Function builtin_unlist 

fn builtin_unlist(
    args: &[RValue],
    named: &[(String, RValue)],
) -> Result<RValue, RError>

Flatten a list into an atomic vector.

When recursive = TRUE (default), recursively flattens all nested lists into a single atomic vector using the same coercion rules as c(). When recursive = FALSE, flattens only one level of list nesting.

@param x list to flatten @param recursive whether to flatten recursively (default: TRUE) @return atomic vector