Mercurial > yakumo_izuru > aya
comparison vendor/github.com/dlclark/regexp2/match.go @ 66:787b5ee0289d draft
Use vendored modules
Signed-off-by: Izuru Yakumo <yakumo.izuru@chaotic.ninja>
author | yakumo.izuru |
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date | Sun, 23 Jul 2023 13:18:53 +0000 |
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65:6d985efa0f7a | 66:787b5ee0289d |
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1 package regexp2 | |
2 | |
3 import ( | |
4 "bytes" | |
5 "fmt" | |
6 ) | |
7 | |
8 // Match is a single regex result match that contains groups and repeated captures | |
9 // -Groups | |
10 // -Capture | |
11 type Match struct { | |
12 Group //embeded group 0 | |
13 | |
14 regex *Regexp | |
15 otherGroups []Group | |
16 | |
17 // input to the match | |
18 textpos int | |
19 textstart int | |
20 | |
21 capcount int | |
22 caps []int | |
23 sparseCaps map[int]int | |
24 | |
25 // output from the match | |
26 matches [][]int | |
27 matchcount []int | |
28 | |
29 // whether we've done any balancing with this match. If we | |
30 // have done balancing, we'll need to do extra work in Tidy(). | |
31 balancing bool | |
32 } | |
33 | |
34 // Group is an explicit or implit (group 0) matched group within the pattern | |
35 type Group struct { | |
36 Capture // the last capture of this group is embeded for ease of use | |
37 | |
38 Name string // group name | |
39 Captures []Capture // captures of this group | |
40 } | |
41 | |
42 // Capture is a single capture of text within the larger original string | |
43 type Capture struct { | |
44 // the original string | |
45 text []rune | |
46 // the position in the original string where the first character of | |
47 // captured substring was found. | |
48 Index int | |
49 // the length of the captured substring. | |
50 Length int | |
51 } | |
52 | |
53 // String returns the captured text as a String | |
54 func (c *Capture) String() string { | |
55 return string(c.text[c.Index : c.Index+c.Length]) | |
56 } | |
57 | |
58 // Runes returns the captured text as a rune slice | |
59 func (c *Capture) Runes() []rune { | |
60 return c.text[c.Index : c.Index+c.Length] | |
61 } | |
62 | |
63 func newMatch(regex *Regexp, capcount int, text []rune, startpos int) *Match { | |
64 m := Match{ | |
65 regex: regex, | |
66 matchcount: make([]int, capcount), | |
67 matches: make([][]int, capcount), | |
68 textstart: startpos, | |
69 balancing: false, | |
70 } | |
71 m.Name = "0" | |
72 m.text = text | |
73 m.matches[0] = make([]int, 2) | |
74 return &m | |
75 } | |
76 | |
77 func newMatchSparse(regex *Regexp, caps map[int]int, capcount int, text []rune, startpos int) *Match { | |
78 m := newMatch(regex, capcount, text, startpos) | |
79 m.sparseCaps = caps | |
80 return m | |
81 } | |
82 | |
83 func (m *Match) reset(text []rune, textstart int) { | |
84 m.text = text | |
85 m.textstart = textstart | |
86 for i := 0; i < len(m.matchcount); i++ { | |
87 m.matchcount[i] = 0 | |
88 } | |
89 m.balancing = false | |
90 } | |
91 | |
92 func (m *Match) tidy(textpos int) { | |
93 | |
94 interval := m.matches[0] | |
95 m.Index = interval[0] | |
96 m.Length = interval[1] | |
97 m.textpos = textpos | |
98 m.capcount = m.matchcount[0] | |
99 //copy our root capture to the list | |
100 m.Group.Captures = []Capture{m.Group.Capture} | |
101 | |
102 if m.balancing { | |
103 // The idea here is that we want to compact all of our unbalanced captures. To do that we | |
104 // use j basically as a count of how many unbalanced captures we have at any given time | |
105 // (really j is an index, but j/2 is the count). First we skip past all of the real captures | |
106 // until we find a balance captures. Then we check each subsequent entry. If it's a balance | |
107 // capture (it's negative), we decrement j. If it's a real capture, we increment j and copy | |
108 // it down to the last free position. | |
109 for cap := 0; cap < len(m.matchcount); cap++ { | |
110 limit := m.matchcount[cap] * 2 | |
111 matcharray := m.matches[cap] | |
112 | |
113 var i, j int | |
114 | |
115 for i = 0; i < limit; i++ { | |
116 if matcharray[i] < 0 { | |
117 break | |
118 } | |
119 } | |
120 | |
121 for j = i; i < limit; i++ { | |
122 if matcharray[i] < 0 { | |
123 // skip negative values | |
124 j-- | |
125 } else { | |
126 // but if we find something positive (an actual capture), copy it back to the last | |
127 // unbalanced position. | |
128 if i != j { | |
129 matcharray[j] = matcharray[i] | |
130 } | |
131 j++ | |
132 } | |
133 } | |
134 | |
135 m.matchcount[cap] = j / 2 | |
136 } | |
137 | |
138 m.balancing = false | |
139 } | |
140 } | |
141 | |
142 // isMatched tells if a group was matched by capnum | |
143 func (m *Match) isMatched(cap int) bool { | |
144 return cap < len(m.matchcount) && m.matchcount[cap] > 0 && m.matches[cap][m.matchcount[cap]*2-1] != (-3+1) | |
145 } | |
146 | |
147 // matchIndex returns the index of the last specified matched group by capnum | |
148 func (m *Match) matchIndex(cap int) int { | |
149 i := m.matches[cap][m.matchcount[cap]*2-2] | |
150 if i >= 0 { | |
151 return i | |
152 } | |
153 | |
154 return m.matches[cap][-3-i] | |
155 } | |
156 | |
157 // matchLength returns the length of the last specified matched group by capnum | |
158 func (m *Match) matchLength(cap int) int { | |
159 i := m.matches[cap][m.matchcount[cap]*2-1] | |
160 if i >= 0 { | |
161 return i | |
162 } | |
163 | |
164 return m.matches[cap][-3-i] | |
165 } | |
166 | |
167 // Nonpublic builder: add a capture to the group specified by "c" | |
168 func (m *Match) addMatch(c, start, l int) { | |
169 | |
170 if m.matches[c] == nil { | |
171 m.matches[c] = make([]int, 2) | |
172 } | |
173 | |
174 capcount := m.matchcount[c] | |
175 | |
176 if capcount*2+2 > len(m.matches[c]) { | |
177 oldmatches := m.matches[c] | |
178 newmatches := make([]int, capcount*8) | |
179 copy(newmatches, oldmatches[:capcount*2]) | |
180 m.matches[c] = newmatches | |
181 } | |
182 | |
183 m.matches[c][capcount*2] = start | |
184 m.matches[c][capcount*2+1] = l | |
185 m.matchcount[c] = capcount + 1 | |
186 //log.Printf("addMatch: c=%v, i=%v, l=%v ... matches: %v", c, start, l, m.matches) | |
187 } | |
188 | |
189 // Nonpublic builder: Add a capture to balance the specified group. This is used by the | |
190 // balanced match construct. (?<foo-foo2>...) | |
191 // | |
192 // If there were no such thing as backtracking, this would be as simple as calling RemoveMatch(c). | |
193 // However, since we have backtracking, we need to keep track of everything. | |
194 func (m *Match) balanceMatch(c int) { | |
195 m.balancing = true | |
196 | |
197 // we'll look at the last capture first | |
198 capcount := m.matchcount[c] | |
199 target := capcount*2 - 2 | |
200 | |
201 // first see if it is negative, and therefore is a reference to the next available | |
202 // capture group for balancing. If it is, we'll reset target to point to that capture. | |
203 if m.matches[c][target] < 0 { | |
204 target = -3 - m.matches[c][target] | |
205 } | |
206 | |
207 // move back to the previous capture | |
208 target -= 2 | |
209 | |
210 // if the previous capture is a reference, just copy that reference to the end. Otherwise, point to it. | |
211 if target >= 0 && m.matches[c][target] < 0 { | |
212 m.addMatch(c, m.matches[c][target], m.matches[c][target+1]) | |
213 } else { | |
214 m.addMatch(c, -3-target, -4-target /* == -3 - (target + 1) */) | |
215 } | |
216 } | |
217 | |
218 // Nonpublic builder: removes a group match by capnum | |
219 func (m *Match) removeMatch(c int) { | |
220 m.matchcount[c]-- | |
221 } | |
222 | |
223 // GroupCount returns the number of groups this match has matched | |
224 func (m *Match) GroupCount() int { | |
225 return len(m.matchcount) | |
226 } | |
227 | |
228 // GroupByName returns a group based on the name of the group, or nil if the group name does not exist | |
229 func (m *Match) GroupByName(name string) *Group { | |
230 num := m.regex.GroupNumberFromName(name) | |
231 if num < 0 { | |
232 return nil | |
233 } | |
234 return m.GroupByNumber(num) | |
235 } | |
236 | |
237 // GroupByNumber returns a group based on the number of the group, or nil if the group number does not exist | |
238 func (m *Match) GroupByNumber(num int) *Group { | |
239 // check our sparse map | |
240 if m.sparseCaps != nil { | |
241 if newNum, ok := m.sparseCaps[num]; ok { | |
242 num = newNum | |
243 } | |
244 } | |
245 if num >= len(m.matchcount) || num < 0 { | |
246 return nil | |
247 } | |
248 | |
249 if num == 0 { | |
250 return &m.Group | |
251 } | |
252 | |
253 m.populateOtherGroups() | |
254 | |
255 return &m.otherGroups[num-1] | |
256 } | |
257 | |
258 // Groups returns all the capture groups, starting with group 0 (the full match) | |
259 func (m *Match) Groups() []Group { | |
260 m.populateOtherGroups() | |
261 g := make([]Group, len(m.otherGroups)+1) | |
262 g[0] = m.Group | |
263 copy(g[1:], m.otherGroups) | |
264 return g | |
265 } | |
266 | |
267 func (m *Match) populateOtherGroups() { | |
268 // Construct all the Group objects first time called | |
269 if m.otherGroups == nil { | |
270 m.otherGroups = make([]Group, len(m.matchcount)-1) | |
271 for i := 0; i < len(m.otherGroups); i++ { | |
272 m.otherGroups[i] = newGroup(m.regex.GroupNameFromNumber(i+1), m.text, m.matches[i+1], m.matchcount[i+1]) | |
273 } | |
274 } | |
275 } | |
276 | |
277 func (m *Match) groupValueAppendToBuf(groupnum int, buf *bytes.Buffer) { | |
278 c := m.matchcount[groupnum] | |
279 if c == 0 { | |
280 return | |
281 } | |
282 | |
283 matches := m.matches[groupnum] | |
284 | |
285 index := matches[(c-1)*2] | |
286 last := index + matches[(c*2)-1] | |
287 | |
288 for ; index < last; index++ { | |
289 buf.WriteRune(m.text[index]) | |
290 } | |
291 } | |
292 | |
293 func newGroup(name string, text []rune, caps []int, capcount int) Group { | |
294 g := Group{} | |
295 g.text = text | |
296 if capcount > 0 { | |
297 g.Index = caps[(capcount-1)*2] | |
298 g.Length = caps[(capcount*2)-1] | |
299 } | |
300 g.Name = name | |
301 g.Captures = make([]Capture, capcount) | |
302 for i := 0; i < capcount; i++ { | |
303 g.Captures[i] = Capture{ | |
304 text: text, | |
305 Index: caps[i*2], | |
306 Length: caps[i*2+1], | |
307 } | |
308 } | |
309 //log.Printf("newGroup! capcount %v, %+v", capcount, g) | |
310 | |
311 return g | |
312 } | |
313 | |
314 func (m *Match) dump() string { | |
315 buf := &bytes.Buffer{} | |
316 buf.WriteRune('\n') | |
317 if len(m.sparseCaps) > 0 { | |
318 for k, v := range m.sparseCaps { | |
319 fmt.Fprintf(buf, "Slot %v -> %v\n", k, v) | |
320 } | |
321 } | |
322 | |
323 for i, g := range m.Groups() { | |
324 fmt.Fprintf(buf, "Group %v (%v), %v caps:\n", i, g.Name, len(g.Captures)) | |
325 | |
326 for _, c := range g.Captures { | |
327 fmt.Fprintf(buf, " (%v, %v) %v\n", c.Index, c.Length, c.String()) | |
328 } | |
329 } | |
330 /* | |
331 for i := 0; i < len(m.matchcount); i++ { | |
332 fmt.Fprintf(buf, "\nGroup %v (%v):\n", i, m.regex.GroupNameFromNumber(i)) | |
333 | |
334 for j := 0; j < m.matchcount[i]; j++ { | |
335 text := "" | |
336 | |
337 if m.matches[i][j*2] >= 0 { | |
338 start := m.matches[i][j*2] | |
339 text = m.text[start : start+m.matches[i][j*2+1]] | |
340 } | |
341 | |
342 fmt.Fprintf(buf, " (%v, %v) %v\n", m.matches[i][j*2], m.matches[i][j*2+1], text) | |
343 } | |
344 } | |
345 */ | |
346 return buf.String() | |
347 } |