delsum-lib 0.1.1

use num_traits::Num;
use std::ops;
/// Me: can I have a trait for either u8, u16, u32, u64 or u128?
/// Mom: We have a trait for either u8, u16, u32, u64 or u128 at home
/// trait for either u8, u16, u32, u64 or u128 at home:
pub trait BitNum:
    Num
    + num_traits::ops::wrapping::WrappingSub
    + num_traits::ops::wrapping::WrappingAdd
    + num_traits::ops::wrapping::WrappingMul
    + num_traits::ops::checked::CheckedSub
    + num_traits::ops::checked::CheckedAdd
    + num_traits::ops::checked::CheckedMul
    + ops::BitXor<Output = Self>
    + ops::Shl<usize, Output = Self>
    + ops::Shr<usize, Output = Self>
    + ops::BitAnd<Output = Self>
    + ops::Not<Output = Self>
    + Clone
    + Copy
    + Eq
    + Ord
    + From<u8>
    + std::convert::TryInto<u8>
    + std::fmt::Debug
    + std::fmt::LowerHex
    + std::fmt::UpperHex
    + Send
    + Sync
{
    fn revbits(self) -> Self;
    fn bits(&self) -> usize;
    fn trail_zeros(&self) -> u32;
    fn from_hex(s: &str) -> Result<Self, Self::FromStrRadixErr> {
        match s.strip_prefix("0x") {
            Some(remain) => Self::from_str_radix(remain, 16),
            None => Self::from_str_radix(s, 16),
        }
    }
}

impl BitNum for u8 {
    fn revbits(self) -> Self {
        self.reverse_bits()
    }
    fn bits(&self) -> usize {
        8
    }

    fn trail_zeros(&self) -> u32 {
        self.trailing_zeros()
    }
}
impl BitNum for u16 {
    fn revbits(self) -> Self {
        self.reverse_bits()
    }
    fn bits(&self) -> usize {
        16
    }

    fn trail_zeros(&self) -> u32 {
        self.trailing_zeros()
    }
}
impl BitNum for u32 {
    fn revbits(self) -> Self {
        self.reverse_bits()
    }
    fn bits(&self) -> usize {
        32
    }

    fn trail_zeros(&self) -> u32 {
        self.trailing_zeros()
    }
}
impl BitNum for u64 {
    fn revbits(self) -> Self {
        self.reverse_bits()
    }
    fn bits(&self) -> usize {
        64
    }

    fn trail_zeros(&self) -> u32 {
        self.trailing_zeros()
    }
}
impl BitNum for u128 {
    fn revbits(self) -> Self {
        self.reverse_bits()
    }
    fn bits(&self) -> usize {
        128
    }

    fn trail_zeros(&self) -> u32 {
        self.trailing_zeros()
    }
}

/// For the modsum, we need a wider type for temporary reduction modulo some number,
/// so this is implemented in this type (and there's probably no need for an u128 ModSum anyway)
pub trait Modnum: BitNum {
    fn add_mod(self, rhs: &Self, modulo: &Self) -> Self;
    fn mul_mod(self, rhs: &Self, modulo: &Self) -> Self;
}
// the same stuff a bunch of times (not u128 because i can't be bothered)
impl Modnum for u8 {
    fn add_mod(self, rhs: &Self, modulo: &Self) -> Self {
        if *modulo != 0 {
            ((u16::from(self) + u16::from(*rhs)) % u16::from(*modulo)) as u8
        } else {
            (u16::from(self) + u16::from(*rhs)) as u8
        }
    }
    fn mul_mod(self, rhs: &Self, modulo: &Self) -> Self {
        if *modulo != 0 {
            ((u16::from(self) * u16::from(*rhs)) % u16::from(*modulo)) as u8
        } else {
            (u16::from(self) * u16::from(*rhs)) as u8
        }
    }
}
impl Modnum for u16 {
    fn add_mod(self, rhs: &Self, modulo: &Self) -> Self {
        if *modulo != 0 {
            ((u32::from(self) + u32::from(*rhs)) % u32::from(*modulo)) as u16
        } else {
            (u32::from(self) + u32::from(*rhs)) as u16
        }
    }
    fn mul_mod(self, rhs: &Self, modulo: &Self) -> Self {
        if *modulo != 0 {
            ((u32::from(self) * u32::from(*rhs)) % u32::from(*modulo)) as u16
        } else {
            (u32::from(self) * u32::from(*rhs)) as u16
        }
    }
}
impl Modnum for u32 {
    fn add_mod(self, rhs: &Self, modulo: &Self) -> Self {
        if *modulo != 0 {
            ((u64::from(self) + u64::from(*rhs)) % u64::from(*modulo)) as u32
        } else {
            (u64::from(self) + u64::from(*rhs)) as u32
        }
    }
    fn mul_mod(self, rhs: &Self, modulo: &Self) -> Self {
        if *modulo != 0 {
            ((u64::from(self) * u64::from(*rhs)) % u64::from(*modulo)) as u32
        } else {
            (u64::from(self) * u64::from(*rhs)) as u32
        }
    }
}
impl Modnum for u64 {
    fn add_mod(self, rhs: &Self, modulo: &Self) -> Self {
        if *modulo != 0 {
            ((u128::from(self) + u128::from(*rhs)) % u128::from(*modulo)) as u64
        } else {
            (u128::from(self) + u128::from(*rhs)) as u64
        }
    }
    fn mul_mod(self, rhs: &Self, modulo: &Self) -> Self {
        if *modulo != 0 {
            ((u128::from(self) * u128::from(*rhs)) % u128::from(*modulo)) as u64
        } else {
            (u128::from(self) * u128::from(*rhs)) as u64
        }
    }
}