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Unconstrained

o1js / Modules / Unconstrained

Class: Unconstrained\<T>

Container which holds an unconstrained value. This can be used to pass values between the out-of-circuit blocks in provable code.

Invariants:

  • An Unconstrained's value can only be accessed in auxiliary contexts.
  • An Unconstrained can be empty when compiling, but never empty when running as the prover. (there is no way to create an empty Unconstrained in the prover)

Example

let x = Unconstrained.from(0n);

class MyContract extends SmartContract {
  `@method` myMethod(x: Unconstrained<bigint>) {

    Provable.witness(Field, () => {
      // we can access and modify `x` here
      let newValue = x.get() + otherField.toBigInt();
      x.set(newValue);

      // ...
    });

    // throws an error!
    x.get();
  }

Type parameters​

Name
T

Table of contents​

Constructors​

Properties​

Methods​

Constructors​

constructor​

• Private new Unconstrained\<T>(isSome, value?)

Type parameters​

Name
T

Parameters​

NameType
isSomeboolean
value?T

Defined in​

lib/circuit-value.ts:533

Properties​

option​

• Private option: { isSome: true ; value: T } | { isSome: false ; value: undefined }

Defined in​

lib/circuit-value.ts:529

provable​

▪ Static provable: Provable\<Unconstrained\<any>> & { toInput: (x: Unconstrained\<any>) => { fields?: Field[] ; packed?: [Field, number][] } }

Defined in​

lib/circuit-value.ts:602

Methods​

get​

▸ get(): T

Read an unconstrained value.

Note: Can only be called outside provable code.

Returns​

T

Defined in​

lib/circuit-value.ts:542

set​

▸ set(value): void

Modify the unconstrained value.

Parameters​

NameType
valueT

Returns​

void

Defined in​

lib/circuit-value.ts:556

setTo​

▸ setTo(value): void

Set the unconstrained value to the same as another Unconstrained.

Parameters​

NameType
valueUnconstrained\<T>

Returns​

void

Defined in​

lib/circuit-value.ts:563

updateAsProver​

▸ updateAsProver(compute): void

Update an Unconstrained by a witness computation.

Parameters​

NameType
compute(value: T) => T

Returns​

void

Defined in​

lib/circuit-value.ts:595

from​

▸ Static from\<T>(value): Unconstrained\<T>

Create an Unconstrained with the given value.

Note: If T contains provable types, Unconstrained.from is an anti-pattern, because it stores witnesses in a space that's intended to be used outside the proof. Something like the following should be used instead:

let xWrapped = Unconstrained.witness(() => Provable.toConstant(type, x));

Type parameters​

Name
T

Parameters​

NameType
valueT

Returns​

Unconstrained\<T>

Defined in​

lib/circuit-value.ts:578

witness​

▸ Static witness\<T>(compute): Unconstrained\<T>

Create an Unconstrained from a witness computation.

Type parameters​

Name
T

Parameters​

NameType
compute() => T

Returns​

Unconstrained\<T>

Defined in​

lib/circuit-value.ts:585