pub unsafe fn get_var_safe(symbol: SEXP, env: SEXP) -> Option<SEXP>Expand description
Returns a variable from an environment, or None if unbound.
On R < 4.5, uses Rf_findVar and checks against R_UnboundValue.
On R >= 4.5, uses R_getVar which signals an error if not found;
callers should wrap this with catch_r_error if needed.
ยงSafety
This function dereferences raw SEXP pointers.
The caller must ensure that symbol and env are valid SEXP pointers.