Commit 5acc8afb5f

@@ -534,13 +534,14 @@ pub const Int = struct {
         return out_stream.writeAll(str);
     }
 
-    /// Returns -1, 0, 1 if |a| < |b|, |a| == |b| or |a| > |b| respectively.
-    pub fn cmpAbs(a: Int, b: Int) i8 {
+    /// Returns math.Order.lt, math.Order.eq, math.Order.gt if |a| < |b|, |a| ==
+    /// |b| or |a| > |b| respectively.
+    pub fn cmpAbs(a: Int, b: Int) math.Order {
         if (a.len() < b.len()) {
-            return -1;
+            return .lt;
         }
         if (a.len() > b.len()) {
-            return 1;
+            return .gt;
         }
 
         var i: usize = a.len() - 1;
@@ -551,21 +552,26 @@ pub const Int = struct {
         }
 
         if (a.limbs[i] < b.limbs[i]) {
-            return -1;
+            return .lt;
         } else if (a.limbs[i] > b.limbs[i]) {
-            return 1;
+            return .gt;
         } else {
-            return 0;
+            return .eq;
         }
     }
 
-    /// Returns -1, 0, 1 if a < b, a == b or a > b respectively.
-    pub fn cmp(a: Int, b: Int) i8 {
+    /// Returns math.Order.lt, math.Order.eq, math.Order.gt if a < b, a == b or a
+    /// > b respectively.
+    pub fn cmp(a: Int, b: Int) math.Order {
         if (a.isPositive() != b.isPositive()) {
-            return if (a.isPositive()) @as(i8, 1) else -1;
+            return if (a.isPositive()) .gt else .lt;
         } else {
             const r = cmpAbs(a, b);
-            return if (a.isPositive()) r else -r;
+            return if (a.isPositive()) r else switch (r) {
+                .lt => math.Order.gt,
+                .eq => math.Order.eq,
+                .gt => math.Order.lt,
+            };
         }
     }
 
@@ -576,12 +582,12 @@ pub const Int = struct {
 
     /// Returns true if |a| == |b|.
     pub fn eqAbs(a: Int, b: Int) bool {
-        return cmpAbs(a, b) == 0;
+        return cmpAbs(a, b) == .eq;
     }
 
     /// Returns true if a == b.
     pub fn eq(a: Int, b: Int) bool {
-        return cmp(a, b) == 0;
+        return cmp(a, b) == .eq;
     }
 
     // Normalize a possible sequence of leading zeros.
@@ -694,7 +700,7 @@ pub const Int = struct {
         } else {
             if (a.isPositive()) {
                 // (a) - (b) => a - b
-                if (a.cmp(b) >= 0) {
+                if (a.cmp(b) != .lt) {
                     try r.ensureCapacity(a.len() + 1);
                     llsub(r.limbs[0..], a.limbs[0..a.len()], b.limbs[0..b.len()]);
                     r.normalize(a.len());
@@ -707,7 +713,7 @@ pub const Int = struct {
                 }
             } else {
                 // (-a) - (-b) => -(a - b)
-                if (a.cmp(b) < 0) {
+                if (a.cmp(b) == .lt) {
                     try r.ensureCapacity(a.len() + 1);
                     llsub(r.limbs[0..], a.limbs[0..a.len()], b.limbs[0..b.len()]);
                     r.normalize(a.len());
@@ -1010,7 +1016,7 @@ pub const Int = struct {
             @panic("quo and rem cannot be same variable");
         }
 
-        if (a.cmpAbs(b) < 0) {
+        if (a.cmpAbs(b) == .lt) {
             // quo may alias a so handle rem first
             try rem.copy(a);
             rem.setSign(a.isPositive() == b.isPositive());
@@ -1133,7 +1139,7 @@ pub const Int = struct {
 
         // 2.
         try tmp.shiftLeft(y.*, Limb.bit_count * (n - t));
-        while (x.cmp(tmp) >= 0) {
+        while (x.cmp(tmp) != .lt) {
             q.limbs[n - t] += 1;
             try x.sub(x.*, tmp);
         }
@@ -1164,7 +1170,7 @@ pub const Int = struct {
                 r.limbs[2] = carry;
                 r.normalize(3);
 
-                if (r.cmpAbs(tmp) <= 0) {
+                if (r.cmpAbs(tmp) != .gt) {
                     break;
                 }
 
@@ -1719,8 +1725,8 @@ test "big.int compare" {
     var b = try Int.initSet(testing.allocator, 10);
     defer b.deinit();
 
-    testing.expect(a.cmpAbs(b) == 1);
-    testing.expect(a.cmp(b) == -1);
+    testing.expect(a.cmpAbs(b) == .gt);
+    testing.expect(a.cmp(b) == .lt);
 }
 
 test "big.int compare similar" {
@@ -1729,8 +1735,8 @@ test "big.int compare similar" {
     var b = try Int.initSet(testing.allocator, 0xffffffffeeeeeeeeffffffffeeeeeeef);
     defer b.deinit();
 
-    testing.expect(a.cmpAbs(b) == -1);
-    testing.expect(b.cmpAbs(a) == 1);
+    testing.expect(a.cmpAbs(b) == .lt);
+    testing.expect(b.cmpAbs(a) == .gt);
 }
 
 test "big.int compare different limb size" {
@@ -1739,8 +1745,8 @@ test "big.int compare different limb size" {
     var b = try Int.initSet(testing.allocator, 1);
     defer b.deinit();
 
-    testing.expect(a.cmpAbs(b) == 1);
-    testing.expect(b.cmpAbs(a) == -1);
+    testing.expect(a.cmpAbs(b) == .gt);
+    testing.expect(b.cmpAbs(a) == .lt);
 }
 
 test "big.int compare multi-limb" {
@@ -1749,8 +1755,8 @@ test "big.int compare multi-limb" {
     var b = try Int.initSet(testing.allocator, 0x7777777799999999ffffeeeeffffeeeeffffeeeee);
     defer b.deinit();
 
-    testing.expect(a.cmpAbs(b) == 1);
-    testing.expect(a.cmp(b) == -1);
+    testing.expect(a.cmpAbs(b) == .gt);
+    testing.expect(a.cmp(b) == .lt);
 }
 
 test "big.int equality" {
@@ -2726,9 +2732,9 @@ test "big.int var args" {
 
     const c = try Int.initSet(testing.allocator, 11);
     defer c.deinit();
-    testing.expect(a.cmp(c) == 0);
+    testing.expect(a.cmp(c) == .eq);
 
     const d = try Int.initSet(testing.allocator, 14);
     defer d.deinit();
-    testing.expect(a.cmp(d) <= 0);
+    testing.expect(a.cmp(d) != .gt);
 }

@@ -326,18 +326,20 @@ pub const Rational = struct {
         r.q.swap(&other.q);
     }
 
-    /// Returns -1, 0, 1 if a < b, a == b or a > b respectively.
-    pub fn cmp(a: Rational, b: Rational) !i8 {
+    /// Returns math.Order.lt, math.Order.eq, math.Order.gt if a < b, a == b or a
+    /// > b respectively.
+    pub fn cmp(a: Rational, b: Rational) !math.Order {
         return cmpInternal(a, b, true);
     }
 
-    /// Returns -1, 0, 1 if |a| < |b|, |a| == |b| or |a| > |b| respectively.
-    pub fn cmpAbs(a: Rational, b: Rational) !i8 {
+    /// Returns math.Order.lt, math.Order.eq, math.Order.gt if |a| < |b|, |a| ==
+    /// |b| or |a| > |b| respectively.
+    pub fn cmpAbs(a: Rational, b: Rational) !math.Order {
         return cmpInternal(a, b, false);
     }
 
     // p/q > x/y iff p*y > x*q
-    fn cmpInternal(a: Rational, b: Rational, is_abs: bool) !i8 {
+    fn cmpInternal(a: Rational, b: Rational, is_abs: bool) !math.Order {
         // TODO: Would a div compare algorithm of sorts be viable and quicker? Can we avoid
         // the memory allocations here?
         var q = try Int.init(a.p.allocator.?);
@@ -450,7 +452,7 @@ pub const Rational = struct {
         r.p.setSign(sign);
 
         const one = Int.initFixed(([_]Limb{1})[0..]);
-        if (a.cmp(one) != 0) {
+        if (a.cmp(one) != .eq) {
             var unused = try Int.init(r.p.allocator.?);
             defer unused.deinit();
 
@@ -505,7 +507,7 @@ fn gcdLehmer(r: *Int, xa: Int, ya: Int) !void {
     y.abs();
     defer y.deinit();
 
-    if (x.cmp(y) < 0) {
+    if (x.cmp(y) == .lt) {
         x.swap(&y);
     }
 
@@ -573,7 +575,7 @@ fn gcdLehmer(r: *Int, xa: Int, ya: Int) !void {
     }
 
     // euclidean algorithm
-    debug.assert(x.cmp(y) >= 0);
+    debug.assert(x.cmp(y) != .lt);
 
     while (!y.eqZero()) {
         try Int.divTrunc(&T, r, x, y);
@@ -874,11 +876,11 @@ test "big.rational cmp" {
 
     try a.setRatio(500, 231);
     try b.setRatio(18903, 8584);
-    testing.expect((try a.cmp(b)) < 0);
+    testing.expect((try a.cmp(b)) == .lt);
 
     try a.setRatio(890, 10);
     try b.setRatio(89, 1);
-    testing.expect((try a.cmp(b)) == 0);
+    testing.expect((try a.cmp(b)) == .eq);
 }
 
 test "big.rational add single-limb" {
@@ -889,11 +891,11 @@ test "big.rational add single-limb" {
 
     try a.setRatio(500, 231);
     try b.setRatio(18903, 8584);
-    testing.expect((try a.cmp(b)) < 0);
+    testing.expect((try a.cmp(b)) == .lt);
 
     try a.setRatio(890, 10);
     try b.setRatio(89, 1);
-    testing.expect((try a.cmp(b)) == 0);
+    testing.expect((try a.cmp(b)) == .eq);
 }
 
 test "big.rational add" {
@@ -909,7 +911,7 @@ test "big.rational add" {
     try a.add(a, b);
 
     try r.setRatio(984786924199, 290395044174);
-    testing.expect((try a.cmp(r)) == 0);
+    testing.expect((try a.cmp(r)) == .eq);
 }
 
 test "big.rational sub" {
@@ -925,7 +927,7 @@ test "big.rational sub" {
     try a.sub(a, b);
 
     try r.setRatio(979040510045, 290395044174);
-    testing.expect((try a.cmp(r)) == 0);
+    testing.expect((try a.cmp(r)) == .eq);
 }
 
 test "big.rational mul" {
@@ -941,7 +943,7 @@ test "big.rational mul" {
     try a.mul(a, b);
 
     try r.setRatio(571481443, 17082061422);
-    testing.expect((try a.cmp(r)) == 0);
+    testing.expect((try a.cmp(r)) == .eq);
 }
 
 test "big.rational div" {
@@ -957,7 +959,7 @@ test "big.rational div" {
     try a.div(a, b);
 
     try r.setRatio(75531824394, 221015929);
-    testing.expect((try a.cmp(r)) == 0);
+    testing.expect((try a.cmp(r)) == .eq);
 }
 
 test "big.rational div" {
@@ -970,11 +972,11 @@ test "big.rational div" {
     a.invert();
 
     try r.setRatio(23341, 78923);
-    testing.expect((try a.cmp(r)) == 0);
+    testing.expect((try a.cmp(r)) == .eq);
 
     try a.setRatio(-78923, 23341);
     a.invert();
 
     try r.setRatio(-23341, 78923);
-    testing.expect((try a.cmp(r)) == 0);
+    testing.expect((try a.cmp(r)) == .eq);
 }