Merge #370

370: Self params & type r=matklad a=flodiebold

This implements type inference for `self`, so field completion for methods taking `self` works now.

 - rename `IMPL_ITEM` to `IMPL_BLOCK` -- rustc calls the methods etc. inside an impl `ImplItem`s, and the impl itself doesn't define an item, so I thought this name was clearer.
 - add HIR for impl blocks -- we collect all impls in a crate at once, so we can go from methods to containing impls, and since we will later also need to find all impls for a certain type (which may be anywhere in the crate, I think?). We could be more lazy here, but I don't know if it's worth the complexity.
 - resolve `self` and `Self` during type inference
 - refactor a bit in ty.rs as well

Co-authored-by: Florian Diebold <[email protected]>

5 files changed, 126 insertions, 9 deletions

diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index 7f986d322..2a3bd27e2 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -482,6 +482,37 @@ impl<'a> PrefixExpr<'a> {
     }
 }
 
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub enum SelfParamFlavor {
+    /// self
+    Owned,
+    /// &self
+    Ref,
+    /// &mut self
+    MutRef,
+}
+
+impl<'a> SelfParam<'a> {
+    pub fn flavor(&self) -> SelfParamFlavor {
+        let borrowed = self.syntax().children().any(|n| n.kind() == AMP);
+        if borrowed {
+            // check for a `mut` coming after the & -- `mut &self` != `&mut self`
+            if self
+                .syntax()
+                .children()
+                .skip_while(|n| n.kind() != AMP)
+                .any(|n| n.kind() == MUT_KW)
+            {
+                SelfParamFlavor::MutRef
+            } else {
+                SelfParamFlavor::Ref
+            }
+        } else {
+            SelfParamFlavor::Owned
+        }
+    }
+}
+
 #[test]
 fn test_doc_comment_of_items() {
     let file = SourceFileNode::parse(
diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index c1c63f555..7df6a9c46 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -1442,7 +1442,39 @@ impl<R: TreeRoot<RaTypes>> ImplBlockNode<R> {
 }
 
 
-impl<'a> ImplBlock<'a> {}
+impl<'a> ImplBlock<'a> {
+    pub fn item_list(self) -> Option<ItemList<'a>> {
+        super::child_opt(self)
+    }
+}
+
+// ImplItem
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ImplItem<'a> {
+    FnDef(FnDef<'a>),
+    TypeDef(TypeDef<'a>),
+    ConstDef(ConstDef<'a>),
+}
+
+impl<'a> AstNode<'a> for ImplItem<'a> {
+    fn cast(syntax: SyntaxNodeRef<'a>) -> Option<Self> {
+        match syntax.kind() {
+            FN_DEF => Some(ImplItem::FnDef(FnDef { syntax })),
+            TYPE_DEF => Some(ImplItem::TypeDef(TypeDef { syntax })),
+            CONST_DEF => Some(ImplItem::ConstDef(ConstDef { syntax })),
+            _ => None,
+        }
+    }
+    fn syntax(self) -> SyntaxNodeRef<'a> {
+        match self {
+            ImplItem::FnDef(inner) => inner.syntax(),
+            ImplItem::TypeDef(inner) => inner.syntax(),
+            ImplItem::ConstDef(inner) => inner.syntax(),
+        }
+    }
+}
+
+impl<'a> ImplItem<'a> {}
 
 // ImplTraitType
 #[derive(Debug, Clone, Copy,)]
@@ -1555,7 +1587,11 @@ impl<R: TreeRoot<RaTypes>> ItemListNode<R> {
 
 impl<'a> ast::FnDefOwner<'a> for ItemList<'a> {}
 impl<'a> ast::ModuleItemOwner<'a> for ItemList<'a> {}
-impl<'a> ItemList<'a> {}
+impl<'a> ItemList<'a> {
+    pub fn impl_items(self) -> impl Iterator<Item = ImplItem<'a>> + 'a {
+        super::children(self)
+    }
+}
 
 // Label
 #[derive(Debug, Clone, Copy,)]
@@ -3452,6 +3488,43 @@ impl<'a> ReturnExpr<'a> {
     }
 }
 
+// SelfKw
+#[derive(Debug, Clone, Copy,)]
+pub struct SelfKwNode<R: TreeRoot<RaTypes> = OwnedRoot> {
+    pub(crate) syntax: SyntaxNode<R>,
+}
+pub type SelfKw<'a> = SelfKwNode<RefRoot<'a>>;
+
+impl<R1: TreeRoot<RaTypes>, R2: TreeRoot<RaTypes>> PartialEq<SelfKwNode<R1>> for SelfKwNode<R2> {
+    fn eq(&self, other: &SelfKwNode<R1>) -> bool { self.syntax == other.syntax }
+}
+impl<R: TreeRoot<RaTypes>> Eq for SelfKwNode<R> {}
+impl<R: TreeRoot<RaTypes>> Hash for SelfKwNode<R> {
+    fn hash<H: Hasher>(&self, state: &mut H) { self.syntax.hash(state) }
+}
+
+impl<'a> AstNode<'a> for SelfKw<'a> {
+    fn cast(syntax: SyntaxNodeRef<'a>) -> Option<Self> {
+        match syntax.kind() {
+            SELF_KW => Some(SelfKw { syntax }),
+            _ => None,
+        }
+    }
+    fn syntax(self) -> SyntaxNodeRef<'a> { self.syntax }
+}
+
+impl<R: TreeRoot<RaTypes>> SelfKwNode<R> {
+    pub fn borrowed(&self) -> SelfKw {
+        SelfKwNode { syntax: self.syntax.borrowed() }
+    }
+    pub fn owned(&self) -> SelfKwNode {
+        SelfKwNode { syntax: self.syntax.owned() }
+    }
+}
+
+
+impl<'a> SelfKw<'a> {}
+
 // SelfParam
 #[derive(Debug, Clone, Copy,)]
 pub struct SelfParamNode<R: TreeRoot<RaTypes> = OwnedRoot> {
@@ -3487,7 +3560,15 @@ impl<R: TreeRoot<RaTypes>> SelfParamNode<R> {
 }
 
 
-impl<'a> SelfParam<'a> {}
+impl<'a> SelfParam<'a> {
+    pub fn type_ref(self) -> Option<TypeRef<'a>> {
+        super::child_opt(self)
+    }
+
+    pub fn self_kw(self) -> Option<SelfKw<'a>> {
+        super::child_opt(self)
+    }
+}
 
 // SlicePat
 #[derive(Debug, Clone, Copy,)]
diff --git a/crates/ra_syntax/src/grammar.ron b/crates/ra_syntax/src/grammar.ron
index 9a4a96fac..c55e9e07a 100644
--- a/crates/ra_syntax/src/grammar.ron
+++ b/crates/ra_syntax/src/grammar.ron
@@ -284,6 +284,7 @@ Grammar(
             options: [ "ItemList" ]
         ),
         "ItemList": (
+            collections: [["impl_items", "ImplItem"]],
             traits: [ "FnDefOwner", "ModuleItemOwner" ],
         ),
         "ConstDef": ( traits: [
@@ -307,7 +308,7 @@ Grammar(
             "AttrsOwner",
             "DocCommentsOwner"
         ] ),
-        "ImplBlock": (collections: []),
+        "ImplBlock": (options: ["ItemList"]),
 
         "ParenType": (options: ["TypeRef"]),
         "TupleType": ( collections: [["fields", "TypeRef"]] ),
@@ -351,6 +352,9 @@ Grammar(
             enum: ["StructDef", "EnumDef", "FnDef", "TraitDef", "TypeDef", "ImplBlock",
                    "UseItem", "ExternCrateItem", "ConstDef", "StaticDef", "Module" ]
         ),
+        "ImplItem": (
+            enum: ["FnDef", "TypeDef", "ConstDef"]
+        ),
 
         "TupleExpr": (),
         "ArrayExpr": (),
@@ -530,7 +534,8 @@ Grammar(
                 ["params", "Param"]
             ]
         ),
-        "SelfParam": (),
+        "SelfParam": (options: ["TypeRef", "SelfKw"]),
+        "SelfKw": (),
         "Param": (
             options: [ "Pat", "TypeRef" ],
         ),
diff --git a/crates/ra_syntax/src/grammar/items.rs b/crates/ra_syntax/src/grammar/items.rs
index b9a00b565..265e84570 100644
--- a/crates/ra_syntax/src/grammar/items.rs
+++ b/crates/ra_syntax/src/grammar/items.rs
@@ -151,7 +151,7 @@ pub(super) fn maybe_item(p: &mut Parser, flavor: ItemFlavor) -> MaybeItem {
         // test unsafe_default_impl
         // unsafe default impl Foo {}
         IMPL_KW => {
-            traits::impl_item(p);
+            traits::impl_block(p);
             IMPL_BLOCK
         }
         _ => {
diff --git a/crates/ra_syntax/src/grammar/items/traits.rs b/crates/ra_syntax/src/grammar/items/traits.rs
index d4da8b2f7..0a0621753 100644
--- a/crates/ra_syntax/src/grammar/items/traits.rs
+++ b/crates/ra_syntax/src/grammar/items/traits.rs
@@ -40,9 +40,9 @@ pub(crate) fn trait_item_list(p: &mut Parser) {
     m.complete(p, ITEM_LIST);
 }
 
-// test impl_item
+// test impl_block
 // impl Foo {}
-pub(super) fn impl_item(p: &mut Parser) {
+pub(super) fn impl_block(p: &mut Parser) {
     assert!(p.at(IMPL_KW));
     p.bump();
     if choose_type_params_over_qpath(p) {
@@ -52,7 +52,7 @@ pub(super) fn impl_item(p: &mut Parser) {
     // TODO: never type
     // impl ! {}
 
-    // test impl_item_neg
+    // test impl_block_neg
     // impl !Send for X {}
     p.eat(EXCL);
     impl_type(p);