update

mathx/int.go

@@ -1,35 +0,0 @@
-package mathx
-
-import (
-	"github.com/charlienet/go-mixed/expr"
-	"golang.org/x/exp/constraints"
-	"unsafe"
-)
-
-// Max returns the larger one of v1 and v2.
-func Max[T constraints.Ordered](v1, v2 T) T {
-	return expr.Ternary(v1 > v2, v1, v2)
-}
-
-// Min returns the smaller one of v1 and v2.
-func Min[T constraints.Ordered](v1, v2 T) T {
-	return expr.Ternary(v1 < v2, v1, v2)
-}
-
-func Abs1[T constraints.Signed](n T) T {
-	shift := 63
-	switch unsafe.Sizeof(n) {
-	case 1:
-		shift = 7
-	case 4:
-		shift = 31
-	}
-
-	y := n >> shift
-	return T((n ^ y) - y)
-}
-
-func Abs(n int64) int64 {
-	y := n >> 63
-	return (n ^ y) - y
-}

mathx/int_test.go

@@ -1,27 +0,0 @@
-package mathx_test
-
-import (
-	"github.com/charlienet/go-mixed/mathx"
-	"github.com/stretchr/testify/assert"
-	"testing"
-)
-
-func TestMin(t *testing.T) {
-	assert.Equal(t, 1, mathx.Min(1, 3))
-	assert.Equal(t, 2, mathx.Min(66, 2))
-}
-
-func TestMax(t *testing.T) {
-	assert.Equal(t, 3, mathx.Max(1, 3))
-	assert.Equal(t, 66, mathx.Max(66, 2))
-}
-
-func TestAbs(t *testing.T) {
-	assert.Equal(t, 23, mathx.Abs1(23))
-	assert.Equal(t, 23, mathx.Abs1(-23))
-	assert.Equal(t, 0, mathx.Abs1(0))
-
-	var u int8 = -127
-	var exp int8 = 127
-	assert.Equal(t, exp, mathx.Abs1(u))
-}

mathx/math.go

@@ -0,0 +1,46 @@
+package mathx
+
+import (
+	"github.com/charlienet/go-mixed/expr"
+	"golang.org/x/exp/constraints"
+)
+
+type Real interface {
+	constraints.Integer | constraints.Float
+}
+
+// Max returns the larger one of v1 and v2.
+func Max[T Real](v1, v2 T) T {
+	return expr.Ternary(v1 > v2, v1, v2)
+}
+
+// Min returns the smaller one of v1 and v2.
+func Min[T Real](v1, v2 T) T {
+	return expr.Ternary(v1 < v2, v1, v2)
+}
+
+func Abs[T Real](val T) T {
+	return expr.Ternary(val < 0, -val, val)
+}
+
+// Neg returns the negative of value. It does not negate value. For
+// negating, simply use -value instead.
+func Neg[T Real](value T) T {
+	return expr.Ternary(value < 0, value, -value)
+}
+
+func Clamp[T Real](value, min, max T) T {
+	if min > max {
+		return min
+	}
+
+	if value < min {
+		return min
+	}
+
+	if value > max {
+		return max
+	}
+
+	return value
+}

mathx/math_test.go

@@ -0,0 +1,54 @@
+package mathx_test
+
+import (
+	"testing"
+
+	"github.com/charlienet/go-mixed/mathx"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMin(t *testing.T) {
+	assert.Equal(t, 1, mathx.Min(1, 3))
+	assert.Equal(t, 2, mathx.Min(66, 2))
+}
+
+func TestMax(t *testing.T) {
+	assert.Equal(t, 3, mathx.Max(1, 3))
+	assert.Equal(t, 66, mathx.Max(66, 2))
+}
+
+func TestAbs(t *testing.T) {
+	assert.Equal(t, 23, mathx.Abs(23))
+	assert.Equal(t, 23, mathx.Abs(-23))
+	assert.Equal(t, 0, mathx.Abs(0))
+
+	var u int8 = -127
+	var exp int8 = 127
+	assert.Equal(t, exp, mathx.Abs(u))
+
+	assert.Equal(t, 1.23, mathx.Abs(-1.23))
+}
+
+func TestClamp(t *testing.T) {
+	tests := []struct{ value, min, max, want int }{
+		// Min.
+		{-1, 0, 2, 0},
+		{0, 0, 2, 0},
+		// Mid.
+		{1, 0, 2, 1},
+		{2, 0, 2, 2},
+		// Max.
+		{2, 0, 2, 2},
+		{3, 0, 2, 2},
+		// Empty range.
+		{-1, 0, 0, 0},
+		{0, 0, 0, 0},
+		{1, 0, 0, 0},
+	}
+	for _, test := range tests {
+		got := mathx.Clamp(test.value, test.min, test.max)
+		if got != test.want {
+			t.Errorf("Clamp(%v, %v, %v) = %v, want %v", test.value, test.min, test.max, got, test.want)
+		}
+	}
+}