Struct RngSeedContract 

pub(crate) struct RngSeedContract<'a> {
    pub formal: &'a str,
}

The seed contract of stats::simulate(), which #[miniextendr(rng(seed = <param>))] writes into a standalone wrapper in the order stats:::simulate.lm uses (#2198).

The prelude comes after the argument checks, so a refused argument changes no RNG state. It creates .Random.seed when it is missing. With a NULL seed it then remembers the state; otherwise it registers the restore of the session’s state with on.exit() and calls set.seed() with the value as passed, which validates it. The C wrapper’s GetRNGstate() then loads the seeded state, and its PutRNGstate() saves the state inside .Call(), before on.exit() puts the session’s state back, also when the body returns an error or panics. ATTRIBUTE records the seed in the result, after the result’s condition check.

Fields

formal: &'a str

The seed’s R formal.

Implementations

impl RngSeedContract<'_>

pub(crate) const ATTRIBUTE: &'static str = "if (!is.null(.val) && (is.atomic(.val) || \ is.list(.val))) attr(.val, \"seed\") <- .mx_rng_state"

The statement that gives the result .val its seed attribute. A value that can’t carry attributes (NULL, an environment, an external pointer, a function) is left as it is; NULL is tested on its own, since is.atomic(NULL) is TRUE before R 4.4.

pub(crate) fn prelude(&self, indent: &str) -> String

The statements before .Call(), each line after the first prefixed by indent.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 16 bytes