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
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
|
package xpath
import (
"fmt"
"reflect"
"strconv"
)
// The XPath number operator function list.
// valueType is a return value type.
type valueType int
const (
booleanType valueType = iota
numberType
stringType
nodeSetType
)
func getValueType(i interface{}) valueType {
v := reflect.ValueOf(i)
switch v.Kind() {
case reflect.Float64:
return numberType
case reflect.String:
return stringType
case reflect.Bool:
return booleanType
default:
if _, ok := i.(query); ok {
return nodeSetType
}
}
panic(fmt.Errorf("xpath unknown value type: %v", v.Kind()))
}
type logical func(iterator, string, interface{}, interface{}) bool
var logicalFuncs = [][]logical{
{cmpBooleanBoolean, nil, nil, nil},
{nil, cmpNumericNumeric, cmpNumericString, cmpNumericNodeSet},
{nil, cmpStringNumeric, cmpStringString, cmpStringNodeSet},
{nil, cmpNodeSetNumeric, cmpNodeSetString, cmpNodeSetNodeSet},
}
// number vs number
func cmpNumberNumberF(op string, a, b float64) bool {
switch op {
case "=":
return a == b
case ">":
return a > b
case "<":
return a < b
case ">=":
return a >= b
case "<=":
return a <= b
case "!=":
return a != b
}
return false
}
// string vs string
func cmpStringStringF(op string, a, b string) bool {
switch op {
case "=":
return a == b
case ">":
return a > b
case "<":
return a < b
case ">=":
return a >= b
case "<=":
return a <= b
case "!=":
return a != b
}
return false
}
func cmpBooleanBooleanF(op string, a, b bool) bool {
switch op {
case "or":
return a || b
case "and":
return a && b
}
return false
}
func cmpNumericNumeric(t iterator, op string, m, n interface{}) bool {
a := m.(float64)
b := n.(float64)
return cmpNumberNumberF(op, a, b)
}
func cmpNumericString(t iterator, op string, m, n interface{}) bool {
a := m.(float64)
b := n.(string)
num, err := strconv.ParseFloat(b, 64)
if err != nil {
panic(err)
}
return cmpNumberNumberF(op, a, num)
}
func cmpNumericNodeSet(t iterator, op string, m, n interface{}) bool {
a := m.(float64)
b := n.(query)
for {
node := b.Select(t)
if node == nil {
break
}
num, err := strconv.ParseFloat(node.Value(), 64)
if err != nil {
panic(err)
}
if cmpNumberNumberF(op, a, num) {
return true
}
}
return false
}
func cmpNodeSetNumeric(t iterator, op string, m, n interface{}) bool {
a := m.(query)
b := n.(float64)
for {
node := a.Select(t)
if node == nil {
break
}
num, err := strconv.ParseFloat(node.Value(), 64)
if err != nil {
panic(err)
}
if cmpNumberNumberF(op, num, b) {
return true
}
}
return false
}
func cmpNodeSetString(t iterator, op string, m, n interface{}) bool {
a := m.(query)
b := n.(string)
for {
node := a.Select(t)
if node == nil {
break
}
if cmpStringStringF(op, b, node.Value()) {
return true
}
}
return false
}
func cmpNodeSetNodeSet(t iterator, op string, m, n interface{}) bool {
return false
}
func cmpStringNumeric(t iterator, op string, m, n interface{}) bool {
a := m.(string)
b := n.(float64)
num, err := strconv.ParseFloat(a, 64)
if err != nil {
panic(err)
}
return cmpNumberNumberF(op, b, num)
}
func cmpStringString(t iterator, op string, m, n interface{}) bool {
a := m.(string)
b := n.(string)
return cmpStringStringF(op, a, b)
}
func cmpStringNodeSet(t iterator, op string, m, n interface{}) bool {
a := m.(string)
b := n.(query)
for {
node := b.Select(t)
if node == nil {
break
}
if cmpStringStringF(op, a, node.Value()) {
return true
}
}
return false
}
func cmpBooleanBoolean(t iterator, op string, m, n interface{}) bool {
a := m.(bool)
b := n.(bool)
return cmpBooleanBooleanF(op, a, b)
}
// eqFunc is an `=` operator.
func eqFunc(t iterator, m, n interface{}) interface{} {
t1 := getValueType(m)
t2 := getValueType(n)
return logicalFuncs[t1][t2](t, "=", m, n)
}
// gtFunc is an `>` operator.
func gtFunc(t iterator, m, n interface{}) interface{} {
t1 := getValueType(m)
t2 := getValueType(n)
return logicalFuncs[t1][t2](t, ">", m, n)
}
// geFunc is an `>=` operator.
func geFunc(t iterator, m, n interface{}) interface{} {
t1 := getValueType(m)
t2 := getValueType(n)
return logicalFuncs[t1][t2](t, ">=", m, n)
}
// ltFunc is an `<` operator.
func ltFunc(t iterator, m, n interface{}) interface{} {
t1 := getValueType(m)
t2 := getValueType(n)
return logicalFuncs[t1][t2](t, "<", m, n)
}
// leFunc is an `<=` operator.
func leFunc(t iterator, m, n interface{}) interface{} {
t1 := getValueType(m)
t2 := getValueType(n)
return logicalFuncs[t1][t2](t, "<=", m, n)
}
// neFunc is an `!=` operator.
func neFunc(t iterator, m, n interface{}) interface{} {
t1 := getValueType(m)
t2 := getValueType(n)
return logicalFuncs[t1][t2](t, "!=", m, n)
}
// orFunc is an `or` operator.
var orFunc = func(t iterator, m, n interface{}) interface{} {
t1 := getValueType(m)
t2 := getValueType(n)
return logicalFuncs[t1][t2](t, "or", m, n)
}
func numericExpr(m, n interface{}, cb func(float64, float64) float64) float64 {
typ := reflect.TypeOf(float64(0))
a := reflect.ValueOf(m).Convert(typ)
b := reflect.ValueOf(n).Convert(typ)
return cb(a.Float(), b.Float())
}
// plusFunc is an `+` operator.
var plusFunc = func(m, n interface{}) interface{} {
return numericExpr(m, n, func(a, b float64) float64 {
return a + b
})
}
// minusFunc is an `-` operator.
var minusFunc = func(m, n interface{}) interface{} {
return numericExpr(m, n, func(a, b float64) float64 {
return a - b
})
}
// mulFunc is an `*` operator.
var mulFunc = func(m, n interface{}) interface{} {
return numericExpr(m, n, func(a, b float64) float64 {
return a * b
})
}
// divFunc is an `DIV` operator.
var divFunc = func(m, n interface{}) interface{} {
return numericExpr(m, n, func(a, b float64) float64 {
return a / b
})
}
// modFunc is an 'MOD' operator.
var modFunc = func(m, n interface{}) interface{} {
return numericExpr(m, n, func(a, b float64) float64 {
return float64(int(a) % int(b))
})
}
|