1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
//! FIXME: write short doc here
use std::{
hash::{Hash, Hasher},
iter::successors,
marker::PhantomData,
};
use crate::{AstNode, SyntaxKind, SyntaxNode, TextRange};
/// 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() }
}
pub fn text_range(&self) -> TextRange {
self.range.clone()
}
pub fn to_node(&self, root: &SyntaxNode) -> SyntaxNode {
assert!(root.parent().is_none());
successors(Some(root.clone()), |node| {
node.children().find(|it| it.text_range().contains_range(self.range))
})
.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 })
}
}
/// Like `SyntaxNodePtr`, but remembers the type of node
#[derive(Debug)]
pub struct AstPtr<N: AstNode> {
raw: SyntaxNodePtr,
_ty: PhantomData<fn() -> N>,
}
impl<N: AstNode> Clone for AstPtr<N> {
fn clone(&self) -> AstPtr<N> {
AstPtr { raw: self.raw.clone(), _ty: PhantomData }
}
}
impl<N: AstNode> Eq for AstPtr<N> {}
impl<N: AstNode> PartialEq for AstPtr<N> {
fn eq(&self, other: &AstPtr<N>) -> bool {
self.raw == other.raw
}
}
impl<N: AstNode> Hash for AstPtr<N> {
fn hash<H: Hasher>(&self, state: &mut H) {
self.raw.hash(state)
}
}
impl<N: AstNode> AstPtr<N> {
pub fn new(node: &N) -> AstPtr<N> {
AstPtr { raw: SyntaxNodePtr::new(node.syntax()), _ty: PhantomData }
}
pub fn to_node(&self, root: &SyntaxNode) -> N {
let syntax_node = self.raw.to_node(root);
N::cast(syntax_node).unwrap()
}
pub fn syntax_node_ptr(&self) -> SyntaxNodePtr {
self.raw.clone()
}
pub fn cast<U: AstNode>(self) -> Option<AstPtr<U>> {
if !U::can_cast(self.raw.kind) {
return None;
}
Some(AstPtr { raw: self.raw, _ty: PhantomData })
}
}
impl<N: AstNode> From<AstPtr<N>> for SyntaxNodePtr {
fn from(ptr: AstPtr<N>) -> SyntaxNodePtr {
ptr.raw
}
}
#[test]
fn test_local_syntax_ptr() {
use crate::{ast, AstNode, SourceFile};
let file = SourceFile::parse("struct Foo { f: u32, }").ok().unwrap();
let field = file.syntax().descendants().find_map(ast::RecordField::cast).unwrap();
let ptr = SyntaxNodePtr::new(field.syntax());
let field_syntax = ptr.to_node(file.syntax());
assert_eq!(field.syntax(), &field_syntax);
}
|
