Implement initial query engine

crates/building/Cargo.toml

@@ -6,8 +6,13 @@ edition = "2021"
 [dependencies]
 dashmap = "6.1.0"
 id = { version = "0.1.0", path = "../id" }
+indexing = { version = "0.1.0", path = "../indexing" }
 indexmap = "2.7.1"
+lexing = { version = "0.1.0", path = "../lexing" }
 parking_lot = "0.12.3"
+parsing = { version = "0.1.0", path = "../parsing" }
 petgraph = "0.7.1"
 rayon = "1.10.0"
+rowan = "0.16.1"
 rustc-hash = "2.1.0"
+syntax = { version = "0.1.0", path = "../syntax" }

crates/building/src/base.rs

@@ -1,5 +1,207 @@
+use std::{mem, sync::Arc};
+
+use indexing::IndexingResult;
+use rowan::ast::AstNode;
+use rustc_hash::{FxHashMap, FxHashSet};
+use syntax::cst;
+
+use crate::files::FileId;
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum QueryKey {
-    Index(usize),
-    Resolve(usize),
+    Content(FileId),
+    Parse(FileId),
+    Index(FileId),
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct Trace {
+    built: usize,
+    changed: usize,
+    dependencies: Arc<[QueryKey]>,
+}
+
+impl Trace {
+    pub fn create_input(revision: usize) -> Trace {
+        Trace { built: revision, changed: revision, dependencies: [].into() }
+    }
+
+    pub fn create_fresh(revision: usize, dependencies: Arc<[QueryKey]>) -> Trace {
+        Trace { built: revision, changed: revision, dependencies }
+    }
+}
+
+#[derive(Default)]
+pub struct Runtime {
+    revision: usize,
+    traces: FxHashMap<QueryKey, Trace>,
+
+    content: FxHashMap<FileId, Arc<str>>,
+    parse: FxHashMap<FileId, cst::Module>,
+    index: FxHashMap<FileId, Arc<IndexingResult>>,
+
+    parent: Option<QueryKey>,
+    dependencies: FxHashMap<QueryKey, FxHashSet<QueryKey>>,
+}
+
+impl Runtime {
+    pub fn compute<T>(&mut self, k: QueryKey, compute: impl Fn(&mut Runtime) -> T) -> T {
+        let parent = mem::replace(&mut self.parent, Some(k));
+        let result = compute(self);
+
+        self.revision += 1;
+        let revision = self.revision;
+
+        let dependencies = self
+            .dependencies
+            .get(&k)
+            .map(|dependencies| dependencies.iter().copied())
+            .unwrap_or_default()
+            .collect();
+
+        let v = Trace::create_fresh(revision, dependencies);
+        self.traces.insert(k, v);
+
+        self.parent = parent;
+        result
+    }
+
+    pub fn query<T: Clone>(
+        &mut self,
+        k: QueryKey,
+        compute: impl Fn(&mut Runtime) -> T,
+        get_storage: impl Fn(&mut Runtime) -> Option<(T, &mut Trace)>,
+        set_storage: impl Fn(&mut Runtime, T),
+    ) -> T {
+        if let Some(parent) = self.parent {
+            self.dependencies.entry(parent).or_default().insert(k);
+        }
+
+        let revision = self.revision;
+        if let Some((value, trace)) = get_storage(self) {
+            if trace.built == revision {
+                value
+            } else {
+                let built = trace.built;
+                let dependencies = Arc::clone(&trace.dependencies);
+
+                let mut latest = 0;
+                for dependency in dependencies.iter() {
+                    match dependency {
+                        QueryKey::Content(_) => (),
+                        QueryKey::Parse(id) => {
+                            self.parse(*id);
+                        }
+                        QueryKey::Index(_) => (),
+                    }
+                    if let Some(dependency) = self.traces.get(dependency) {
+                        latest = latest.max(dependency.changed);
+                    }
+                }
+
+                if built >= latest {
+                    if let Some(trace) = self.traces.get_mut(&k) {
+                        trace.built = revision;
+                    }
+                    value
+                } else {
+                    let fresh = self.compute(k, compute);
+                    set_storage(self, T::clone(&fresh));
+                    fresh
+                }
+            }
+        } else {
+            let fresh = self.compute(k, compute);
+            set_storage(self, T::clone(&fresh));
+            fresh
+        }
+    }
+
+    pub fn set_content(&mut self, id: FileId, content: Arc<str>) {
+        self.revision += 1;
+        let revision = self.revision;
+
+        self.content.insert(id, content);
+
+        let k = QueryKey::Content(id);
+        let v = Trace::create_input(revision);
+        self.traces.insert(k, v);
+    }
+
+    pub fn content(&mut self, id: FileId) -> Arc<str> {
+        let k = QueryKey::Content(id);
+        if let Some(parent) = self.parent {
+            self.dependencies.entry(parent).or_default().insert(k);
+        }
+        let v = self.content.get(&id).expect("invalid violated: invalid query key");
+        Arc::clone(v)
+    }
+
+    pub fn parse(&mut self, id: FileId) -> cst::Module {
+        let k = QueryKey::Parse(id);
+        self.query(
+            k,
+            |this| {
+                let content = this.content(id);
+
+                let lexed = lexing::lex(&content);
+                let tokens = lexing::layout(&lexed);
+
+                let (node, _) = parsing::parse(&lexed, &tokens);
+                cst::Module::cast(node).expect("invariant violated: cannot cast parse result")
+            },
+            |this| {
+                let value = this.parse.get(&id).cloned()?;
+                let trace = this.traces.get_mut(&k)?;
+                Some((value, trace))
+            },
+            |this, value| {
+                this.parse.insert(id, value);
+            },
+        )
+    }
+
+    pub fn index(&mut self, id: FileId) -> Arc<IndexingResult> {
+        let k = QueryKey::Index(id);
+        self.query(
+            k,
+            |this| {
+                let module = this.parse(id);
+                let (result, _) = indexing::index(&module);
+                Arc::new(result)
+            },
+            |this| {
+                let value = this.index.get(&id).cloned()?;
+                let trace = this.traces.get_mut(&k)?;
+                Some((value, trace))
+            },
+            |this, value| {
+                this.index.insert(id, value);
+            },
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::files::Files;
+
+    use super::Runtime;
+
+    #[test]
+    fn test_basic() {
+        let mut runtime = Runtime::default();
+        let mut files = Files::default();
+
+        let id = files.insert("./src/Main.purs", "module Main where\n\nlife = 42");
+        let content = files.content(id);
+
+        runtime.set_content(id, content);
+        dbg!(runtime.index(id));
+        dbg!(runtime.index(id));
+
+        runtime.set_content(id, "module Main where\n\n\n\nlife   =   42".into());
+        dbg!(runtime.index(id));
+        dbg!(runtime.index(id));
+    }
 }