binding_indices_by_action_type
+                .entry(binding.action().type_id())
+                .or_default()
+                .push(self.bindings.len());
+            self.bindings.push(binding);
+        }
+    }
+
+    pub(crate) fn clear(&mut self) {
+        self.bindings.clear();
+        self.binding_indices_by_action_type.clear();
+    }
+
+    pub fn bindings(&self) -> &Vec<Binding> {
+        &self.bindings
+    }
+}

crates/gpui/src/keymap_matcher/keymap_context.rs

@@ -0,0 +1,123 @@
+use anyhow::anyhow;
+
+use collections::{HashMap, HashSet};
+use tree_sitter::{Language, Node, Parser};
+
+extern "C" {
+    fn tree_sitter_context_predicate() -> Language;
+}
+
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+pub struct KeymapContext {
+    pub set: HashSet<String>,
+    pub map: HashMap<String, String>,
+}
+
+impl KeymapContext {
+    pub fn extend(&mut self, other: &Self) {
+        for v in &other.set {
+            self.set.insert(v.clone());
+        }
+        for (k, v) in &other.map {
+            self.map.insert(k.clone(), v.clone());
+        }
+    }
+}
+
+#[derive(Debug, Eq, PartialEq)]
+pub enum KeymapContextPredicate {
+    Identifier(String),
+    Equal(String, String),
+    NotEqual(String, String),
+    Not(Box<KeymapContextPredicate>),
+    And(Box<KeymapContextPredicate>, Box<KeymapContextPredicate>),
+    Or(Box<KeymapContextPredicate>, Box<KeymapContextPredicate>),
+}
+
+impl KeymapContextPredicate {
+    pub fn parse(source: &str) -> anyhow::Result<Self> {
+        let mut parser = Parser::new();
+        let language = unsafe { tree_sitter_context_predicate() };
+        parser.set_language(language).unwrap();
+        let source = source.as_bytes();
+        let tree = parser.parse(source, None).unwrap();
+        Self::from_node(tree.root_node(), source)
+    }
+
+    fn from_node(node: Node, source: &[u8]) -> anyhow::Result<Self> {
+        let parse_error = "error parsing context predicate";
+        let kind = node.kind();
+
+        match kind {
+            "source" => Self::from_node(node.child(0).ok_or_else(|| anyhow!(parse_error))?, source),
+            "identifier" => Ok(Self::Identifier(node.utf8_text(source)?.into())),
+            "not" => {
+                let child = Self::from_node(
+                    node.child_by_field_name("expression")
+                        .ok_or_else(|| anyhow!(parse_error))?,
+                    source,
+                )?;
+                Ok(Self::Not(Box::new(child)))
+            }
+            "and" | "or" => {
+                let left = Box::new(Self::from_node(
+                    node.child_by_field_name("left")
+                        .ok_or_else(|| anyhow!(parse_error))?,
+                    source,
+                )?);
+                let right = Box::new(Self::from_node(
+                    node.child_by_field_name("right")
+                        .ok_or_else(|| anyhow!(parse_error))?,
+                    source,
+                )?);
+                if kind == "and" {
+                    Ok(Self::And(left, right))
+                } else {
+                    Ok(Self::Or(left, right))
+                }
+            }
+            "equal" | "not_equal" => {
+                let left = node
+                    .child_by_field_name("left")
+                    .ok_or_else(|| anyhow!(parse_error))?
+                    .utf8_text(source)?
+                    .into();
+                let right = node
+                    .child_by_field_name("right")
+                    .ok_or_else(|| anyhow!(parse_error))?
+                    .utf8_text(source)?
+                    .into();
+                if kind == "equal" {
+                    Ok(Self::Equal(left, right))
+                } else {
+                    Ok(Self::NotEqual(left, right))
+                }
+            }
+            "parenthesized" => Self::from_node(
+                node.child_by_field_name("expression")
+                    .ok_or_else(|| anyhow!(parse_error))?,
+                source,
+            ),
+            _ => Err(anyhow!(parse_error)),
+        }
+    }
+
+    pub fn eval(&self, context: &KeymapContext) -> bool {
+        match self {
+            Self::Identifier(name) => context.set.contains(name.as_str()),
+            Self::Equal(left, right) => context
+                .map
+                .get(left)
+                .map(|value| value == right)
+                .unwrap_or(false),
+            Self::NotEqual(left, right) => context
+                .map
+                .get(left)
+                .map(|value| value != right)
+                .unwrap_or(true),
+            Self::Not(pred) => !pred.eval(context),
+            Self::And(left, right) => left.eval(context) && right.eval(context),
+            Self::Or(left, right) => left.eval(context) || right.eval(context),
+        }
+    }
+}

crates/gpui/src/keymap_matcher/keystroke.rs

@@ -0,0 +1,97 @@
+use std::fmt::Write;
+
+use anyhow::anyhow;
+use serde::Deserialize;
+
+#[derive(Clone, Debug, Eq, PartialEq, Default, Deserialize)]
+pub struct Keystroke {
+    pub ctrl: bool,
+    pub alt: bool,
+    pub shift: bool,
+    pub cmd: bool,
+    pub function: bool,
+    pub key: String,
+}
+
+impl Keystroke {
+    pub fn parse(source: &str) -> anyhow::Result<Self> {
+        let mut ctrl = false;
+        let mut alt = false;
+        let mut shift = false;
+        let mut cmd = false;
+        let mut function = false;
+        let mut key = None;
+
+        let mut components = source.split('-').peekable();
+        while let Some(component) = components.next() {
+            match component {
+                "ctrl" => ctrl = true,
+                "alt" => alt = true,
+                "shift" => shift = true,
+                "cmd" => cmd = true,
+                "fn" => function = true,
+                _ => {
+                    if let Some(component) = components.peek() {
+                        if component.is_empty() && source.ends_with('-') {
+                            key = Some(String::from("-"));
+                            break;
+                        } else {
+                            return Err(anyhow!("Invalid keystroke `{}`", source));
+                        }
+                    } else {
+                        key = Some(String::from(component));
+                    }
+                }
+            }
+        }
+
+        let key = key.ok_or_else(|| anyhow!("Invalid keystroke `{}`", source))?;
+
+        Ok(Keystroke {
+            ctrl,
+            alt,
+            shift,
+            cmd,
+            function,
+            key,
+        })
+    }
+
+    pub fn modified(&self) -> bool {
+        self.ctrl || self.alt || self.shift || self.cmd
+    }
+}
+
+impl std::fmt::Display for Keystroke {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if self.ctrl {
+            f.write_char('^')?;
+        }
+        if self.alt {
+            f.write_char('⎇')?;
+        }
+        if self.cmd {
+            f.write_char('⌘')?;
+        }
+        if self.shift {
+            f.write_char('⇧')?;
+        }
+        let key = match self.key.as_str() {
+            "backspace" => '⌫',
+            "up" => '↑',
+            "down" => '↓',
+            "left" => '←',
+            "right" => '→',
+            "tab" => '⇥',
+            "escape" => '⎋',
+            key => {
+                if key.len() == 1 {
+                    key.chars().next().unwrap().to_ascii_uppercase()
+                } else {
+                    return f.write_str(key);
+                }
+            }
+        };
+        f.write_char(key)
+    }
+}