Function parse_script_with_preseed 

pub fn parse_script_with_preseed(
    input: &str,
    lower: impl Fn(&str, Vec<Arg>) -> ParseResult<StepKind>,
    reserved_names: HashSet<String>,
    modules: ModuleTable,
    preseed_funcs: HashSet<String>,
    preseed_imports: Vec<String>,
) -> ParseResult<Vec<Step>>

Parse a snippet with an enclosing parse’s visible scope state, so re-parsed inner commands (async bodies) resolve calls identically. The snippet never defines, only reads: seeds affect lookup alone.