Function parse_and_then

plugins/ast/python/src/lib.rs:113–147

Decode UTF-8 source, parse with [`parse_module`], run `extract`, serialize, and `report`. Returns 0 on invalid UTF-8, a syntax error, or an empty result (host falls back).

(
    source: *const u8,
    length: usize,
    extract: impl Fn(&[Statement]) -> Vec<T>,
)

/// `report`. Returns 0 on invalid UTF-8, a syntax error, or an empty result (host
/// falls back).
unsafe fn parse_and_then<T: serde::Serialize>(
    source: *const u8,
    length: usize,
    extract: impl Fn(&[Statement]) -> Vec<T>,
) -> u64 {
    let bytes = unsafe {
        core::slice::from_raw_parts(source, length)
    };

    let Ok(source) = core::str::from_utf8(bytes) else {
        return 0;
    };

    let Ok(parsed) = parse_module(source).map(Parsed::into_syntax) else {
        return 0;
    };

    let Ok(extracted) = serde_json::to_string(&extract(&parsed.body)) else {
        return 0;
    };

    if extracted.is_empty()
        || extracted
            .split_ascii_whitespace()
            .collect::<Vec<_>>()
            .join("")
            == "[]"
    {
        return 0;
    }

    unsafe {
        report(extracted.as_bytes())
    }
}

/// Copy `bytes` into a fresh host-owned allocation and pack (ptr << 32) | len.
unsafe fn report(bytes: &[u8]) -> u64 {