7 files changed, 180 insertions, 84 deletions

diff --git a/crates/ra_hir/src/adt.rs b/crates/ra_hir/src/adt.rs
index 40a45b831..dae04d258 100644
--- a/crates/ra_hir/src/adt.rs
+++ b/crates/ra_hir/src/adt.rs
@@ -145,7 +145,7 @@ impl VariantData {
                     .map(|(i, fd)| {
                         Ok(StructField {
                             name: SmolStr::new(i.to_string()),
-                            ty: Ty::new_opt(db, &module, fd.type_ref())?,
+                            ty: Ty::from_ast_opt(db, &module, fd.type_ref())?,
                         })
                     })
                     .collect::<Cancelable<_>>()?;
@@ -160,7 +160,7 @@ impl VariantData {
                                 .name()
                                 .map(|n| n.text())
                                 .unwrap_or_else(|| SmolStr::new("[error]")),
-                            ty: Ty::new_opt(db, &module, fd.type_ref())?,
+                            ty: Ty::from_ast_opt(db, &module, fd.type_ref())?,
                         })
                     })
                     .collect::<Cancelable<_>>()?;
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 68fdbb7ea..f1cc0ccd0 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -26,6 +26,7 @@ mod krate;
 mod module;
 mod function;
 mod adt;
+mod type_ref;
 mod ty;
 
 use std::ops::Index;
diff --git a/crates/ra_hir/src/module.rs b/crates/ra_hir/src/module.rs
index e1a0e4b59..b9d36f01f 100644
--- a/crates/ra_hir/src/module.rs
+++ b/crates/ra_hir/src/module.rs
@@ -115,7 +115,7 @@ impl Module {
         Ok(res)
     }
 
-    pub fn resolve_path(&self, db: &impl HirDatabase, path: Path) -> Cancelable<PerNs<DefId>> {
+    pub fn resolve_path(&self, db: &impl HirDatabase, path: &Path) -> Cancelable<PerNs<DefId>> {
         let mut curr_per_ns = PerNs::types(
             match path.kind {
                 PathKind::Crate => self.crate_root(),
@@ -131,7 +131,7 @@ impl Module {
             .def_id(db),
         );
 
-        let segments = path.segments;
+        let segments = &path.segments;
         for name in segments.iter() {
             let curr = if let Some(r) = curr_per_ns.as_ref().take(Namespace::Types) {
                 r
diff --git a/crates/ra_hir/src/module/nameres.rs b/crates/ra_hir/src/module/nameres.rs
index 33c9d93c2..98cd225dd 100644
--- a/crates/ra_hir/src/module/nameres.rs
+++ b/crates/ra_hir/src/module/nameres.rs
@@ -451,7 +451,7 @@ where
                                 segments: import.path.segments[i + 1..].iter().cloned().collect(),
                                 kind: PathKind::Crate,
                             };
-                            let def_id = module.resolve_path(self.db, path)?;
+                            let def_id = module.resolve_path(self.db, &path)?;
                             if !def_id.is_none() {
                                 self.update(module_id, |items| {
                                     let res = Resolution {
diff --git a/crates/ra_hir/src/path.rs b/crates/ra_hir/src/path.rs
index e04d00900..0b260072c 100644
--- a/crates/ra_hir/src/path.rs
+++ b/crates/ra_hir/src/path.rs
@@ -1,12 +1,12 @@
 use ra_syntax::{SmolStr, ast, AstNode, TextRange};
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Path {
     pub kind: PathKind,
     pub segments: Vec<SmolStr>,
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum PathKind {
     Plain,
     Self_,
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index 54aa6715c..11b4caa23 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -19,38 +19,9 @@ use crate::{
     Def, DefId, FnScopes, Module, Function, Struct, Enum, Path,
     db::HirDatabase,
     adt::VariantData,
+    type_ref::{TypeRef, Mutability},
 };
 
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
-pub enum Mutability {
-    Shared,
-    Mut,
-}
-
-impl Mutability {
-    pub fn from_mutable(mutable: bool) -> Mutability {
-        if mutable {
-            Mutability::Mut
-        } else {
-            Mutability::Shared
-        }
-    }
-
-    pub fn as_keyword_for_ref(self) -> &'static str {
-        match self {
-            Mutability::Shared => "",
-            Mutability::Mut => "mut ",
-        }
-    }
-
-    pub fn as_keyword_for_ptr(self) -> &'static str {
-        match self {
-            Mutability::Shared => "const ",
-            Mutability::Mut => "mut ",
-        }
-    }
-}
-
 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub enum Ty {
     /// The primitive boolean type. Written as `bool`.
@@ -156,16 +127,58 @@ pub struct FnSig {
 }
 
 impl Ty {
-    pub(crate) fn new_from_ast_path(
+    pub(crate) fn from_hir(
         db: &impl HirDatabase,
         module: &Module,
-        path: ast::Path,
+        type_ref: &TypeRef,
+    ) -> Cancelable<Self> {
+        Ok(match type_ref {
+            TypeRef::Never => Ty::Never,
+            TypeRef::Tuple(inner) => {
+                let inner_tys = inner
+                    .iter()
+                    .map(|tr| Ty::from_hir(db, module, tr))
+                    .collect::<Cancelable<_>>()?;
+                Ty::Tuple(inner_tys)
+            }
+            TypeRef::Path(path) => Ty::from_hir_path(db, module, path)?,
+            TypeRef::RawPtr(inner, mutability) => {
+                let inner_ty = Ty::from_hir(db, module, inner)?;
+                Ty::RawPtr(Arc::new(inner_ty), *mutability)
+            }
+            TypeRef::Array(_inner) => Ty::Unknown, // TODO
+            TypeRef::Slice(inner) => {
+                let inner_ty = Ty::from_hir(db, module, inner)?;
+                Ty::Slice(Arc::new(inner_ty))
+            }
+            TypeRef::Reference(inner, mutability) => {
+                let inner_ty = Ty::from_hir(db, module, inner)?;
+                Ty::Ref(Arc::new(inner_ty), *mutability)
+            }
+            TypeRef::Placeholder => Ty::Unknown, // TODO
+            TypeRef::Fn(params) => {
+                let mut inner_tys = params
+                    .iter()
+                    .map(|tr| Ty::from_hir(db, module, tr))
+                    .collect::<Cancelable<Vec<_>>>()?;
+                let return_ty = inner_tys
+                    .pop()
+                    .expect("TypeRef::Fn should always have at least return type");
+                let sig = FnSig {
+                    input: inner_tys,
+                    output: return_ty,
+                };
+                Ty::FnPtr(Arc::new(sig))
+            }
+            TypeRef::Error => Ty::Unknown,
+        })
+    }
+
+    pub(crate) fn from_hir_path(
+        db: &impl HirDatabase,
+        module: &Module,
+        path: &Path,
     ) -> Cancelable<Self> {
-        let path = if let Some(p) = Path::from_ast(path) {
-            p
-        } else {
-            return Ok(Ty::Unknown);
-        };
         if path.is_ident() {
             let name = &path.segments[0];
             if let Some(int_ty) = primitive::IntTy::from_string(&name) {
@@ -187,50 +200,22 @@ impl Ty {
         Ok(ty)
     }
 
-    pub(crate) fn new_opt(
+    // TODO: These should not be necessary long-term, since everything will work on HIR
+    pub(crate) fn from_ast_opt(
         db: &impl HirDatabase,
         module: &Module,
         node: Option<ast::TypeRef>,
     ) -> Cancelable<Self> {
-        node.map(|n| Ty::new(db, module, n))
+        node.map(|n| Ty::from_ast(db, module, n))
             .unwrap_or(Ok(Ty::Unknown))
     }
 
-    pub(crate) fn new(
+    pub(crate) fn from_ast(
         db: &impl HirDatabase,
         module: &Module,
         node: ast::TypeRef,
     ) -> Cancelable<Self> {
-        use ra_syntax::ast::TypeRef::*;
-        Ok(match node {
-            ParenType(inner) => Ty::new_opt(db, module, inner.type_ref())?,
-            TupleType(_inner) => Ty::Unknown, // TODO
-            NeverType(..) => Ty::Never,
-            PathType(inner) => {
-                if let Some(path) = inner.path() {
-                    Ty::new_from_ast_path(db, module, path)?
-                } else {
-                    Ty::Unknown
-                }
-            }
-            PointerType(inner) => {
-                let inner_ty = Ty::new_opt(db, module, inner.type_ref())?;
-                let mutability = Mutability::from_mutable(inner.is_mut());
-                Ty::RawPtr(Arc::new(inner_ty), mutability)
-            }
-            ArrayType(_inner) => Ty::Unknown, // TODO
-            SliceType(_inner) => Ty::Unknown, // TODO
-            ReferenceType(inner) => {
-                let inner_ty = Ty::new_opt(db, module, inner.type_ref())?;
-                let mutability = Mutability::from_mutable(inner.is_mut());
-                Ty::Ref(Arc::new(inner_ty), mutability)
-            }
-            PlaceholderType(_inner) => Ty::Unknown, // TODO
-            FnPointerType(_inner) => Ty::Unknown,   // TODO
-            ForType(_inner) => Ty::Unknown,         // TODO
-            ImplTraitType(_inner) => Ty::Unknown,   // TODO
-            DynTraitType(_inner) => Ty::Unknown,    // TODO
-        })
+        Ty::from_hir(db, module, &TypeRef::from_ast(node))
     }
 
     pub fn unit() -> Self {
@@ -280,11 +265,11 @@ pub fn type_for_fn(db: &impl HirDatabase, f: Function) -> Cancelable<Ty> {
         .param_list()
         .map(|pl| {
             pl.params()
-                .map(|p| Ty::new_opt(db, &module, p.type_ref()))
+                .map(|p| Ty::from_ast_opt(db, &module, p.type_ref()))
                 .collect()
         })
         .unwrap_or_else(|| Ok(Vec::new()))?;
-    let output = Ty::new_opt(db, &module, node.ret_type().and_then(|rt| rt.type_ref()))?;
+    let output = Ty::from_ast_opt(db, &module, node.ret_type().and_then(|rt| rt.type_ref()))?;
     let sig = FnSig { input, output };
     Ok(Ty::FnPtr(Arc::new(sig)))
 }
@@ -390,7 +375,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         };
 
         // resolve in module
-        let resolved = ctry!(self.module.resolve_path(self.db, path)?.take_values());
+        let resolved = ctry!(self.module.resolve_path(self.db, &path)?.take_values());
         let ty = self.db.type_for_def(resolved)?;
         // TODO we will need to add type variables for type parameters etc. here
         Ok(Some(ty))
@@ -405,7 +390,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         } else {
             return Ok((Ty::Unknown, None));
         };
-        let def_id = if let Some(def_id) = self.module.resolve_path(self.db, path)?.take_types() {
+        let def_id = if let Some(def_id) = self.module.resolve_path(self.db, &path)?.take_types() {
             def_id
         } else {
             return Ok((Ty::Unknown, None));
@@ -575,7 +560,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             }
             ast::Expr::CastExpr(e) => {
                 let _inner_ty = self.infer_expr_opt(e.expr())?;
-                let cast_ty = Ty::new_opt(self.db, &self.module, e.type_ref())?;
+                let cast_ty = Ty::from_ast_opt(self.db, &self.module, e.type_ref())?;
                 // TODO do the coercion...
                 cast_ty
             }
@@ -620,7 +605,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         for stmt in node.statements() {
             match stmt {
                 ast::Stmt::LetStmt(stmt) => {
-                    let decl_ty = Ty::new_opt(self.db, &self.module, stmt.type_ref())?;
+                    let decl_ty = Ty::from_ast_opt(self.db, &self.module, stmt.type_ref())?;
                     let ty = if let Some(expr) = stmt.initializer() {
                         // TODO pass expectation
                         let expr_ty = self.infer_expr(expr)?;
@@ -665,7 +650,7 @@ pub fn infer(db: &impl HirDatabase, function: Function) -> Cancelable<InferenceR
                 continue;
             };
             if let Some(type_ref) = param.type_ref() {
-                let ty = Ty::new(db, &ctx.module, type_ref)?;
+                let ty = Ty::from_ast(db, &ctx.module, type_ref)?;
                 ctx.type_of.insert(LocalSyntaxPtr::new(pat.syntax()), ty);
             } else {
                 // TODO self param
diff --git a/crates/ra_hir/src/type_ref.rs b/crates/ra_hir/src/type_ref.rs
new file mode 100644
index 000000000..ae163313f
--- /dev/null
+++ b/crates/ra_hir/src/type_ref.rs
@@ -0,0 +1,110 @@
+//! HIR for references to types. Paths in these are not yet resolved. They can
+//! be directly created from an ast::TypeRef, without further queries.
+
+use ra_syntax::ast;
+
+use crate::Path;
+
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+pub enum Mutability {
+    Shared,
+    Mut,
+}
+
+impl Mutability {
+    pub fn from_mutable(mutable: bool) -> Mutability {
+        if mutable {
+            Mutability::Mut
+        } else {
+            Mutability::Shared
+        }
+    }
+
+    pub fn as_keyword_for_ref(self) -> &'static str {
+        match self {
+            Mutability::Shared => "",
+            Mutability::Mut => "mut ",
+        }
+    }
+
+    pub fn as_keyword_for_ptr(self) -> &'static str {
+        match self {
+            Mutability::Shared => "const ",
+            Mutability::Mut => "mut ",
+        }
+    }
+}
+
+/// Compare ty::Ty
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+pub enum TypeRef {
+    Never,
+    Placeholder,
+    Tuple(Vec<TypeRef>),
+    Path(Path),
+    RawPtr(Box<TypeRef>, Mutability),
+    Reference(Box<TypeRef>, Mutability),
+    Array(Box<TypeRef> /*, Expr*/),
+    Slice(Box<TypeRef>),
+    /// A fn pointer. Last element of the vector is the return type.
+    Fn(Vec<TypeRef>),
+    // For
+    // ImplTrait,
+    // DynTrait,
+    Error,
+}
+
+impl TypeRef {
+    /// Converts an `ast::TypeRef` to a `hir::TypeRef`.
+    pub(crate) fn from_ast(node: ast::TypeRef) -> Self {
+        use ra_syntax::ast::TypeRef::*;
+        match node {
+            ParenType(inner) => TypeRef::from_ast_opt(inner.type_ref()),
+            TupleType(inner) => TypeRef::Tuple(inner.fields().map(TypeRef::from_ast).collect()),
+            NeverType(..) => TypeRef::Never,
+            PathType(inner) => inner
+                .path()
+                .and_then(Path::from_ast)
+                .map(TypeRef::Path)
+                .unwrap_or(TypeRef::Error),
+            PointerType(inner) => {
+                let inner_ty = TypeRef::from_ast_opt(inner.type_ref());
+                let mutability = Mutability::from_mutable(inner.is_mut());
+                TypeRef::RawPtr(Box::new(inner_ty), mutability)
+            }
+            ArrayType(inner) => TypeRef::Array(Box::new(TypeRef::from_ast_opt(inner.type_ref()))),
+            SliceType(inner) => TypeRef::Slice(Box::new(TypeRef::from_ast_opt(inner.type_ref()))),
+            ReferenceType(inner) => {
+                let inner_ty = TypeRef::from_ast_opt(inner.type_ref());
+                let mutability = Mutability::from_mutable(inner.is_mut());
+                TypeRef::Reference(Box::new(inner_ty), mutability)
+            }
+            PlaceholderType(_inner) => TypeRef::Placeholder,
+            FnPointerType(inner) => {
+                let ret_ty = TypeRef::from_ast_opt(inner.ret_type().and_then(|rt| rt.type_ref()));
+                let mut params = if let Some(pl) = inner.param_list() {
+                    pl.params()
+                        .map(|p| p.type_ref())
+                        .map(TypeRef::from_ast_opt)
+                        .collect()
+                } else {
+                    Vec::new()
+                };
+                params.push(ret_ty);
+                TypeRef::Fn(params)
+            }
+            // for types are close enough for our purposes to the inner type for now...
+            ForType(inner) => TypeRef::from_ast_opt(inner.type_ref()),
+            ImplTraitType(_inner) => TypeRef::Error,
+            DynTraitType(_inner) => TypeRef::Error,
+        }
+    }
+
+    fn from_ast_opt(node: Option<ast::TypeRef>) -> Self {
+        if let Some(node) = node {
+            TypeRef::from_ast(node)
+        } else {
+            TypeRef::Error
+        }
+    }
+}