Rust Tree-sitter

Rust 对 Tree-sitter 解析库的绑定。

基本用法

首先创建一个解析器

use tree_sitter::{InputEdit, Language, Parser, Point};

let mut parser = Parser::new();

将 cc 包添加到你的 Cargo.toml 中的 [build-dependencies]

[build-dependencies]
cc="*"

然后添加一个语言作为依赖

[dependencies]
tree-sitter = "0.22"
tree-sitter-rust = "0.21"

为了使用语言，你需要将它们分配给解析器。

parser.set_language(&tree_sitter_rust::language()).expect("Error loading Rust grammar");

现在你可以解析源代码了

let source_code = "fn test() {}";
let mut tree = parser.parse(source_code, None).unwrap();
let root_node = tree.root_node();

assert_eq!(root_node.kind(), "source_file");
assert_eq!(root_node.start_position().column, 0);
assert_eq!(root_node.end_position().column, 12);

编辑

一旦你有了语法树，你可以在源代码更改时更新它。传入先前的编辑树可以使 parse 运行得更快

let new_source_code = "fn test(a: u32) {}";

tree.edit(&InputEdit {
  start_byte: 8,
  old_end_byte: 8,
  new_end_byte: 14,
  start_position: Point::new(0, 8),
  old_end_position: Point::new(0, 8),
  new_end_position: Point::new(0, 14),
});

let new_tree = parser.parse(new_source_code, Some(&tree));

文本输入

要解析的源代码可以是字符串、切片、向量或返回切片的函数。文本可以编码为 UTF8 或 UTF16

// Store some source code in an array of lines.
let lines = &[
    "pub fn foo() {",
    "  1",
    "}",
];

// Parse the source code using a custom callback. The callback is called
// with both a byte offset and a row/column offset.
let tree = parser.parse_with(&mut |_byte: usize, position: Point| -> &[u8] {
    let row = position.row as usize;
    let column = position.column as usize;
    if row < lines.len() {
        if column < lines[row].as_bytes().len() {
            &lines[row].as_bytes()[column..]
        } else {
            b"\n"
        }
    } else {
        &[]
    }
}, None).unwrap();

assert_eq!(
  tree.root_node().to_sexp(),
  "(source_file (function_item (visibility_modifier) (identifier) (parameters) (block (number_literal))))"
);