rune/grammar/
classify.rs

1use crate::ast::Kind::*;
2
3use super::Node;
4
5#[derive(Debug, Clone, Copy)]
6pub(crate) enum NodeClass {
7    Const,
8    Local,
9    Item,
10    Expr,
11}
12
13/// Classify the kind of a node.
14pub(crate) fn classify(node: &Node<'_>) -> (bool, NodeClass) {
15    match node.kind() {
16        Local => return (true, NodeClass::Local),
17        Item => {
18            for node in node.children() {
19                let needs_semi = match node.kind() {
20                    ItemConst => return (true, NodeClass::Const),
21                    ItemStruct => node
22                        .children()
23                        .rev()
24                        .any(|n| matches!(n.kind(), TupleBody | EmptyBody)),
25                    ItemEnum | ItemFn | ItemImpl | ItemMod => false,
26                    ItemFileMod => true,
27                    _ => continue,
28                };
29
30                return (needs_semi, NodeClass::Item);
31            }
32        }
33        Expr => {
34            if node.children().rev().map(|n| n.kind()).any(|k| {
35                matches!(
36                    k,
37                    ExprIf | ExprFor | ExprWhile | ExprLoop | ExprMatch | ExprSelect | Block
38                )
39            }) {
40                return (false, NodeClass::Item);
41            }
42        }
43        _ => {}
44    }
45
46    (false, NodeClass::Expr)
47}