Struct FlatIndexer 

pub struct FlatIndexer { /* private fields */ }

Encodes multi-indices over fixed local dimensions as IndexKey values.

Dimension i occupies ceil(log2(d_i)) bits at a fixed offset, so distinct multi-indices always produce distinct keys.

Examples

use tensor4all_core::index_key::FlatIndexer;
let indexer = FlatIndexer::try_new(&[3, 4]).unwrap();
assert_eq!(indexer.width_bits(), 4);
assert_eq!(indexer.len(), 2);
assert!(indexer.encode(&[2, 3]).is_ok());
assert!(indexer.encode(&[3, 0]).is_err());

Implementations

impl FlatIndexer

pub fn try_new(local_dims: &[usize]) -> Result<Self, IndexKeyError>

Builds an indexer for local_dims.

Errors

Returns IndexKeyError::ZeroDimension when any dimension is zero and IndexKeyError::WidthOverflow when the packed width exceeds what this build can represent.

Examples

use tensor4all_core::index_key::FlatIndexer;
assert!(FlatIndexer::try_new(&[2, 3, 4]).is_ok());
assert!(FlatIndexer::try_new(&[2, 0]).is_err());

pub fn width_bits(&self) -> u64

Total packed width in bits.

pub fn len(&self) -> usize

Number of local dimensions.

pub fn is_empty(&self) -> bool

Whether the indexer has no dimensions.

pub fn encode(&self, idx: &[usize]) -> Result<IndexKey, IndexKeyError>

Encodes a multi-index.

Errors

Returns IndexKeyError::LengthMismatch when idx has the wrong length, and IndexKeyError::IndexOutOfRange when a component is not below its dimension. No input produces a silently wrapped key.

Examples

use tensor4all_core::index_key::FlatIndexer;
let indexer = FlatIndexer::try_new(&[2, 2]).unwrap();
assert!(indexer.encode(&[1, 1]).is_ok());
assert!(indexer.encode(&[2, 0]).is_err());
assert!(indexer.encode(&[0]).is_err());

Trait Implementations

impl Clone for FlatIndexer

fn clone(&self) -> FlatIndexer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FlatIndexer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.