Struct ResidualSpec 

pub struct ResidualSpec { /* private fields */ }

Per-rule declaration of which primal inputs/outputs a transpose (VJP) rule reads as full tensor residuals versus which need only shape/dtype metadata.

The AD engine uses this to bound residual retention: an index not declared here may only be accessed through its metadata, never as a tensor operand. Indices are counted in primal-input order (input mask) and primal-output order (output mask).

Examples

use tenferro_ops::ad::ResidualSpec;

// `add` needs no tensor residuals; `mul` keeps both operands.
let add = ResidualSpec::none();
let mul = ResidualSpec::input(0).with_input(1);
assert!(add.is_empty());
assert!(mul.declares_input(0) && mul.declares_input(1));
// Unary ops that reuse the forward output (e.g. exp) declare it.
let exp = ResidualSpec::output(0);
assert!(exp.declares_output(0));

Implementations

impl ResidualSpec

pub const fn none() -> Self

A mask declaring no tensor residuals (metadata-only rule).

pub const fn input(index: usize) -> Self

A mask declaring one input index as a tensor residual.

pub const fn output(index: usize) -> Self

A mask declaring one output index as a tensor residual.

pub const fn with_input(self, index: usize) -> Self

Add one input index to this mask.

pub const fn with_output(self, index: usize) -> Self

Add one output index to this mask.

pub const fn with_all_inputs(self) -> Self

Add every input index to this mask.

pub const fn with_all_outputs(self) -> Self

Add every output index to this mask.

pub const fn all_inputs() -> Self

A mask declaring every input index as a tensor residual.

Used by rules whose required operand set depends on the active-input configuration (e.g. mul, concatenate, einsum), and by multi-op families whose individual ops collectively read any operand.

pub const fn all_outputs() -> Self

A mask declaring every output index as a tensor residual.

pub const fn declares_input(&self, index: usize) -> bool

Whether input index is declared as a tensor residual.

pub const fn declares_output(&self, index: usize) -> bool

Whether output index is declared as a tensor residual.

pub const fn is_empty(&self) -> bool

Whether this mask declares no tensor residuals.

Trait Implementations

impl Clone for ResidualSpec

fn clone(&self) -> ResidualSpec

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ResidualSpec

impl Debug for ResidualSpec

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

Formats the value using the given formatter.

impl Default for ResidualSpec

fn default() -> ResidualSpec

Returns the “default value” for a type.

impl Eq for ResidualSpec

impl PartialEq for ResidualSpec

fn eq(&self, other: &ResidualSpec) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ResidualSpec