Repository: rust-analyzer/rust-analyzer
Pull request #10692 (2021-11-04 07:51:10)

minor: Migrate to new rowan
Since https://github.com/rust-analyzer/rowan/pull/122 was merged into rowan, this could be how rust-analyzer migrates.

lnicola: @azdavis would you mind updating this?
lnicola: I tried to look into it, but I'm not sure we can use `SyntaxNodePtr` from `rowan` because of the casts.

Patch:
diff --git a/crates/hir_expand/src/ast_id_map.rs b/crates/hir_expand/src/ast_id_map.rs
index 43c8a3db5c..c1ddef03ba 100644
--- a/crates/hir_expand/src/ast_id_map.rs
+++ b/crates/hir_expand/src/ast_id_map.rs
@@ -137,7 +137,7 @@ impl AstIdMap {
     }
 
     pub fn get<N: AstNode>(&self, id: FileAstId<N>) -> AstPtr<N> {
-        self.arena[id.raw].clone().cast::<N>().unwrap()
+        AstPtr::try_from_raw(self.arena[id.raw].clone()).unwrap()
     }
 
     fn alloc(&mut self, item: &SyntaxNode) -> ErasedFileAstId {
diff --git a/crates/syntax/src/ptr.rs b/crates/syntax/src/ptr.rs
index 57ae64cafe..4a54bed0d4 100644
--- a/crates/syntax/src/ptr.rs
+++ b/crates/syntax/src/ptr.rs
@@ -11,54 +11,15 @@
 
 use std::{
     hash::{Hash, Hasher},
-    iter::successors,
     marker::PhantomData,
 };
 
-use crate::{AstNode, SyntaxKind, SyntaxNode, TextRange};
+use crate::{syntax_node::RustLanguage, AstNode, SyntaxNode};
 
-/// A pointer to a syntax node inside a file. It can be used to remember a
-/// specific node across reparses of the same file.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct SyntaxNodePtr {
-    // Don't expose this field further. At some point, we might want to replace
-    // range with node id.
-    pub(crate) range: TextRange,
-    kind: SyntaxKind,
-}
-
-impl SyntaxNodePtr {
-    pub fn new(node: &SyntaxNode) -> SyntaxNodePtr {
-        SyntaxNodePtr { range: node.text_range(), kind: node.kind() }
-    }
-
-    /// "Dereference" the pointer to get the node it points to.
-    ///
-    /// Panics if node is not found, so make sure that `root` syntax tree is
-    /// equivalent (is build from the same text) to the tree which was
-    /// originally used to get this [`SyntaxNodePtr`].
-    ///
-    /// The complexity is linear in the depth of the tree and logarithmic in
-    /// tree width. As most trees are shallow, thinking about this as
-    /// `O(log(N))` in the size of the tree is not too wrong!
-    pub fn to_node(&self, root: &SyntaxNode) -> SyntaxNode {
-        assert!(root.parent().is_none());
-        successors(Some(root.clone()), |node| {
-            node.child_or_token_at_range(self.range).and_then(|it| it.into_node())
-        })
-        .find(|it| it.text_range() == self.range && it.kind() == self.kind)
-        .unwrap_or_else(|| panic!("can't resolve local ptr to SyntaxNode: {:?}", self))
-    }
-
-    pub fn cast<N: AstNode>(self) -> Option<AstPtr<N>> {
-        if !N::can_cast(self.kind) {
-            return None;
-        }
-        Some(AstPtr { raw: self, _ty: PhantomData })
-    }
-}
+/// A "pointer" to a [`SyntaxNode`], via location in the source code.
+pub type SyntaxNodePtr = rowan::ast::SyntaxNodePtr<RustLanguage>;
 
-/// Like `SyntaxNodePtr`, but remembers the type of node
+/// Like `SyntaxNodePtr`, but remembers the type of node.
 #[derive(Debug)]
 pub struct AstPtr<N: AstNode> {
     raw: SyntaxNodePtr,
@@ -100,11 +61,16 @@ impl<N: AstNode> AstPtr<N> {
     }
 
     pub fn cast<U: AstNode>(self) -> Option<AstPtr<U>> {
-        if !U::can_cast(self.raw.kind) {
+        if !U::can_cast(self.raw.kind()) {
             return None;
         }
         Some(AstPtr { raw: self.raw, _ty: PhantomData })
     }
+
+    /// Like `SyntaxNodePtr::cast` but the trait bounds work out.
+    pub fn try_from_raw(raw: SyntaxNodePtr) -> Option<AstPtr<N>> {
+        N::can_cast(raw.kind()).then(|| AstPtr { raw, _ty: PhantomData })
+    }
 }
 
 impl<N: AstNode> From<AstPtr<N>> for SyntaxNodePtr {


Test patch:
diff --git a/crates/ide_db/src/test_data/test_symbol_index_collection.txt b/crates/ide_db/src/test_data/test_symbol_index_collection.txt
index fe6eebc4f0..176d7e1579 100644
--- a/crates/ide_db/src/test_data/test_symbol_index_collection.txt
+++ b/crates/ide_db/src/test_data/test_symbol_index_collection.txt
@@ -21,12 +21,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 0..22,
                         kind: STRUCT,
+                        range: 0..22,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 6..21,
                         kind: NAME,
+                        range: 6..21,
                     },
                 },
                 kind: Struct,
@@ -43,12 +43,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 170..184,
                         kind: STRUCT,
+                        range: 170..184,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 177..183,
                         kind: NAME,
+                        range: 177..183,
                     },
                 },
                 kind: Struct,
@@ -65,12 +65,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 185..207,
                         kind: ENUM,
+                        range: 185..207,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 190..194,
                         kind: NAME,
+                        range: 190..194,
                     },
                 },
                 kind: Enum,
@@ -87,12 +87,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 208..222,
                         kind: UNION,
+                        range: 208..222,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 214..219,
                         kind: NAME,
+                        range: 214..219,
                     },
                 },
                 kind: Union,
@@ -109,12 +109,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 261..300,
                         kind: TRAIT,
+                        range: 261..300,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 267..272,
                         kind: NAME,
+                        range: 267..272,
                     },
                 },
                 kind: Trait,
@@ -131,12 +131,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 279..298,
                         kind: FN,
+                        range: 279..298,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 282..290,
                         kind: NAME,
+                        range: 282..290,
                     },
                 },
                 kind: Function,
@@ -155,12 +155,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 302..338,
                         kind: FN,
+                        range: 302..338,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 305..309,
                         kind: NAME,
+                        range: 305..309,
                     },
                 },
                 kind: Function,
@@ -177,12 +177,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 340..361,
                         kind: CONST,
+                        range: 340..361,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 346..351,
                         kind: NAME,
+                        range: 346..351,
                     },
                 },
                 kind: Const,
@@ -199,12 +199,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 362..396,
                         kind: STATIC,
+                        range: 362..396,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 369..375,
                         kind: NAME,
+                        range: 369..375,
                     },
                 },
                 kind: Static,
@@ -221,12 +221,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 397..417,
                         kind: TYPE_ALIAS,
+                        range: 397..417,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 402..407,
                         kind: NAME,
+                        range: 402..407,
                     },
                 },
                 kind: TypeAlias,
@@ -243,12 +243,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 419..457,
                         kind: MODULE,
+                        range: 419..457,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 423..428,
                         kind: NAME,
+                        range: 423..428,
                     },
                 },
                 kind: Module,
@@ -265,12 +265,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 520..592,
                         kind: CONST,
+                        range: 520..592,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 526..542,
                         kind: NAME,
+                        range: 526..542,
                     },
                 },
                 kind: Const,
@@ -287,12 +287,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 594..604,
                         kind: MODULE,
+                        range: 594..604,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 598..603,
                         kind: NAME,
+                        range: 598..603,
                     },
                 },
                 kind: Module,
@@ -309,12 +309,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 242..257,
                         kind: FN,
+                        range: 242..257,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 245..252,
                         kind: NAME,
+                        range: 245..252,
                     },
                 },
                 kind: Function,
@@ -331,12 +331,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 1..48,
                         kind: MACRO_RULES,
+                        range: 1..48,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 14..31,
                         kind: NAME,
+                        range: 14..31,
                     },
                 },
                 kind: Macro,
@@ -353,12 +353,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 51..131,
                         kind: MACRO_RULES,
+                        range: 51..131,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 64..77,
                         kind: NAME,
+                        range: 64..77,
                     },
                 },
                 kind: Macro,
@@ -375,12 +375,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 153..168,
                         kind: MACRO_DEF,
+                        range: 153..168,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 159..164,
                         kind: NAME,
+                        range: 159..164,
                     },
                 },
                 kind: Macro,
@@ -397,12 +397,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 479..507,
                         kind: STRUCT,
+                        range: 479..507,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 486..506,
                         kind: NAME,
+                        range: 486..506,
                     },
                 },
                 kind: Struct,
@@ -419,12 +419,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 555..581,
                         kind: STRUCT,
+                        range: 555..581,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 562..580,
                         kind: NAME,
+                        range: 562..580,
                     },
                 },
                 kind: Struct,
@@ -443,12 +443,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 318..336,
                         kind: STRUCT,
+                        range: 318..336,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 325..335,
                         kind: NAME,
+                        range: 325..335,
                     },
                 },
                 kind: Struct,
@@ -478,12 +478,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 435..455,
                         kind: STRUCT,
+                        range: 435..455,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 442..454,
                         kind: NAME,
+                        range: 442..454,
                     },
                 },
                 kind: Struct,
@@ -511,12 +511,12 @@
                         ),
                     ),
                     ptr: SyntaxNodePtr {
-                        range: 0..20,
                         kind: STRUCT,
+                        range: 0..20,
                     },
                     name_ptr: SyntaxNodePtr {
-                        range: 7..19,
                         kind: NAME,
+                        range: 7..19,
                     },
                 },
                 kind: Struct,