Struct Halo2Backend 

pub struct Halo2Backend<'ctx> { /* private fields */ }

Backend bundling the concrete halo2 chips and the circuit-building [Context]. The transcript is created lazily by TranscriptInst::init_transcript, mirroring TranscriptChip::new at the start of constrained_verify.

Implementations

impl<'ctx> Halo2Backend<'ctx>

pub fn new(range: Arc<RangeChip<Fr>>, ctx: &'ctx mut Context<Fr>) -> Self

pub fn from_ext_chip(ext: BabyBearExt4Chip, ctx: &'ctx mut Context<Fr>) -> Self

pub fn ext_chip(&self) -> &BabyBearExt4Chip

pub fn ctx_mut(&mut self) -> &mut Context<Fr>

Escape hatch for code that needs the raw context (e.g. test pranks).

Trait Implementations

impl BabyBearExt4Inst for Halo2Backend<'_>

fn ext_load_constant(&mut self, value: BabyBearExt4) -> BabyBearExt4Wire

fn ext_load_reduced_constant( &mut self, value: BabyBearExt4, ) -> ReducedBabyBearExt4Wire

fn ext_add( &mut self, a: BabyBearExt4Wire, b: BabyBearExt4Wire, ) -> BabyBearExt4Wire

fn ext_neg(&mut self, a: BabyBearExt4Wire) -> BabyBearExt4Wire

fn ext_sub( &mut self, a: BabyBearExt4Wire, b: BabyBearExt4Wire, ) -> BabyBearExt4Wire

fn ext_scalar_mul( &mut self, a: BabyBearExt4Wire, b: BabyBearWire, ) -> BabyBearExt4Wire

fn ext_scalar_mul_add( &mut self, a: BabyBearExt4Wire, b: BabyBearWire, c: BabyBearExt4Wire, ) -> BabyBearExt4Wire

a * b + c where b is a base-field scalar.

fn ext_assert_zero(&mut self, a: BabyBearExt4Wire)

fn ext_assert_equal(&mut self, a: BabyBearExt4Wire, b: BabyBearExt4Wire)

fn ext_mul( &mut self, a: BabyBearExt4Wire, b: BabyBearExt4Wire, ) -> BabyBearExt4Wire

fn ext_div( &mut self, a: BabyBearExt4Wire, b: BabyBearExt4Wire, ) -> BabyBearExt4Wire

fn ext_reduce_max_bits(&mut self, a: BabyBearExt4Wire) -> BabyBearExt4Wire

fn ext_zero(&mut self) -> BabyBearExt4Wire

fn ext_from_base_const(&mut self, value: BabyBear) -> BabyBearExt4Wire

fn ext_from_base_var(&mut self, value: BabyBearWire) -> BabyBearExt4Wire

fn ext_mul_base_const( &mut self, a: BabyBearExt4Wire, c: BabyBear, ) -> BabyBearExt4Wire

fn ext_square(&mut self, a: BabyBearExt4Wire) -> BabyBearExt4Wire

fn ext_pow_power_of_two( &mut self, a: BabyBearExt4Wire, n: usize, ) -> BabyBearExt4Wire

a^(2^n)

impl BabyBearInst for Halo2Backend<'_>

fn bb_load_constant(&mut self, value: BabyBear) -> BabyBearWire

fn bb_load_reduced_constant(&mut self, value: BabyBear) -> ReducedBabyBearWire

fn bb_reduce(&mut self, a: BabyBearWire) -> BabyBearWire

fn bb_reduce_max_bits(&mut self, a: BabyBearWire) -> BabyBearWire

fn bb_add(&mut self, a: BabyBearWire, b: BabyBearWire) -> BabyBearWire

fn bb_neg(&mut self, a: BabyBearWire) -> BabyBearWire

fn bb_sub(&mut self, a: BabyBearWire, b: BabyBearWire) -> BabyBearWire

fn bb_mul(&mut self, a: BabyBearWire, b: BabyBearWire) -> BabyBearWire

fn bb_mul_add( &mut self, a: BabyBearWire, b: BabyBearWire, c: BabyBearWire, ) -> BabyBearWire

a * b + c

fn bb_div(&mut self, a: BabyBearWire, b: BabyBearWire) -> BabyBearWire

fn bb_assert_zero(&mut self, a: BabyBearWire)

fn bb_assert_equal(&mut self, a: BabyBearWire, b: BabyBearWire)

fn bb_zero(&mut self) -> BabyBearWire

fn bb_one(&mut self) -> BabyBearWire

fn bb_mul_const(&mut self, a: BabyBearWire, c: BabyBear) -> BabyBearWire

fn bb_square(&mut self, a: BabyBearWire) -> BabyBearWire

fn bb_pow_power_of_two(&mut self, a: BabyBearWire, n: usize) -> BabyBearWire

a^(2^n)

impl ChipBase for Halo2Backend<'_>

type F = AssignedValue<Fr>

Wire/value representation abstracting AssignedValue<Fr>.

impl GateInst for Halo2Backend<'_>

fn load_constant(&mut self, value: Fr) -> AssignedValue<Fr>

fn constrain_equal(&mut self, a: AssignedValue<Fr>, b: AssignedValue<Fr>)

fn select( &mut self, when_true: AssignedValue<Fr>, when_false: AssignedValue<Fr>, cond: AssignedValue<Fr>, ) -> AssignedValue<Fr>

if cond { when_true } else { when_false }; cond must already be boolean-constrained.

fn select_const( &mut self, when_true: Fr, when_false: Fr, cond: AssignedValue<Fr>, ) -> AssignedValue<Fr>

Self::select with constant branch values.

fn num_to_bits( &mut self, a: AssignedValue<Fr>, range_bits: usize, ) -> Vec<AssignedValue<Fr>>

Little-endian bit decomposition, constrained to range_bits bits.

fn inner_product_const( &mut self, values: &[AssignedValue<Fr>], coeffs: &[Fr], ) -> AssignedValue<Fr>

Inner product of values with constant coefficients.

fn cell_count(&self) -> usize

Number of cells assigned so far (for cell profiling).

impl PopulateInputs for Halo2Backend<'_>

fn load_witness(&mut self, value: Fr) -> AssignedValue<Fr>

fn bb_load_reduced_witness(&mut self, value: BabyBear) -> ReducedBabyBearWire

fn ext_load_reduced_witness( &mut self, value: BabyBearExt4, ) -> ReducedBabyBearExt4Wire

impl Poseidon2Inst for Halo2Backend<'_>

fn hash_babybear_slice_to_digest( &mut self, values: &[ReducedBabyBearWire], ) -> AssignedValue<Fr>

Hash a slice of reduced BabyBear wires into a single Bn254 digest cell.

fn compress_digests( &mut self, left: AssignedValue<Fr>, right: AssignedValue<Fr>, ) -> AssignedValue<Fr>

Two-to-one Poseidon2 digest compression (Merkle node).

impl TranscriptInst for Halo2Backend<'_>

fn init_transcript(&mut self)

(Re)initialize the transcript sponge to the all-zero state.

fn observe(&mut self, value: &ReducedBabyBearWire)

fn observe_ext(&mut self, value: &ReducedBabyBearExt4Wire)

fn observe_commit(&mut self, digest: &DigestWire)

fn sample(&mut self) -> BabyBearWire

fn sample_ext(&mut self) -> BabyBearExt4Wire

fn sample_bits(&mut self, bits: usize) -> AssignedValue<Fr>

Sample and truncate to bits bits; returns a raw cell in [0, 2^bits).

fn check_witness(&mut self, bits: usize, witness: &ReducedBabyBearWire)

Asserts that the proof-of-work witness passes with bits leading zero bits.

fn transcript_load_reduced_constant( &mut self, value: BabyBear, ) -> ReducedBabyBearWire<Self::F>

Load a reduced constant through TranscriptChip’s baby-bear constant cache, which is distinct from BabyBearChip::const_cache. This split is preserved to keep the verifying key unchanged.