1 files changed, 139 insertions, 0 deletions

diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
new file mode 100644
index 000000000..7bf06c7f7
--- /dev/null
+++ b/crates/ra_hir/src/lib.rs
@@ -0,0 +1,139 @@
+//! HIR (previsouly known as descriptors) provides a high-level OO acess to Rust
+//! code.
+//!
+//! The principal difference between HIR and syntax trees is that HIR is bound
+//! to a particular crate instance. That is, it has cfg flags and features
+//! applied. So, there relation between syntax and HIR is many-to-one.
+
+macro_rules! ctry {
+    ($expr:expr) => {
+        match $expr {
+            None => return Ok(None),
+            Some(it) => it,
+        }
+    };
+}
+
+pub(crate) mod db;
+mod query_definitions;
+mod function;
+mod module;
+mod path;
+mod arena;
+
+use std::ops::Index;
+
+use ra_syntax::{SyntaxNodeRef, SyntaxNode};
+use ra_db::{LocationIntener, SourceRootId, FileId, Cancelable};
+
+use crate::{
+    db::HirDatabase,
+    arena::{Arena, Id},
+};
+
+pub(crate) use self::{
+    path::{Path, PathKind},
+    module::{Module, ModuleId, Problem},
+    function::{Function, FnScopes},
+};
+
+pub use self::function::FnSignatureInfo;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub(crate) struct FnId(u32);
+ra_db::impl_numeric_id!(FnId);
+
+impl FnId {
+    pub(crate) fn from_loc(
+        db: &impl AsRef<LocationIntener<SourceItemId, FnId>>,
+        loc: &SourceItemId,
+    ) -> FnId {
+        db.as_ref().loc2id(loc)
+    }
+    pub(crate) fn loc(self, db: &impl AsRef<LocationIntener<SourceItemId, FnId>>) -> SourceItemId {
+        db.as_ref().id2loc(self)
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub(crate) struct DefId(u32);
+ra_db::impl_numeric_id!(DefId);
+
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub(crate) enum DefLoc {
+    Module {
+        id: ModuleId,
+        source_root: SourceRootId,
+    },
+    Item {
+        source_item_id: SourceItemId,
+    },
+}
+
+impl DefId {
+    pub(crate) fn loc(self, db: &impl AsRef<LocationIntener<DefLoc, DefId>>) -> DefLoc {
+        db.as_ref().id2loc(self)
+    }
+}
+
+impl DefLoc {
+    pub(crate) fn id(&self, db: &impl AsRef<LocationIntener<DefLoc, DefId>>) -> DefId {
+        db.as_ref().loc2id(&self)
+    }
+}
+
+pub(crate) enum Def {
+    Module(Module),
+    Item,
+}
+
+impl DefId {
+    pub(crate) fn resolve(self, db: &impl HirDatabase) -> Cancelable<Def> {
+        let loc = self.loc(db);
+        let res = match loc {
+            DefLoc::Module { id, source_root } => {
+                let descr = Module::new(db, source_root, id)?;
+                Def::Module(descr)
+            }
+            DefLoc::Item { .. } => Def::Item,
+        };
+        Ok(res)
+    }
+}
+
+/// Identifier of item within a specific file. This is stable over reparses, so
+/// it's OK to use it as a salsa key/value.
+pub(crate) type SourceFileItemId = Id<SyntaxNode>;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub(crate) struct SourceItemId {
+    file_id: FileId,
+    item_id: SourceFileItemId,
+}
+
+/// Maps item's `SyntaxNode`s to `SourceFileItemId` and back.
+#[derive(Debug, PartialEq, Eq, Default)]
+pub(crate) struct SourceFileItems {
+    arena: Arena<SyntaxNode>,
+}
+
+impl SourceFileItems {
+    fn alloc(&mut self, item: SyntaxNode) -> SourceFileItemId {
+        self.arena.alloc(item)
+    }
+    fn id_of(&self, item: SyntaxNodeRef) -> SourceFileItemId {
+        let (id, _item) = self
+            .arena
+            .iter()
+            .find(|(_id, i)| i.borrowed() == item)
+            .unwrap();
+        id
+    }
+}
+
+impl Index<SourceFileItemId> for SourceFileItems {
+    type Output = SyntaxNode;
+    fn index(&self, idx: SourceFileItemId) -> &SyntaxNode {
+        &self.arena[idx]
+    }
+}