squawk_syntax/ast.rs
1// via https://github.com/rust-lang/rust-analyzer/blob/d8887c0758bbd2d5f752d5bd405d4491e90e7ed6/crates/syntax/src/ast.rs
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26
27mod generated;
28mod node_ext;
29mod nodes;
30mod support;
31mod token_ext;
32mod traits;
33
34use std::marker::PhantomData;
35
36use crate::syntax_node::{SyntaxNode, SyntaxNodeChildren, SyntaxToken};
37use squawk_parser::SyntaxKind;
38
39pub(crate) use self::node_ext::normalize_name_node;
40pub use self::{
41 generated::tokens::*,
42 node_ext::{BinOp, LitKind, PostfixOp},
43 nodes::*,
44 traits::{HasCreateTable, HasWithClause, NameLike},
45};
46
47/// The main trait to go from untyped `SyntaxNode` to a typed ast. The
48/// conversion itself has zero runtime cost: ast and syntax nodes have exactly
49/// the same representation: a pointer to the tree root and a pointer to the
50/// node itself.
51pub trait AstNode {
52 fn can_cast(kind: SyntaxKind) -> bool
53 where
54 Self: Sized;
55
56 fn cast(syntax: SyntaxNode) -> Option<Self>
57 where
58 Self: Sized;
59
60 fn syntax(&self) -> &SyntaxNode;
61 fn clone_for_update(&self) -> Self
62 where
63 Self: Sized,
64 {
65 Self::cast(self.syntax().clone_for_update()).unwrap()
66 }
67 fn clone_subtree(&self) -> Self
68 where
69 Self: Sized,
70 {
71 Self::cast(self.syntax().clone_subtree()).unwrap()
72 }
73}
74
75/// Like `AstNode`, but wraps tokens rather than interior nodes.
76pub trait AstToken {
77 fn can_cast(token: SyntaxKind) -> bool
78 where
79 Self: Sized;
80
81 fn cast(syntax: SyntaxToken) -> Option<Self>
82 where
83 Self: Sized;
84
85 fn syntax(&self) -> &SyntaxToken;
86
87 fn text(&self) -> &str {
88 self.syntax().text()
89 }
90}
91
92/// An iterator over `SyntaxNode` children of a particular AST type.
93#[derive(Debug, Clone)]
94pub struct AstChildren<N> {
95 inner: SyntaxNodeChildren,
96 ph: PhantomData<N>,
97}
98
99impl<N> AstChildren<N> {
100 fn new(parent: &SyntaxNode) -> Self {
101 AstChildren {
102 inner: parent.children(),
103 ph: PhantomData,
104 }
105 }
106}
107
108impl<N: AstNode> Iterator for AstChildren<N> {
109 type Item = N;
110 fn next(&mut self) -> Option<N> {
111 self.inner.find_map(N::cast)
112 }
113}