Add math.Max and math.Min

Closes #8583
This commit is contained in:
Joe Mooring 2021-05-27 08:34:49 -07:00 committed by Bjørn Erik Pedersen
parent 845a7ba4fc
commit 01758f99b9
4 changed files with 129 additions and 12 deletions

View file

@ -1,6 +1,6 @@
---
title: Math
description: Hugo provides nine mathematical operators in templates.
description: Hugo provides mathematical operators in templates.
godocref:
date: 2017-02-01
publishdate: 2017-02-01
@ -35,7 +35,9 @@ aliases: []
| `modBool` | Boolean of modulus of two integers. Evaluates to `true` if result equals 0. | `{{modBool 15 3}}` → `true` |
| `math.Ceil` | Returns the least integer value greater than or equal to the given number. | `{{math.Ceil 2.1}}` → `3` |
| `math.Floor` | Returns the greatest integer value less than or equal to the given number. | `{{math.Floor 1.9}}` → `1` |
| `math.Round` | Returns the nearest integer, rounding half away from zero. | `{{math.Round 1.5}}` → `2` |
| `math.Log` | Returns the natural logarithm of the given number. | `{{math.Log 42}}` → `3.737` |
| `math.Sqrt` | Returns the square root of the given number. | `{{math.Sqrt 81}}` → `9` |
| `math.Max` | Returns the greater of two numbers. | `{{math.Max 1 2}}` → `2` |
| `math.Min` | Returns the smaller of two numbers. | `{{math.Min 1 2}}` → `1` |
| `math.Pow` | Returns the first number raised to the power of the second number. | `{{math.Pow 2 3}}` → `8` |
| `math.Round` | Returns the nearest integer, rounding half away from zero. | `{{math.Round 1.5}}` → `2` |
| `math.Sqrt` | Returns the square root of the given number. | `{{math.Sqrt 81}}` → `9` |

View file

@ -64,10 +64,17 @@ func init() {
},
)
ns.AddMethodMapping(ctx.Sqrt,
ns.AddMethodMapping(ctx.Max,
nil,
[][2]string{
{"{{math.Sqrt 81}}", "9"},
{"{{math.Max 1 2 }}", "2"},
},
)
ns.AddMethodMapping(ctx.Min,
nil,
[][2]string{
{"{{math.Min 1 2 }}", "1"},
},
)
@ -106,6 +113,13 @@ func init() {
},
)
ns.AddMethodMapping(ctx.Sqrt,
nil,
[][2]string{
{"{{math.Sqrt 81}}", "9"},
},
)
ns.AddMethodMapping(ctx.Sub,
[]string{"sub"},
[][2]string{

View file

@ -71,15 +71,28 @@ func (ns *Namespace) Log(a interface{}) (float64, error) {
return math.Log(af), nil
}
// Sqrt returns the square root of a number.
// NOTE: will return for NaN for negative values of a
func (ns *Namespace) Sqrt(a interface{}) (float64, error) {
af, err := cast.ToFloat64E(a)
if err != nil {
return 0, errors.New("Sqrt operator can't be used with non integer or float value")
// Max returns the greater of two numbers.
func (ns *Namespace) Max(a, b interface{}) (float64, error) {
af, erra := cast.ToFloat64E(a)
bf, errb := cast.ToFloat64E(b)
if erra != nil || errb != nil {
return 0, errors.New("Max operator can't be used with non-float value")
}
return math.Sqrt(af), nil
return math.Max(af, bf), nil
}
// Min returns the smaller of two numbers.
func (ns *Namespace) Min(a, b interface{}) (float64, error) {
af, erra := cast.ToFloat64E(a)
bf, errb := cast.ToFloat64E(b)
if erra != nil || errb != nil {
return 0, errors.New("Min operator can't be used with non-float value")
}
return math.Min(af, bf), nil
}
// Mod returns a % b.
@ -135,6 +148,16 @@ func (ns *Namespace) Round(x interface{}) (float64, error) {
return _round(xf), nil
}
// Sqrt returns the square root of a number.
func (ns *Namespace) Sqrt(a interface{}) (float64, error) {
af, err := cast.ToFloat64E(a)
if err != nil {
return 0, errors.New("Sqrt operator can't be used with non integer or float value")
}
return math.Sqrt(af), nil
}
// Sub subtracts two numbers.
func (ns *Namespace) Sub(a, b interface{}) (interface{}, error) {
return _math.DoArithmetic(a, b, '-')

View file

@ -357,3 +357,81 @@ func TestPow(t *testing.T) {
c.Assert(result, qt.Equals, test.expect)
}
}
func TestMax(t *testing.T) {
t.Parallel()
c := qt.New(t)
ns := New()
for _, test := range []struct {
a interface{}
b interface{}
expect interface{}
}{
{-1, -1, float64(-1)},
{-1, 0, float64(0)},
{-1, 1, float64(1)},
{0, -1, float64(0)},
{0, 0, float64(0)},
{0, 1, float64(1)},
{1, -1, float64(1)},
{1, 0, float64(1)},
{1, 1, float64(1)},
{1.2, 1.23, float64(1.23)},
{-1.2, -1.23, float64(-1.2)},
{0, "a", false},
{"a", 0, false},
{"a", "b", false},
} {
result, err := ns.Max(test.a, test.b)
if b, ok := test.expect.(bool); ok && !b {
c.Assert(err, qt.Not(qt.IsNil))
continue
}
c.Assert(err, qt.IsNil)
c.Assert(result, qt.Equals, test.expect)
}
}
func TestMin(t *testing.T) {
t.Parallel()
c := qt.New(t)
ns := New()
for _, test := range []struct {
a interface{}
b interface{}
expect interface{}
}{
{-1, -1, float64(-1)},
{-1, 0, float64(-1)},
{-1, 1, float64(-1)},
{0, -1, float64(-1)},
{0, 0, float64(0)},
{0, 1, float64(0)},
{1, -1, float64(-1)},
{1, 0, float64(0)},
{1, 1, float64(1)},
{1.2, 1.23, float64(1.2)},
{-1.2, -1.23, float64(-1.23)},
{0, "a", false},
{"a", 0, false},
{"a", "b", false},
} {
result, err := ns.Min(test.a, test.b)
if b, ok := test.expect.(bool); ok && !b {
c.Assert(err, qt.Not(qt.IsNil))
continue
}
c.Assert(err, qt.IsNil)
c.Assert(result, qt.Equals, test.expect)
}
}