Struct ark_r1cs_std::fields::fp::AllocatedFp

pub struct AllocatedFp<F: PrimeField> {
    pub variable: Variable,
    pub cs: ConstraintSystemRef<F>,
    // some fields omitted
}

Represents a variable in the constraint system whose value can be an arbitrary field element.

Fields

variable: Variable

The allocated variable corresponding to self in self.cs.

cs: ConstraintSystemRef<F>

The constraint system that self was allocated in.

Implementations

impl<F: PrimeField> AllocatedFp<F>

pub fn new(
    value: Option<F>,
    variable: Variable,
    cs: ConstraintSystemRef<F>
) -> Self

Constructs a new AllocatedFp from a (optional) value, a low-level Variable, and a ConstraintSystemRef.

impl<F: PrimeField> AllocatedFp<F>

pub fn from(other: Boolean<F>) -> Self

Constructs Self from a Boolean: if other is false, this outputs zero, else it outputs one.

pub fn value(&self) -> Result<F, SynthesisError>

Returns the value assigned to self in the underlying constraint system (if a value was assigned).

pub fn add(&self, other: &Self) -> Self

Outputs self + other.

This does not create any constraints.

pub fn addmany<'a, I: Iterator<Item = &'a Self>>(iter: I) -> Self

Add many allocated Fp elements together.

This does not create any constraints and only creates one linear combination.

pub fn sub(&self, other: &Self) -> Self

Outputs self - other.

This does not create any constraints.

pub fn mul(&self, other: &Self) -> Self

Outputs self * other.

This requires one constraint.

pub fn add_constant(&self, other: F) -> Self

Output self + other

This does not create any constraints.

pub fn sub_constant(&self, other: F) -> Self

Output self - other

This does not create any constraints.

pub fn mul_constant(&self, other: F) -> Self

Output self * other

This does not create any constraints.

pub fn double(&self) -> Result<Self, SynthesisError>

Output self + self

This does not create any constraints.

pub fn negate(&self) -> Self

Output -self

This does not create any constraints.

pub fn negate_in_place(&mut self) -> &mut Self

Sets self = -self

This does not create any constraints.

pub fn square(&self) -> Result<Self, SynthesisError>

Outputs self * self

This requires one constraint.

pub fn inverse(&self) -> Result<Self, SynthesisError>

Outputs result such that result * self = 1.

This requires one constraint.

pub fn frobenius_map(&self, _: usize) -> Result<Self, SynthesisError>

This is a no-op for prime fields.

pub fn mul_equals(
    &self,
    other: &Self,
    result: &Self
) -> Result<(), SynthesisError>

Enforces that self * other = result.

This requires one constraint.

pub fn square_equals(&self, result: &Self) -> Result<(), SynthesisError>

Enforces that self * self = result.

This requires one constraint.

pub fn is_eq(&self, other: &Self) -> Result<Boolean<F>, SynthesisError>

Outputs the bit self == other.

This requires three constraints.

pub fn is_neq(&self, other: &Self) -> Result<Boolean<F>, SynthesisError>

Outputs the bit self != other.

This requires three constraints.

pub fn conditional_enforce_equal(
    &self,
    other: &Self,
    should_enforce: &Boolean<F>
) -> Result<(), SynthesisError>

Enforces that self == other if should_enforce.is_eq(&Boolean::TRUE).

This requires one constraint.

pub fn conditional_enforce_not_equal(
    &self,
    other: &Self,
    should_enforce: &Boolean<F>
) -> Result<(), SynthesisError>

Enforces that self != other if should_enforce.is_eq(&Boolean::TRUE).

This requires one constraint.

Trait Implementations

impl<F: PrimeField> AllocVar<F, F> for AllocatedFp<F>

fn new_variable<T: Borrow<F>>(
    cs: impl Into<Namespace<F>>,
    f: impl FnOnce() -> Result<T, SynthesisError>,
    mode: AllocationMode
) -> Result<Self, SynthesisError>

Allocates a new variable of type Self in the ConstraintSystem cs. The mode of allocation is decided by mode.

fn new_constant(
    cs: impl Into<Namespace<F>>,
    t: impl Borrow<V>
) -> Result<Self, SynthesisError>

Allocates a new constant of type Self in the ConstraintSystem cs.

fn new_input<T: Borrow<V>>(
    cs: impl Into<Namespace<F>>,
    f: impl FnOnce() -> Result<T, SynthesisError>
) -> Result<Self, SynthesisError>

Allocates a new public input of type Self in the ConstraintSystem cs.

fn new_witness<T: Borrow<V>>(
    cs: impl Into<Namespace<F>>,
    f: impl FnOnce() -> Result<T, SynthesisError>
) -> Result<Self, SynthesisError>

Allocates a new private witness of type Self in the ConstraintSystem cs.

impl<F: Clone + PrimeField> Clone for AllocatedFp<F>

fn clone(&self) -> AllocatedFp<F>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<F: PrimeField> CondSelectGadget<F> for AllocatedFp<F>

fn conditionally_select(
    cond: &Boolean<F>,
    true_val: &Self,
    false_val: &Self
) -> Result<Self, SynthesisError>

If cond == &Boolean::TRUE, then this returns true_value; else, returns false_value.

fn conditionally_select_power_of_two_vector(
    position: &[Boolean<ConstraintF>],
    values: &[Self]
) -> Result<Self, SynthesisError>

Returns an element of values whose index in represented by position. position is an array of boolean that represents an unsigned integer in big endian order.

impl<F: Debug + PrimeField> Debug for AllocatedFp<F>

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

Formats the value using the given formatter.

impl<F: PrimeField> From<AllocatedFp<F>> for FpVar<F>

fn from(other: AllocatedFp<F>) -> Self

Performs the conversion.

impl<F: PrimeField> ThreeBitCondNegLookupGadget<F> for AllocatedFp<F>

type TableConstant = F

The type of values being looked up.

fn three_bit_cond_neg_lookup(
    b: &[Boolean<F>],
    b0b1: &Boolean<F>,
    c: &[Self::TableConstant]
) -> Result<Self, SynthesisError>

Interprets the slice bits as a two-bit integer b = bits[0] + (bits[1] << 1), and then outputs constants[b] * c, where c = if bits[2] { -1 } else { 1 };.

impl<F: PrimeField> ToBitsGadget<F> for AllocatedFp<F>

---

---

fn to_bits_le(&self) -> Result<Vec<Boolean<F>>, SynthesisError>

Outputs the unique bit-wise decomposition of self in little-endian form.

This method enforces that the output is in the field, i.e. it invokes Boolean::enforce_in_field_le on the bit decomposition.

fn to_non_unique_bits_le(&self) -> Result<Vec<Boolean<F>>, SynthesisError>

Outputs a possibly non-unique little-endian bit-wise representation of self.

fn to_bits_be(&self) -> Result<Vec<Boolean<F>>, SynthesisError>

Outputs the canonical big-endian bit-wise representation of self.

fn to_non_unique_bits_be(&self) -> Result<Vec<Boolean<F>>, SynthesisError>

Outputs a possibly non-unique big-endian bit-wise representation of self.

impl<F: PrimeField> ToBytesGadget<F> for AllocatedFp<F>

fn to_bytes(&self) -> Result<Vec<UInt8<F>>, SynthesisError>

Outputs the unique byte decomposition of self in little-endian form.

This method enforces that the decomposition represents an integer that is less than F::MODULUS.

fn to_non_unique_bytes(&self) -> Result<Vec<UInt8<F>>, SynthesisError>

Outputs a possibly non-unique byte decomposition of self.

impl<F: PrimeField> ToConstraintFieldGadget<F> for AllocatedFp<F>

fn to_constraint_field(&self) -> Result<Vec<FpVar<F>>, SynthesisError>

Converts self to FpVar<ConstraintF> variables.

impl<F: PrimeField> TwoBitLookupGadget<F> for AllocatedFp<F>

Uses two bits to perform a lookup into a table b is little-endian: b[0] is LSB.

type TableConstant = F

The type of values being looked up.

fn two_bit_lookup(
    b: &[Boolean<F>],
    c: &[Self::TableConstant]
) -> Result<Self, SynthesisError>

Interprets the slice bits as a two-bit integer b = bits[0] + (bits[1] << 1), and then outputs constants[b].