-
Notifications
You must be signed in to change notification settings - Fork 1
/
splitter.go
290 lines (271 loc) · 7.31 KB
/
splitter.go
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
package splitter
import (
"fmt"
)
// Splitter is the actual splitter interface
type Splitter interface {
// Split performs a split on the supplied string - returns the split parts and any error encountered
//
// If an error is returned, it will always be of type splittingError
Split(s string, options ...Option) ([]string, error)
// AddDefaultOptions adds default options for the splitter (other options can also be added when using Split)
AddDefaultOptions(options ...Option) Splitter
}
// NewSplitter creates a new splitter
//
// the `separator` arg is the rune on which to split
//
// the optional `encs` varargs are the enclosures (e.g. brackets, quotes) to be taken into consideration when splitting
//
// An error is returned if any of enclosures specified match any other enclosure `Start`/`End`
func NewSplitter(separator rune, encs ...*Enclosure) (Splitter, error) {
result := &splitter{
separator: separator,
enclosures: make([]Enclosure, 0, len(encs)),
openers: map[rune]Enclosure{},
closers: map[rune]Enclosure{},
defOptions: make([]Option, 0),
seenOptions: map[Option]bool{},
}
for i, enc := range encs {
if enc != nil {
if _, exists := result.openers[enc.Start]; exists {
return nil, fmt.Errorf("existing start encloser ('%s' in Enclosure[%d])", string(enc.Start), i+1)
}
if _, exists := result.closers[enc.End]; exists {
return nil, fmt.Errorf("existing end encloser ('%s' in Enclosure[%d])", string(enc.End), i+1)
}
cEnc := enc.clone()
result.openers[enc.Start] = cEnc
result.closers[enc.End] = cEnc
result.enclosures = append(result.enclosures, *enc)
}
}
return result, nil
}
// MustCreateSplitter is the same as NewSplitter, except that it panics in case of error
func MustCreateSplitter(separator rune, encs ...*Enclosure) Splitter {
if s, err := NewSplitter(separator, encs...); err != nil {
panic(err)
} else {
return s
}
}
type splitter struct {
separator rune
enclosures []Enclosure
openers map[rune]Enclosure
closers map[rune]Enclosure
defOptions []Option
seenOptions map[Option]bool
}
func (s *splitter) Split(str string, options ...Option) ([]string, error) {
return newSplitterContext(str, s, s.mergeOptions(options)).split()
}
func (s *splitter) AddDefaultOptions(options ...Option) Splitter {
for _, opt := range options {
if opt != nil && !s.seenOptions[opt] {
s.defOptions = append(s.defOptions, opt)
s.seenOptions[opt] = true
}
}
return s
}
func (s *splitter) mergeOptions(addOpts []Option) []Option {
addLen := len(addOpts)
defLen := len(s.defOptions)
if addLen == 0 {
return s.defOptions
} else if defLen == 0 && addLen != 0 {
result := make([]Option, 0, addLen)
seen := map[Option]bool{}
for _, opt := range addOpts {
if opt != nil && !seen[opt] {
result = append(result, opt)
}
}
return result
}
result := make([]Option, 0, len(s.defOptions)+len(addOpts))
result = append(result, s.defOptions...)
seen := map[Option]bool{}
for _, opt := range addOpts {
if opt != nil && !seen[opt] && !s.seenOptions[opt] {
result = append(result, opt)
seen[opt] = true
}
}
return result
}
type splitterContext struct {
splitter *splitter
options []Option
runes []rune
pos int
rune rune
len int
lastAt int
current *subPart
stack []*subPart
delims []SubPart
captured []string
skipped int
}
func newSplitterContext(str string, splitter *splitter, options []Option) *splitterContext {
runes := []rune(str)
cp := 1
for _, r := range runes {
if r == splitter.separator {
cp++
}
}
return &splitterContext{
splitter: splitter,
options: options,
runes: runes,
lastAt: 0,
len: len(runes),
current: nil,
stack: make([]*subPart, 0),
delims: make([]SubPart, 0),
captured: make([]string, 0, cp),
}
}
func (ctx *splitterContext) split() ([]string, error) {
ctx.pos = 0
for ; ctx.pos < ctx.len; ctx.pos++ {
ctx.rune = ctx.runes[ctx.pos]
if ctx.rune == ctx.splitter.separator {
if !ctx.inAny() {
if err := ctx.purge(ctx.pos, false); err != nil {
return nil, err
}
}
} else if isEnd, inQuote := ctx.isQuoteEnd(); isEnd {
ctx.pop(ctx.pos)
} else {
if !inQuote {
if isClose, skipClose := ctx.isClose(); isClose && !skipClose {
ctx.pop(ctx.pos)
} else if enc, isOpen := ctx.isOpener(); isOpen {
ctx.push(enc, ctx.pos)
} else if cEnc, ok := ctx.splitter.closers[ctx.rune]; ok && !skipClose {
return nil, newSplittingError(Unopened, ctx.pos, ctx.rune, &cEnc)
}
}
}
}
if ctx.inAny() {
return nil, newSplittingError(Unclosed, ctx.current.openPos, ctx.current.enc.Start, &ctx.current.enc)
}
if err := ctx.purge(ctx.len, true); err != nil {
return nil, err
}
return ctx.captured, nil
}
func (ctx *splitterContext) isQuoteEnd() (isEnd bool, inQuote bool) {
if ctx.current != nil && ctx.current.enc.IsQuote {
inQuote = true
if ctx.current.enc.End == ctx.rune {
isEnd = true
if ctx.current.enc.isDoubleEscaping() {
if ctx.pos < ctx.len-1 && ctx.runes[ctx.pos+1] == ctx.rune {
isEnd = false
ctx.pos++
}
} else if ctx.current.enc.isEscapable() {
escaped := false
minPos := ctx.current.openPos
for i := ctx.pos - 1; i > minPos; i-- {
if ctx.runes[i] == ctx.current.enc.Escape {
escaped = !escaped
} else {
break
}
}
isEnd = !escaped
}
}
}
return
}
func (ctx *splitterContext) purge(i int, isLast bool) (err error) {
if i >= ctx.lastAt {
ctx.purgeFixed(i)
capture := string(ctx.runes[ctx.lastAt:i])
addIt := true
cLen := len(ctx.captured)
for _, o := range ctx.options {
capture, addIt, err = o.Apply(capture, ctx.lastAt, ctx.len, cLen, ctx.skipped, isLast, ctx.delims...)
if !addIt || err != nil {
break
}
}
err = asSplittingError(err, ctx.lastAt)
if addIt {
ctx.captured = append(ctx.captured, capture)
} else {
ctx.skipped++
}
ctx.lastAt = i + 1
ctx.delims = make([]SubPart, 0)
}
return
}
func (ctx *splitterContext) inAny() bool {
return ctx.current != nil
}
func (ctx *splitterContext) isClose() (is bool, skip bool) {
skip = false
is = ctx.current != nil && ctx.current.enc.End == ctx.rune
if ctx.pos > 0 {
if enc, ok := ctx.splitter.closers[ctx.rune]; ok {
skip = enc.isBracketEscapable() && ctx.runes[ctx.pos-1] == enc.Escape
}
}
return
}
func (ctx *splitterContext) isOpener() (Enclosure, bool) {
enc, is := ctx.splitter.openers[ctx.rune]
skip := is && ctx.pos > 0 && enc.isBracketEscapable() && ctx.runes[ctx.pos-1] == enc.Escape
is = is && !skip
return enc, is
}
func (ctx *splitterContext) push(enc Enclosure, pos int) {
if ctx.current != nil {
ctx.stack = append(ctx.stack, ctx.current)
}
ctx.current = &subPart{
openPos: pos,
enc: enc,
ctx: ctx,
}
if len(ctx.stack) == 0 {
ctx.purgeFixed(pos)
ctx.delims = append(ctx.delims, ctx.current)
}
}
func (ctx *splitterContext) purgeFixed(pos int) {
last := ctx.lastAt
if len(ctx.delims) > 0 {
last = ctx.delims[len(ctx.delims)-1].EndPos() + 1
}
if last < pos {
ctx.delims = append(ctx.delims, &subPart{
enc: Enclosure{},
openPos: last,
closePos: pos - 1,
ctx: ctx,
fixed: true,
})
}
}
func (ctx *splitterContext) pop(pos int) {
ctx.current.closePos = pos
if l := len(ctx.stack); l > 0 {
ctx.current = ctx.stack[l-1]
ctx.stack = ctx.stack[0 : l-1]
} else {
ctx.current = nil
}
}