snarkvm-circuit-program 4.6.1

// Copyright (c) 2019-2026 Provable Inc.
// This file is part of the snarkVM library.

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at:

// http://www.apache.org/licenses/LICENSE-2.0

// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use super::*;

impl<E: Environment> Cast<Address<E>> for Scalar<E> {
    /// Casts a `Scalar` to an `Address`.
    ///
    /// This operation converts the scalar to a field element, and then attempts to recover
    /// the group element by treating the field element as an x-coordinate. The group element
    /// is then converted to an address.
    ///
    /// To cast arbitrary scalars to addresses, use `Scalar::cast_lossy`.
    #[inline]
    fn cast(&self) -> Address<E> {
        let field: Field<E> = self.cast();
        Address::from_field(field)
    }
}

impl<E: Environment> Cast<Boolean<E>> for Scalar<E> {
    /// Casts a `Scalar` to a `Boolean`, if the scalar is zero or one.
    ///
    /// To cast arbitrary scalars to booleans, use `Scalar::cast_lossy`.
    #[inline]
    fn cast(&self) -> Boolean<E> {
        let is_one = self.is_one();
        E::assert(self.is_zero().bitor(&is_one)).expect("Scalar must be zero or one to cast to Boolean");
        is_one
    }
}

impl<E: Environment> Cast<Group<E>> for Scalar<E> {
    /// Casts a `Scalar` to a `Group`.
    ///
    /// This operation converts the scalar to a field element, and then attempts to recover
    /// the group element by treating the field element as an x-coordinate.
    ///
    /// To cast arbitrary scalars to groups, use `Scalar::cast_lossy`.
    #[inline]
    fn cast(&self) -> Group<E> {
        let field: Field<E> = self.cast();
        Group::from_x_coordinate(field)
    }
}

impl<E: Environment> Cast<Field<E>> for Scalar<E> {
    /// Casts a `Scalar` to a `Field`.
    #[inline]
    fn cast(&self) -> Field<E> {
        self.to_field()
    }
}

impl<E: Environment, I: IntegerType> Cast<Integer<E, I>> for Scalar<E> {
    /// Casts a `Scalar` to an `Integer`, if the scalar is in the range of the integer.
    ///
    /// To cast arbitrary scalars to integers, via truncation, use `Scalar::cast_lossy`.
    #[inline]
    fn cast(&self) -> Integer<E, I> {
        let bits_le = self.to_bits_le();
        Integer::<E, I>::from_bits_le(&bits_le)
    }
}

impl<E: Environment> Cast<Scalar<E>> for Scalar<E> {
    /// Casts a `Scalar` to a `Scalar`.
    #[inline]
    fn cast(&self) -> Scalar<E> {
        self.clone()
    }
}

impl<E: Environment> Cast<IdentifierLiteral<E>> for Scalar<E> {
    /// Casts a `Scalar` to an `IdentifierLiteral`.
    ///
    /// This operation converts the scalar to a field element, and then attempts to
    /// create an identifier literal from that field element.
    #[inline]
    fn cast(&self) -> IdentifierLiteral<E> {
        let field: Field<E> = self.cast();
        field.cast()
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use console::Cast as _;
    use console_root::{
        network::MainnetV0,
        prelude::{One, TestRng, Uniform, Zero},
    };
    use snarkvm_circuit_types::environment::{Circuit, Eject, Inject, Mode, UpdatableCount, count_is, count_less_than};

    use std::fmt::Debug;

    const ITERATIONS: usize = 10;

    fn sample_values(
        i: usize,
        mode: Mode,
        rng: &mut TestRng,
    ) -> (console_root::types::Scalar<MainnetV0>, Scalar<Circuit>) {
        let console_value = match i {
            0 => console_root::types::Scalar::<MainnetV0>::zero(),
            1 => console_root::types::Scalar::<MainnetV0>::one(),
            _ => Uniform::rand(rng),
        };
        let circuit_value = Scalar::<Circuit>::new(mode, console_value);
        (console_value, circuit_value)
    }

    impl_check_cast!(cast, Scalar<Circuit>, console_root::types::Scalar::<MainnetV0>);

    #[test]
    fn test_scalar_to_address() {
        check_cast::<Address<Circuit>, console_root::types::Address<MainnetV0>>(
            Mode::Constant,
            count_less_than!(11, 0, 0, 0),
        );
        check_cast::<Address<Circuit>, console_root::types::Address<MainnetV0>>(Mode::Public, count_is!(4, 0, 13, 13));
        check_cast::<Address<Circuit>, console_root::types::Address<MainnetV0>>(Mode::Private, count_is!(4, 0, 13, 13));
    }

    #[test]
    fn test_scalar_to_boolean() {
        check_cast::<Boolean<Circuit>, console_root::types::Boolean<MainnetV0>>(Mode::Constant, count_is!(4, 0, 0, 0));
        check_cast::<Boolean<Circuit>, console_root::types::Boolean<MainnetV0>>(Mode::Public, count_is!(2, 0, 5, 6));
        check_cast::<Boolean<Circuit>, console_root::types::Boolean<MainnetV0>>(Mode::Private, count_is!(2, 0, 5, 6));
    }

    #[test]
    fn test_scalar_to_field() {
        check_cast::<Field<Circuit>, console_root::types::Field<MainnetV0>>(Mode::Constant, count_is!(0, 0, 0, 0));
        check_cast::<Field<Circuit>, console_root::types::Field<MainnetV0>>(Mode::Public, count_is!(0, 0, 0, 0));
        check_cast::<Field<Circuit>, console_root::types::Field<MainnetV0>>(Mode::Private, count_is!(0, 0, 0, 0));
    }

    #[test]
    fn test_scalar_to_group() {
        check_cast::<Group<Circuit>, console_root::types::Group<MainnetV0>>(
            Mode::Constant,
            count_less_than!(11, 0, 0, 0),
        );
        check_cast::<Group<Circuit>, console_root::types::Group<MainnetV0>>(Mode::Public, count_is!(4, 0, 13, 13));
        check_cast::<Group<Circuit>, console_root::types::Group<MainnetV0>>(Mode::Private, count_is!(4, 0, 13, 13));
    }

    #[test]
    fn test_scalar_to_i8() {
        check_cast::<I8<Circuit>, console_root::types::I8<MainnetV0>>(Mode::Constant, count_is!(251, 0, 0, 0));
        check_cast::<I8<Circuit>, console_root::types::I8<MainnetV0>>(Mode::Public, count_is!(0, 0, 501, 504));
        check_cast::<I8<Circuit>, console_root::types::I8<MainnetV0>>(Mode::Private, count_is!(0, 0, 501, 504));
    }

    #[test]
    fn test_scalar_to_i16() {
        check_cast::<I16<Circuit>, console_root::types::I16<MainnetV0>>(Mode::Constant, count_is!(251, 0, 0, 0));
        check_cast::<I16<Circuit>, console_root::types::I16<MainnetV0>>(Mode::Public, count_is!(0, 0, 501, 504));
        check_cast::<I16<Circuit>, console_root::types::I16<MainnetV0>>(Mode::Private, count_is!(0, 0, 501, 504));
    }

    #[test]
    fn test_scalar_to_i32() {
        check_cast::<I32<Circuit>, console_root::types::I32<MainnetV0>>(Mode::Constant, count_is!(251, 0, 0, 0));
        check_cast::<I32<Circuit>, console_root::types::I32<MainnetV0>>(Mode::Public, count_is!(0, 0, 501, 504));
        check_cast::<I32<Circuit>, console_root::types::I32<MainnetV0>>(Mode::Private, count_is!(0, 0, 501, 504));
    }

    #[test]
    fn test_scalar_to_i64() {
        check_cast::<I64<Circuit>, console_root::types::I64<MainnetV0>>(Mode::Constant, count_is!(251, 0, 0, 0));
        check_cast::<I64<Circuit>, console_root::types::I64<MainnetV0>>(Mode::Public, count_is!(0, 0, 501, 504));
        check_cast::<I64<Circuit>, console_root::types::I64<MainnetV0>>(Mode::Private, count_is!(0, 0, 501, 504));
    }

    #[test]
    fn test_scalar_to_i128() {
        check_cast::<I128<Circuit>, console_root::types::I128<MainnetV0>>(Mode::Constant, count_is!(251, 0, 0, 0));
        check_cast::<I128<Circuit>, console_root::types::I128<MainnetV0>>(Mode::Public, count_is!(0, 0, 501, 504));
        check_cast::<I128<Circuit>, console_root::types::I128<MainnetV0>>(Mode::Private, count_is!(0, 0, 501, 504));
    }

    #[test]
    fn test_scalar_to_scalar() {
        check_cast::<Scalar<Circuit>, console_root::types::Scalar<MainnetV0>>(Mode::Constant, count_is!(0, 0, 0, 0));
        check_cast::<Scalar<Circuit>, console_root::types::Scalar<MainnetV0>>(Mode::Public, count_is!(0, 0, 0, 0));
        check_cast::<Scalar<Circuit>, console_root::types::Scalar<MainnetV0>>(Mode::Private, count_is!(0, 0, 0, 0));
    }

    #[test]
    fn test_scalar_to_u8() {
        check_cast::<U8<Circuit>, console_root::types::U8<MainnetV0>>(Mode::Constant, count_is!(251, 0, 0, 0));
        check_cast::<U8<Circuit>, console_root::types::U8<MainnetV0>>(Mode::Public, count_is!(0, 0, 501, 504));
        check_cast::<U8<Circuit>, console_root::types::U8<MainnetV0>>(Mode::Private, count_is!(0, 0, 501, 504));
    }

    #[test]
    fn test_scalar_to_u16() {
        check_cast::<U16<Circuit>, console_root::types::U16<MainnetV0>>(Mode::Constant, count_is!(251, 0, 0, 0));
        check_cast::<U16<Circuit>, console_root::types::U16<MainnetV0>>(Mode::Public, count_is!(0, 0, 501, 504));
        check_cast::<U16<Circuit>, console_root::types::U16<MainnetV0>>(Mode::Private, count_is!(0, 0, 501, 504));
    }

    #[test]
    fn test_scalar_to_u32() {
        check_cast::<U32<Circuit>, console_root::types::U32<MainnetV0>>(Mode::Constant, count_is!(251, 0, 0, 0));
        check_cast::<U32<Circuit>, console_root::types::U32<MainnetV0>>(Mode::Public, count_is!(0, 0, 501, 504));
        check_cast::<U32<Circuit>, console_root::types::U32<MainnetV0>>(Mode::Private, count_is!(0, 0, 501, 504));
    }

    #[test]
    fn test_scalar_to_u64() {
        check_cast::<U64<Circuit>, console_root::types::U64<MainnetV0>>(Mode::Constant, count_is!(251, 0, 0, 0));
        check_cast::<U64<Circuit>, console_root::types::U64<MainnetV0>>(Mode::Public, count_is!(0, 0, 501, 504));
        check_cast::<U64<Circuit>, console_root::types::U64<MainnetV0>>(Mode::Private, count_is!(0, 0, 501, 504));
    }

    #[test]
    fn test_scalar_to_u128() {
        check_cast::<U128<Circuit>, console_root::types::U128<MainnetV0>>(Mode::Constant, count_is!(251, 0, 0, 0));
        check_cast::<U128<Circuit>, console_root::types::U128<MainnetV0>>(Mode::Public, count_is!(0, 0, 501, 504));
        check_cast::<U128<Circuit>, console_root::types::U128<MainnetV0>>(Mode::Private, count_is!(0, 0, 501, 504));
    }
}