Function metrics_from_tree 

pub fn metrics_from_tree(
    lang: &LANG,
    tree: Tree,
    source: Vec<u8>,
    path: &Path,
    pr: Option<Arc<PreprocResults>>,
    options: MetricsOptions,
) -> Result<FuncSpace, MetricsError>

Returns all function spaces data of a code, reusing a caller-supplied tree_sitter::Tree instead of running the bundled parser.

Use this when the caller already drives tree-sitter for other purposes (e.g. an editor doing incremental reparsing) and wants the metric walker to share that parse. The supplied tree must have been produced from source with the tree_sitter::Language returned by LANG::get_tree_sitter_language for lang; a mismatch is not unsafe but yields nonsensical metric values.

Equivalent to get_function_spaces_with_options on the same (lang, source, path) triple when the same tree is reproduced internally.

Examples

use std::path::PathBuf;

use big_code_analysis::{
    get_function_spaces, metrics_from_tree, tree_sitter, LANG,
    MetricsOptions,
};

let source_code = "fn main() { if true { 1 } else { 2 }; }";
let path = PathBuf::from("foo.rs");
let source = source_code.as_bytes().to_vec();

let mut parser = tree_sitter::Parser::new();
parser
    .set_language(
        &LANG::Rust
            .get_tree_sitter_language()
            .expect("rust feature enabled"),
    )
    .expect("rust grammar pinned to a compatible version");
let tree = parser
    .parse(&source, None)
    .expect("parser has a language set");

let from_tree = metrics_from_tree(
    &LANG::Rust,
    tree,
    source.clone(),
    &path,
    None,
    MetricsOptions::default(),
)
.unwrap();
let from_bytes =
    get_function_spaces(&LANG::Rust, source, &path, None).unwrap();

assert_eq!(
    from_tree.metrics.cyclomatic.cyclomatic_sum(),
    from_bytes.metrics.cyclomatic.cyclomatic_sum(),
);

Errors

Returns MetricsError::LanguageDisabled when lang’s per-language Cargo feature is not enabled in this build. The return type also carries MetricsError::EmptyRoot for forward compatibility, but the walker does not produce it today — see the variant doc.