Unconstrained
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
Unconstrainedcan be empty when compiling, but never empty when running as the prover. (there is no way to create an emptyUnconstrainedin 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
• T
Properties
provable
static provable: Provable<Unconstrained<any>, Unconstrained<any>> & {
"empty": () => Unconstrained<any>;
"toInput": (x: Unconstrained<any>) => {
"fields": Field[];
"packed": [Field, number][];
};
};
Type declaration
empty()
empty: () => Unconstrained<any>;
Returns
Unconstrained\<any>
toInput()
toInput: (x: Unconstrained<any>) => {
"fields": Field[];
"packed": [Field, number][];
};
Parameters
• x: Unconstrained\<any>
Returns
{
"fields": Field[];
"packed": [Field, number][];
}
fields?
optional fields: Field[];
packed?
optional packed: [Field, number][];
Source
lib/provable/types/unconstrained.ts:114
Methods
get()
get(): T
Read an unconstrained value.
Note: Can only be called outside provable code.
Returns
T
Source
lib/provable/types/unconstrained.ts:53
set()
set(value: T): void
Modify the unconstrained value.
Parameters
• value: T
Returns
void
Source
lib/provable/types/unconstrained.ts:67
setTo()
setTo(value: Unconstrained<T>): void
Set the unconstrained value to the same as another Unconstrained.
Parameters
• value: Unconstrained\<T>
Returns
void
Source
lib/provable/types/unconstrained.ts:74
updateAsProver()
updateAsProver(compute: (value: T) => T): void
Update an Unconstrained by a witness computation.
Parameters
• compute
Returns
void
Source
lib/provable/types/unconstrained.ts:107
from()
static from<T>(value: T | Unconstrained<T>): 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
• T
Parameters
• value: T | Unconstrained\<T>
Returns
Unconstrained\<T>
Source
lib/provable/types/unconstrained.ts:89
provableWithEmpty()
static provableWithEmpty<T>(empty: T): Provable<Unconstrained<T>, Unconstrained<T>> & {
"empty": () => Unconstrained<T>;
"toInput": (x: Unconstrained<T>) => {
"fields": Field[];
"packed": [Field, number][];
};
}
Type parameters
• T
Parameters
• empty: T
Returns
Provable\<Unconstrained\<T>, Unconstrained\<T>> & {
"empty": () => Unconstrained\<T>;
"toInput": (x: Unconstrained\<T>) => {
"fields": Field[];
"packed": [Field, number][];
};
}
Source
lib/provable/types/unconstrained.ts:134
witness()
static witness<T>(compute: () => T): Unconstrained<T>
Create an Unconstrained from a witness computation.
Type parameters
• T
Parameters
• compute
Returns
Unconstrained\<T>