Function pre_eval_alist 

fn pre_eval_alist(
    args: &[Arg],
    _env: &Environment,
    _context: &BuiltinContext<'_>,
) -> Result<RValue, RError>

Construct a pairlist of unevaluated arguments.

Unlike list(), alist() does not evaluate its arguments. Missing arguments (e.g. alist(x = )) produce empty symbol names, matching R’s convention for function formals.

@param … unevaluated arguments @return a list of language objects