Module iter 

Iterator-backed ALTREP data adaptors.

Provides lazy backing data for ALTREP vectors from Rust iterators. Elements are generated on-demand and cached for repeat access.

Data adaptors, not R-facing vectors

The *Data types in these submodules implement only the data-level traits (AltrepLen + the matching Alt*Data trait). They do not implement RegisterAltrep, so they cannot back a live R SEXP by themselves. To expose one to R, wrap it in a concrete struct deriving the matching Altrep* derive with #[altrep(manual)] and delegate the data-trait methods to the inner adaptor (the derive cannot be applied to the adaptors directly because they are generic over the iterator type):

use miniextendr_api::altrep_data::{AltIntegerData, AltrepLen, IterIntData};

#[derive(miniextendr_api::AltrepInteger)]
#[altrep(class = "MyLazyInts", manual)]
struct MyLazyInts {
    inner: IterIntData<Box<dyn Iterator<Item = i32>>>,
}

impl AltrepLen for MyLazyInts {
    fn len(&self) -> usize {
        self.inner.len()
    }
}

impl AltIntegerData for MyLazyInts {
    fn elt(&self, i: usize) -> i32 {
        self.inner.elt(i)
    }
}

Submodules

• state: Core IterState<I, T> + standard data adaptors (Int, Real, Logical, Raw)
• coerce: Coerced variants (IterIntCoerceData, IterRealCoerceData, IterIntFromBoolData) plus the String/List/Complex data adaptors (IterStringData, IterListData, IterComplexData)
• sparse: Sparse iterators using nth() for skip-ahead (SparseIterState)
• windowed: Sliding-window iterators (WindowedIterState)

Re-exports

pub use coerce::*;

pub use sparse::*;

pub use state::*;

pub use windowed::*;

Modules

coerce 🔒

Iterator-backed ALTREP data adaptors with coercion support.

sparse 🔒

Sparse iterator-backed ALTREP data adaptors with skipping support.

state 🔒

Core iterator-backed ALTREP data adaptors.

windowed 🔒

Windowed iterator-backed ALTREP data adaptors.