1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
// Copyright 2017 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package math
import (
"errors"
"math"
"reflect"
"github.com/spf13/cast"
)
// New returns a new instance of the math-namespaced template functions.
func New() *Namespace {
return &Namespace{}
}
// Namespace provides template functions for the "math" namespace.
type Namespace struct{}
// Add adds two numbers.
func (ns *Namespace) Add(a, b interface{}) (interface{}, error) {
return DoArithmetic(a, b, '+')
}
// Ceil returns the least integer value greater than or equal to x.
func (ns *Namespace) Ceil(x interface{}) (float64, error) {
xf, err := cast.ToFloat64E(x)
if err != nil {
return 0, errors.New("Ceil operator can't be used with non-float value")
}
return math.Ceil(xf), nil
}
// Div divides two numbers.
func (ns *Namespace) Div(a, b interface{}) (interface{}, error) {
return DoArithmetic(a, b, '/')
}
// Floor returns the greatest integer value less than or equal to x.
func (ns *Namespace) Floor(x interface{}) (float64, error) {
xf, err := cast.ToFloat64E(x)
if err != nil {
return 0, errors.New("Floor operator can't be used with non-float value")
}
return math.Floor(xf), nil
}
// Log returns the natural logarithm of a number.
func (ns *Namespace) Log(a interface{}) (float64, error) {
af, err := cast.ToFloat64E(a)
if err != nil {
return 0, errors.New("Log operator can't be used with non integer or float value")
}
return math.Log(af), nil
}
// Mod returns a % b.
func (ns *Namespace) Mod(a, b interface{}) (int64, error) {
ai, erra := cast.ToInt64E(a)
bi, errb := cast.ToInt64E(b)
if erra != nil || errb != nil {
return 0, errors.New("Modulo operator can't be used with non integer value")
}
if bi == 0 {
return 0, errors.New("The number can't be divided by zero at modulo operation")
}
return ai % bi, nil
}
// ModBool returns the boolean of a % b. If a % b == 0, return true.
func (ns *Namespace) ModBool(a, b interface{}) (bool, error) {
res, err := ns.Mod(a, b)
if err != nil {
return false, err
}
return res == int64(0), nil
}
// Mul multiplies two numbers.
func (ns *Namespace) Mul(a, b interface{}) (interface{}, error) {
return DoArithmetic(a, b, '*')
}
// Round returns the nearest integer, rounding half away from zero.
func (ns *Namespace) Round(x interface{}) (float64, error) {
xf, err := cast.ToFloat64E(x)
if err != nil {
return 0, errors.New("Round operator can't be used with non-float value")
}
return _round(xf), nil
}
// Sub subtracts two numbers.
func (ns *Namespace) Sub(a, b interface{}) (interface{}, error) {
return DoArithmetic(a, b, '-')
}
// DoArithmetic performs arithmetic operations (+,-,*,/) using reflection to
// determine the type of the two terms.
func DoArithmetic(a, b interface{}, op rune) (interface{}, error) {
av := reflect.ValueOf(a)
bv := reflect.ValueOf(b)
var ai, bi int64
var af, bf float64
var au, bu uint64
switch av.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
ai = av.Int()
switch bv.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
bi = bv.Int()
case reflect.Float32, reflect.Float64:
af = float64(ai) // may overflow
ai = 0
bf = bv.Float()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
bu = bv.Uint()
if ai >= 0 {
au = uint64(ai)
ai = 0
} else {
bi = int64(bu) // may overflow
bu = 0
}
default:
return nil, errors.New("Can't apply the operator to the values")
}
case reflect.Float32, reflect.Float64:
af = av.Float()
switch bv.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
bf = float64(bv.Int()) // may overflow
case reflect.Float32, reflect.Float64:
bf = bv.Float()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
bf = float64(bv.Uint()) // may overflow
default:
return nil, errors.New("Can't apply the operator to the values")
}
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
au = av.Uint()
switch bv.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
bi = bv.Int()
if bi >= 0 {
bu = uint64(bi)
bi = 0
} else {
ai = int64(au) // may overflow
au = 0
}
case reflect.Float32, reflect.Float64:
af = float64(au) // may overflow
au = 0
bf = bv.Float()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
bu = bv.Uint()
default:
return nil, errors.New("Can't apply the operator to the values")
}
case reflect.String:
as := av.String()
if bv.Kind() ==
|
