sview 0.1.1

Agent-friendly structure views of source and document files
Documentation 
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
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147

use crate::{model::Node, util::truncate_preview};
use tree_sitter::{Node as AstNode, Parser};

pub(crate) fn analyze_rust(source: &str, preview_len: usize) -> Vec<Node> {
    let mut parser = Parser::new();
    parser
        .set_language(&tree_sitter_rust::LANGUAGE.into())
        .expect("tree-sitter Rust grammar is valid");
    let Some(tree) = parser.parse(source, None) else {
        return Vec::new();
    };

    let mut items = Vec::<RustItem>::new();
    collect_rust_items(
        tree.root_node(),
        source,
        preview_len,
        None,
        false,
        &mut items,
    );
    build_rust_tree(&items, None)
}

#[derive(Debug, Clone)]
struct RustItem {
    parent: Option<usize>,
    node: Node,
}

fn build_rust_tree(items: &[RustItem], parent: Option<usize>) -> Vec<Node> {
    items
        .iter()
        .enumerate()
        .filter(|(_, item)| item.parent == parent)
        .map(|(index, item)| {
            let mut node = item.node.clone();
            node.children = build_rust_tree(items, Some(index));
            node
        })
        .collect()
}

fn collect_rust_items(
    ast_node: AstNode,
    source: &str,
    preview_len: usize,
    parent: Option<usize>,
    has_test_attribute: bool,
    items: &mut Vec<RustItem>,
) {
    let current_parent =
        if let Some(node) = rust_node_from_ast(ast_node, source, preview_len, has_test_attribute) {
            let index = items.len();
            items.push(RustItem { parent, node });
            Some(index)
        } else {
            parent
        };

    let mut cursor = ast_node.walk();
    let mut pending_test_attribute = false;
    for child in ast_node.named_children(&mut cursor) {
        if child.kind() == "attribute_item" {
            pending_test_attribute = rust_is_test_attribute(child, source);
            continue;
        }

        collect_rust_items(
            child,
            source,
            preview_len,
            current_parent,
            pending_test_attribute,
            items,
        );
        pending_test_attribute = false;
    }
}

fn rust_node_from_ast(
    ast_node: AstNode,
    source: &str,
    preview_len: usize,
    has_test_attribute: bool,
) -> Option<Node> {
    let (kind, name) = match ast_node.kind() {
        "mod_item" => ("module", rust_ast_name(ast_node, source)?),
        "struct_item" => ("struct", rust_ast_name(ast_node, source)?),
        "enum_item" => ("enum", rust_ast_name(ast_node, source)?),
        "trait_item" => ("trait", rust_ast_name(ast_node, source)?),
        "impl_item" => ("impl", rust_impl_ast_name(ast_node, source)),
        "function_item" => {
            let kind = if has_test_attribute {
                "test"
            } else {
                "function"
            };
            (kind, rust_ast_name(ast_node, source)?)
        }
        _ => return None,
    };

    Some(Node {
        kind: kind.to_string(),
        level: None,
        name: Some(name),
        start_line: ast_node.start_position().row + 1,
        end_line: ast_node.end_position().row + 1,
        preview: rust_ast_preview(ast_node, source, preview_len),
        children: Vec::new(),
    })
}

fn rust_ast_name(ast_node: AstNode, source: &str) -> Option<String> {
    ast_node
        .child_by_field_name("name")
        .and_then(|node| node.utf8_text(source.as_bytes()).ok())
        .map(ToString::to_string)
}

fn rust_impl_ast_name(ast_node: AstNode, source: &str) -> String {
    let text = ast_node.utf8_text(source.as_bytes()).unwrap_or("impl");
    let signature = text
        .split('{')
        .next()
        .unwrap_or(text)
        .trim()
        .trim_end_matches(';')
        .trim();
    truncate_preview(signature, 80)
}

fn rust_is_test_attribute(ast_node: AstNode, source: &str) -> bool {
    ast_node
        .utf8_text(source.as_bytes())
        .is_ok_and(|text| text.starts_with("#[test") || text.starts_with("#[tokio::test"))
}

fn rust_ast_preview(ast_node: AstNode, source: &str, preview_len: usize) -> Option<String> {
    source
        .lines()
        .nth(ast_node.start_position().row)
        .map(str::trim)
        .filter(|line| !line.is_empty())
        .map(|line| truncate_preview(line, preview_len))
}