1 files changed, 162 insertions, 0 deletions

diff --git a/crates/ra_hir_def/src/type_ref.rs b/crates/ra_hir_def/src/type_ref.rs
new file mode 100644
index 000000000..8af061116
--- /dev/null
+++ b/crates/ra_hir_def/src/type_ref.rs
@@ -0,0 +1,162 @@
+//! 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::{self, TypeAscriptionOwner, TypeBoundsOwner};
+
+use crate::path::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(Vec<TypeBound>),
+    DynTrait(Vec<TypeBound>),
+    Error,
+}
+
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+pub enum TypeBound {
+    Path(Path),
+    // also for<> bounds
+    // also Lifetimes
+    Error,
+}
+
+impl TypeRef {
+    /// Converts an `ast::TypeRef` to a `hir::TypeRef`.
+    pub fn from_ast(node: ast::TypeRef) -> Self {
+        match node {
+            ast::TypeRef::ParenType(inner) => TypeRef::from_ast_opt(inner.type_ref()),
+            ast::TypeRef::TupleType(inner) => {
+                TypeRef::Tuple(inner.fields().map(TypeRef::from_ast).collect())
+            }
+            ast::TypeRef::NeverType(..) => TypeRef::Never,
+            ast::TypeRef::PathType(inner) => {
+                // FIXME: Use `Path::from_src`
+                inner.path().and_then(Path::from_ast).map(TypeRef::Path).unwrap_or(TypeRef::Error)
+            }
+            ast::TypeRef::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)
+            }
+            ast::TypeRef::ArrayType(inner) => {
+                TypeRef::Array(Box::new(TypeRef::from_ast_opt(inner.type_ref())))
+            }
+            ast::TypeRef::SliceType(inner) => {
+                TypeRef::Slice(Box::new(TypeRef::from_ast_opt(inner.type_ref())))
+            }
+            ast::TypeRef::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)
+            }
+            ast::TypeRef::PlaceholderType(_inner) => TypeRef::Placeholder,
+            ast::TypeRef::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.ascribed_type()).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...
+            ast::TypeRef::ForType(inner) => TypeRef::from_ast_opt(inner.type_ref()),
+            ast::TypeRef::ImplTraitType(inner) => {
+                TypeRef::ImplTrait(type_bounds_from_ast(inner.type_bound_list()))
+            }
+            ast::TypeRef::DynTraitType(inner) => {
+                TypeRef::DynTrait(type_bounds_from_ast(inner.type_bound_list()))
+            }
+        }
+    }
+
+    pub fn from_ast_opt(node: Option<ast::TypeRef>) -> Self {
+        if let Some(node) = node {
+            TypeRef::from_ast(node)
+        } else {
+            TypeRef::Error
+        }
+    }
+
+    pub fn unit() -> TypeRef {
+        TypeRef::Tuple(Vec::new())
+    }
+}
+
+pub(crate) fn type_bounds_from_ast(type_bounds_opt: Option<ast::TypeBoundList>) -> Vec<TypeBound> {
+    if let Some(type_bounds) = type_bounds_opt {
+        type_bounds.bounds().map(TypeBound::from_ast).collect()
+    } else {
+        vec![]
+    }
+}
+
+impl TypeBound {
+    pub fn from_ast(node: ast::TypeBound) -> Self {
+        match node.kind() {
+            ast::TypeBoundKind::PathType(path_type) => {
+                let path = match path_type.path() {
+                    Some(p) => p,
+                    None => return TypeBound::Error,
+                };
+                // FIXME: Use `Path::from_src`
+                let path = match Path::from_ast(path) {
+                    Some(p) => p,
+                    None => return TypeBound::Error,
+                };
+                TypeBound::Path(path)
+            }
+            ast::TypeBoundKind::ForType(_) | ast::TypeBoundKind::Lifetime(_) => TypeBound::Error,
+        }
+    }
+
+    pub fn as_path(&self) -> Option<&Path> {
+        match self {
+            TypeBound::Path(p) => Some(p),
+            _ => None,
+        }
+    }
+}