all basic arith ops done (we don't talk about div)

src/convert.rs

@@ -130,7 +130,14 @@ impl From<SmallUint> for SmallInt {
         match s.0 {
             SmallUintType::Inline(i) => SmallInt::from(i),
             SmallUintType::Heap((r, s)) => {
-                SmallInt(SmallIntType::Heap((r, isize::try_from(s).unwrap())))
+                let slice = unsafe { core::slice::from_raw_parts(r, s) };
+                let mut ret = vec![0; s];
+                ret.clone_from_slice(slice);
+                let mut val = ManuallyDrop::new(ret.into_boxed_slice());
+                SmallInt(SmallIntType::Heap((
+                    val.as_mut_ptr(),
+                    isize::try_from(s).unwrap(),
+                )))
             }
         }
     }
@@ -145,7 +152,11 @@ impl TryFrom<SmallInt> for SmallUint {
             SmallIntType::Heap((r, s)) => {
                 let size = usize::try_from(s).map_err(|_| SmallIntError::ConversionError)?;
                 if size > 4 {
-                    Ok(Self(SmallUintType::Heap((r, size))))
+                    let slice = unsafe { core::slice::from_raw_parts(r, size) };
+                    let mut ret = vec![0; size];
+                    ret.clone_from_slice(slice);
+                    let mut val = ManuallyDrop::new(ret.into_boxed_slice());
+                    Ok(Self(SmallUintType::Heap((val.as_mut_ptr(), size))))
                 } else {
                     Ok(Self(SmallUintType::Inline(u128::try_from(value)?)))
                 }

src/ops.rs

@@ -277,6 +277,12 @@ fn sub(a: &SmallUint, b: &SmallUint) -> SmallUint {
 
 basic_op!(Sub, sub, SmallUint, sub);
 
+fn sub_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
+    a + (-b.clone())
+}
+
+basic_op!(Sub, sub, SmallInt, sub_signed);
+
 // Taken from https://github.com/rust-lang/rust/issues/85532#issuecomment-916309635. Credit to
 // AaronKutch.
 const fn carrying_mul_u128(lhs: u128, rhs: u128, carry: u128) -> (u128, u128) {
@@ -461,3 +467,44 @@ fn mul(a: &SmallUint, b: &SmallUint) -> SmallUint {
 }
 
 basic_op!(Mul, mul, SmallUint, mul);
+
+fn mul_signed(a: &SmallInt, b: &SmallInt) -> SmallInt {
+    let a_sign;
+    match &a.0 {
+        SmallIntType::Inline(i) => a_sign = i.signum() as i8,
+        SmallIntType::Heap((_, s)) => a_sign = s.signum() as i8,
+    }
+
+    let b_sign;
+    match &b.0 {
+        SmallIntType::Inline(i) => b_sign = i.signum() as i8,
+        SmallIntType::Heap((_, s)) => b_sign = s.signum() as i8,
+    }
+
+    match (a_sign, b_sign) {
+        x if (x.0 >= 0 && x.1 >= 0) => SmallInt::from(
+            SmallUint::from_smallint_unsigned(a.clone())
+                * SmallUint::from_smallint_unsigned(b.clone()),
+        ),
+        x if (x.0 < 0 && x.1 < 0) => SmallInt::from(
+            SmallUint::from_smallint_unsigned(a.clone())
+                * SmallUint::from_smallint_unsigned(b.clone()),
+        ),
+
+        x if (x.0 >= 0 && x.1 < 0) => -SmallInt::from(
+            SmallUint::from_smallint_unsigned(a.clone())
+                * SmallUint::from_smallint_unsigned(b.clone()),
+        ),
+
+        x if (x.0 < 0 && x.1 >= 0) => -SmallInt::from(
+            SmallUint::from_smallint_unsigned(a.clone())
+                * SmallUint::from_smallint_unsigned(b.clone()),
+        ),
+
+        (_, _) => {
+            panic!("This shouldn't happen. ");
+        }
+    }
+}
+
+basic_op!(Mul, mul, SmallInt, mul_signed);

src/ord.rs

@@ -1,8 +1,96 @@
-use crate::smallint::SmallIntType;
+use crate::smallint::{SmallIntType, SmallUintType};
 use crate::SmallInt;
 use crate::SmallUint;
 use std::cmp::Ordering;
 
+impl PartialEq for SmallUint {
+    fn eq(&self, other: &SmallUint) -> bool {
+        match (&self.0, &other.0) {
+            (SmallUintType::Inline(i), SmallUintType::Inline(j)) => i.eq(j),
+            (SmallUintType::Heap((r, s)), SmallUintType::Heap((i, j))) => match j.cmp(s) {
+                Ordering::Greater => false,
+                Ordering::Less => false,
+                Ordering::Equal => {
+                    let slice1 = unsafe { core::slice::from_raw_parts(r, *s) };
+                    let slice2 = unsafe { core::slice::from_raw_parts(i, *j) };
+                    for i in 0..*s {
+                        match slice1[s - 1 - i].cmp(&slice2[s - 1 - i]) {
+                            Ordering::Less => return false,
+                            Ordering::Greater => return false,
+                            _ => {}
+                        }
+                    }
+                    true
+                }
+            },
+            (_, _) => false,
+        }
+    }
+}
+
+impl Eq for SmallUint {}
+
+impl PartialOrd for SmallUint {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        match (&self.0, &other.0) {
+            (SmallUintType::Inline(i), SmallUintType::Inline(j)) => Some(i.cmp(j)),
+            (SmallUintType::Inline(_), SmallUintType::Heap((_, _))) => Some(Ordering::Less),
+            (SmallUintType::Heap((_, _)), SmallUintType::Inline(_)) => Some(Ordering::Greater),
+            (SmallUintType::Heap((r, s)), SmallUintType::Heap((i, j))) => match j.cmp(s) {
+                Ordering::Greater => Some(Ordering::Less),
+                Ordering::Less => Some(Ordering::Greater),
+                Ordering::Equal => {
+                    let slice1 = unsafe { core::slice::from_raw_parts(r, *s) };
+                    let slice2 = unsafe { core::slice::from_raw_parts(i, *j) };
+                    for i in 0..*s {
+                        match slice1[s - 1 - i].cmp(&slice2[s - 1 - i]) {
+                            Ordering::Less => return Some(Ordering::Less),
+                            Ordering::Greater => return Some(Ordering::Greater),
+                            _ => {}
+                        }
+                    }
+                    Some(Ordering::Equal)
+                }
+            },
+        }
+    }
+}
+
+impl PartialEq for SmallInt {
+    fn eq(&self, other: &Self) -> bool {
+        match (&self.0, &other.0) {
+            (SmallIntType::Inline(i), SmallIntType::Inline(j)) => i.eq(j),
+            (SmallIntType::Heap((r, s)), SmallIntType::Heap((i, j))) => {
+                if s.signum() != j.signum() {
+                    return false;
+                }
+
+                match j.cmp(s) {
+                    Ordering::Greater => false,
+                    Ordering::Less => false,
+                    Ordering::Equal => {
+                        let us = usize::try_from(s.abs()).unwrap();
+                        let uj = usize::try_from(j.abs()).unwrap();
+                        let slice1 = unsafe { core::slice::from_raw_parts(r, us) };
+                        let slice2 = unsafe { core::slice::from_raw_parts(i, uj) };
+                        for i in 0..*s {
+                            match slice1[(s - 1 - i) as usize].cmp(&slice2[(s - 1 - i) as usize]) {
+                                Ordering::Less => return false,
+                                Ordering::Greater => return false,
+                                _ => {}
+                            }
+                        }
+                        true
+                    }
+                }
+            }
+            (_, _) => false,
+        }
+    }
+}
+
+impl Eq for SmallInt {}
+
 impl PartialOrd for SmallInt {
     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
         let a_sign;

src/smallint.rs

@@ -1,20 +1,18 @@
+use core::mem::ManuallyDrop;
+
 /// An integer-like type that will store small integers up to `i128` inline. Larger integers are
 /// represented as a slice to a sequence of base 2<sup>32</sup> digits represented as a `*mut u32`.
-#[derive(Clone, PartialEq, Eq)]
 pub struct SmallInt(pub(crate) SmallIntType);
 
 /// An integer-like type that will store small integers up to `u128` inline. Larger integers are
 /// represented as a slice to a sequence of base 2<sup>32</sup> digits represented as a `*mut u32`.
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub struct SmallUint(pub(crate) SmallUintType);
 
-#[derive(Clone, PartialEq, Eq)]
 pub enum SmallIntType {
     Inline(i128),
     Heap((*mut u32, isize)),
 }
 
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub enum SmallUintType {
     Inline(u128),
     Heap((*mut u32, usize)),
@@ -38,3 +36,34 @@ impl Drop for SmallUint {
         }
     }
 }
+
+impl Clone for SmallUint {
+    fn clone(&self) -> Self {
+        match self.0 {
+            SmallUintType::Inline(i) => Self(SmallUintType::Inline(i)),
+            SmallUintType::Heap((r, s)) => {
+                let slice = unsafe { core::slice::from_raw_parts(r, s) };
+                let mut ret = vec![0; s];
+                ret.clone_from_slice(slice);
+                let mut val = ManuallyDrop::new(ret.into_boxed_slice());
+                SmallUint(SmallUintType::Heap((val.as_mut_ptr(), s)))
+            }
+        }
+    }
+}
+
+impl Clone for SmallInt {
+    fn clone(&self) -> Self {
+        match self.0 {
+            SmallIntType::Inline(i) => Self(SmallIntType::Inline(i)),
+            SmallIntType::Heap((r, s)) => {
+                let size = usize::try_from(s.abs()).unwrap();
+                let slice = unsafe { core::slice::from_raw_parts(r, size) };
+                let mut ret = vec![0; size];
+                ret.clone_from_slice(slice);
+                let mut val = ManuallyDrop::new(ret.into_boxed_slice());
+                SmallInt(SmallIntType::Heap((val.as_mut_ptr(), s)))
+            }
+        }
+    }
+}

src/tests.rs

@@ -34,7 +34,51 @@ conversion_tests!(i128, test_i128);
 
 #[test]
 #[cfg(feature = "num-bigint")]
-fn test_op_add_u_u() {
+fn test_cmp_u() {
+    let i = SmallUint::from(30u32);
+    let k = SmallUint::from(50u32);
+    assert!(i < k);
+
+    let i = SmallUint::from(u128::MAX);
+    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
+    assert!(i < k);
+
+    let i = SmallUint::from(&BigUint::new(vec![3, 9, 8, 3, 1]));
+    let k = SmallUint::from(&BigUint::new(vec![5, 4, 9, 3, 1, 81]));
+    assert!(i < k);
+}
+
+#[test]
+#[cfg(feature = "num-bigint")]
+fn test_cmp_i() {
+    let i = SmallInt::from(30u32);
+    let k = SmallInt::from(50u32);
+    assert!(i < k);
+
+    let i = SmallInt::from(u128::MAX);
+    let k = SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
+    assert!(i < k);
+
+    let i = SmallInt::from(&BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1]));
+    let k = SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
+    assert!(i < k);
+
+    let i = SmallInt::from(30u32);
+    let k = -SmallInt::from(50u32);
+    assert!(k < i);
+
+    let i = SmallInt::from(u128::MAX);
+    let k = -SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
+    assert!(k < i);
+
+    let i = SmallInt::from(&BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1]));
+    let k = -SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
+    assert!(k < i);
+}
+
+#[test]
+#[cfg(feature = "num-bigint")]
+fn test_op_add_u() {
     let i = SmallUint::from(u128::MAX);
     let k = SmallUint::from(u128::MAX);
     let q = i + k;
@@ -59,7 +103,33 @@ fn test_op_add_u_u() {
 
 #[test]
 #[cfg(feature = "num-bigint")]
-fn test_op_mul_u_u() {
+fn test_op_add_i() {
+    let i = SmallInt::from(u128::MAX);
+    let k = -SmallInt::from(u128::MAX);
+    let q = i + k;
+    assert_eq!(BigInt::from(&q), BigInt::from(0));
+
+    let i = SmallInt::from(u128::MAX);
+    let k = -SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
+    let q = i + k;
+    assert_eq!(
+        BigInt::from(&q),
+        u128::MAX - BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81])
+    );
+
+    let i = -SmallInt::from(&BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1]));
+    let k = SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
+    let q = i + k;
+    assert_eq!(
+        BigInt::from(&q),
+        BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81])
+            - BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1])
+    );
+}
+
+#[test]
+#[cfg(feature = "num-bigint")]
+fn test_op_mul_u() {
     let i = SmallUint::from(u128::MAX);
     let k = SmallUint::from(u128::MAX);
     let q = i * k;
@@ -84,7 +154,33 @@ fn test_op_mul_u_u() {
 
 #[test]
 #[cfg(feature = "num-bigint")]
-fn test_op_sub_u_u() {
+fn test_op_mul_i() {
+    let i = -SmallInt::from(u128::MAX);
+    let k = SmallInt::from(u128::MAX);
+    let q = i * k;
+    assert_eq!(BigInt::from(&q), -BigInt::from(u128::MAX) * u128::MAX);
+
+    let i = -SmallInt::from(u32::MAX);
+    let k = -SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
+    let q = i * k;
+    assert_eq!(
+        BigInt::from(&q),
+        BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]) * u32::MAX
+    );
+
+    let i = -SmallInt::from(&BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1]));
+    let k = SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
+    let q = i * k;
+    assert_eq!(
+        BigInt::from(&q),
+        BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1])
+            * -BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81])
+    );
+}
+
+#[test]
+#[cfg(feature = "num-bigint")]
+fn test_op_sub_u() {
     let i = SmallUint::from(u128::MAX);
     let k = SmallUint::from(u128::MAX);
     let q = i - k;
@@ -109,7 +205,33 @@ fn test_op_sub_u_u() {
 
 #[test]
 #[cfg(feature = "num-bigint")]
-fn test_op_and_u_u() {
+fn test_op_sub_i() {
+    let i = -SmallInt::from(u128::MAX);
+    let k = SmallInt::from(u128::MAX);
+    let q = i - k;
+    assert_eq!(BigInt::from(&q), -BigInt::from(u128::MAX) - u128::MAX);
+
+    let k = SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
+    let i = -SmallInt::from(u128::MAX);
+    let q = k - i;
+    assert_eq!(
+        BigInt::from(&q),
+        BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]) + u128::MAX
+    );
+
+    let k = -SmallInt::from(&BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81]));
+    let i = SmallInt::from(&BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1]));
+    let q = k - i;
+    assert_eq!(
+        BigInt::from(&q),
+        -(BigInt::new(Sign::Plus, vec![5, 4, 9, 3, 1, 81])
+            + BigInt::new(Sign::Plus, vec![3, 9, 8, 3, 1]))
+    );
+}
+
+#[test]
+#[cfg(feature = "num-bigint")]
+fn test_op_and_u() {
     let i = SmallUint::from(u128::MAX);
     let k = SmallUint::from(u128::MAX);
     let q = i & k;
@@ -137,7 +259,7 @@ fn test_op_and_u_u() {
 
 #[test]
 #[cfg(feature = "num-bigint")]
-fn test_op_or_u_u() {
+fn test_op_or_u() {
     let i = SmallUint::from(u128::MAX);
     let k = SmallUint::from(u128::MAX);
     let q = i | k;
@@ -165,7 +287,7 @@ fn test_op_or_u_u() {
 
 #[test]
 #[cfg(feature = "num-bigint")]
-fn test_op_xor_u_u() {
+fn test_op_xor_u() {
     let i = SmallUint::from(u128::MAX);
     let k = SmallUint::from(u128::MAX);
     let q = i ^ k;