| 1 |
package parser |
| 2 |
|
| 3 |
import ( |
| 4 |
"bufio" |
| 5 |
"container/list" |
| 6 |
"fmt" |
| 7 |
"io" |
| 8 |
"regexp" |
| 9 |
) |
| 10 |
|
| 11 |
const ( |
| 12 |
tokEOF = -(iota + 1) |
| 13 |
tokDoctype |
| 14 |
tokComment |
| 15 |
tokIndent |
| 16 |
tokOutdent |
| 17 |
tokBlank |
| 18 |
tokId |
| 19 |
tokClassName |
| 20 |
tokTag |
| 21 |
tokText |
| 22 |
tokAttribute |
| 23 |
tokIf |
| 24 |
tokElse |
| 25 |
tokEach |
| 26 |
tokAssignment |
| 27 |
tokImport |
| 28 |
tokNamedBlock |
| 29 |
tokExtends |
| 30 |
tokMixin |
| 31 |
tokMixinCall |
| 32 |
) |
| 33 |
|
| 34 |
const ( |
| 35 |
scnNewLine = iota |
| 36 |
scnLine |
| 37 |
scnEOF |
| 38 |
) |
| 39 |
|
| 40 |
type scanner struct { |
| 41 |
reader *bufio.Reader |
| 42 |
indentStack *list.List |
| 43 |
stash *list.List |
| 44 |
|
| 45 |
state int32 |
| 46 |
buffer string |
| 47 |
|
| 48 |
line int |
| 49 |
col int |
| 50 |
lastTokenLine int |
| 51 |
lastTokenCol int |
| 52 |
lastTokenSize int |
| 53 |
|
| 54 |
readRaw bool |
| 55 |
} |
| 56 |
|
| 57 |
type token struct { |
| 58 |
Kind rune |
| 59 |
Value string |
| 60 |
Data map[string]string |
| 61 |
} |
| 62 |
|
| 63 |
func newScanner(r io.Reader) *scanner { |
| 64 |
s := new(scanner) |
| 65 |
s.reader = bufio.NewReader(r) |
| 66 |
s.indentStack = list.New() |
| 67 |
s.stash = list.New() |
| 68 |
s.state = scnNewLine |
| 69 |
s.line = -1 |
| 70 |
s.col = 0 |
| 71 |
|
| 72 |
return s |
| 73 |
} |
| 74 |
|
| 75 |
func (s *scanner) Pos() SourcePosition { |
| 76 |
return SourcePosition{s.lastTokenLine + 1, s.lastTokenCol + 1, s.lastTokenSize, ""} |
| 77 |
} |
| 78 |
|
| 79 |
// Returns next token found in buffer |
| 80 |
func (s *scanner) Next() *token { |
| 81 |
if s.readRaw { |
| 82 |
s.readRaw = false |
| 83 |
return s.NextRaw() |
| 84 |
} |
| 85 |
|
| 86 |
s.ensureBuffer() |
| 87 |
|
| 88 |
if stashed := s.stash.Front(); stashed != nil { |
| 89 |
tok := stashed.Value.(*token) |
| 90 |
s.stash.Remove(stashed) |
| 91 |
return tok |
| 92 |
} |
| 93 |
|
| 94 |
switch s.state { |
| 95 |
case scnEOF: |
| 96 |
if outdent := s.indentStack.Back(); outdent != nil { |
| 97 |
s.indentStack.Remove(outdent) |
| 98 |
return &token{tokOutdent, "", nil} |
| 99 |
} |
| 100 |
|
| 101 |
return &token{tokEOF, "", nil} |
| 102 |
case scnNewLine: |
| 103 |
s.state = scnLine |
| 104 |
|
| 105 |
if tok := s.scanIndent(); tok != nil { |
| 106 |
return tok |
| 107 |
} |
| 108 |
|
| 109 |
return s.Next() |
| 110 |
case scnLine: |
| 111 |
if tok := s.scanMixin(); tok != nil { |
| 112 |
return tok |
| 113 |
} |
| 114 |
|
| 115 |
if tok := s.scanMixinCall(); tok != nil { |
| 116 |
return tok |
| 117 |
} |
| 118 |
|
| 119 |
if tok := s.scanDoctype(); tok != nil { |
| 120 |
return tok |
| 121 |
} |
| 122 |
|
| 123 |
if tok := s.scanCondition(); tok != nil { |
| 124 |
return tok |
| 125 |
} |
| 126 |
|
| 127 |
if tok := s.scanEach(); tok != nil { |
| 128 |
return tok |
| 129 |
} |
| 130 |
|
| 131 |
if tok := s.scanImport(); tok != nil { |
| 132 |
return tok |
| 133 |
} |
| 134 |
|
| 135 |
if tok := s.scanExtends(); tok != nil { |
| 136 |
return tok |
| 137 |
} |
| 138 |
|
| 139 |
if tok := s.scanBlock(); tok != nil { |
| 140 |
return tok |
| 141 |
} |
| 142 |
|
| 143 |
if tok := s.scanAssignment(); tok != nil { |
| 144 |
return tok |
| 145 |
} |
| 146 |
|
| 147 |
if tok := s.scanTag(); tok != nil { |
| 148 |
return tok |
| 149 |
} |
| 150 |
|
| 151 |
if tok := s.scanId(); tok != nil { |
| 152 |
return tok |
| 153 |
} |
| 154 |
|
| 155 |
if tok := s.scanClassName(); tok != nil { |
| 156 |
return tok |
| 157 |
} |
| 158 |
|
| 159 |
if tok := s.scanAttribute(); tok != nil { |
| 160 |
return tok |
| 161 |
} |
| 162 |
|
| 163 |
if tok := s.scanComment(); tok != nil { |
| 164 |
return tok |
| 165 |
} |
| 166 |
|
| 167 |
if tok := s.scanText(); tok != nil { |
| 168 |
return tok |
| 169 |
} |
| 170 |
} |
| 171 |
|
| 172 |
return nil |
| 173 |
} |
| 174 |
|
| 175 |
func (s *scanner) NextRaw() *token { |
| 176 |
result := "" |
| 177 |
level := 0 |
| 178 |
|
| 179 |
for { |
| 180 |
s.ensureBuffer() |
| 181 |
|
| 182 |
switch s.state { |
| 183 |
case scnEOF: |
| 184 |
return &token{tokText, result, map[string]string{"Mode": "raw"}} |
| 185 |
case scnNewLine: |
| 186 |
s.state = scnLine |
| 187 |
|
| 188 |
if tok := s.scanIndent(); tok != nil { |
| 189 |
if tok.Kind == tokIndent { |
| 190 |
level++ |
| 191 |
} else if tok.Kind == tokOutdent { |
| 192 |
level-- |
| 193 |
} else { |
| 194 |
result = result + "\n" |
| 195 |
continue |
| 196 |
} |
| 197 |
|
| 198 |
if level < 0 { |
| 199 |
s.stash.PushBack(&token{tokOutdent, "", nil}) |
| 200 |
|
| 201 |
if len(result) > 0 && result[len(result)-1] == '\n' { |
| 202 |
result = result[:len(result)-1] |
| 203 |
} |
| 204 |
|
| 205 |
return &token{tokText, result, map[string]string{"Mode": "raw"}} |
| 206 |
} |
| 207 |
} |
| 208 |
case scnLine: |
| 209 |
if len(result) > 0 { |
| 210 |
result = result + "\n" |
| 211 |
} |
| 212 |
for i := 0; i < level; i++ { |
| 213 |
result += "\t" |
| 214 |
} |
| 215 |
result = result + s.buffer |
| 216 |
s.consume(len(s.buffer)) |
| 217 |
} |
| 218 |
} |
| 219 |
|
| 220 |
return nil |
| 221 |
} |
| 222 |
|
| 223 |
var rgxIndent = regexp.MustCompile(`^(\s+)`) |
| 224 |
|
| 225 |
func (s *scanner) scanIndent() *token { |
| 226 |
if len(s.buffer) == 0 { |
| 227 |
return &token{tokBlank, "", nil} |
| 228 |
} |
| 229 |
|
| 230 |
var head *list.Element |
| 231 |
for head = s.indentStack.Front(); head != nil; head = head.Next() { |
| 232 |
value := head.Value.(*regexp.Regexp) |
| 233 |
|
| 234 |
if match := value.FindString(s.buffer); len(match) != 0 { |
| 235 |
s.consume(len(match)) |
| 236 |
} else { |
| 237 |
break |
| 238 |
} |
| 239 |
} |
| 240 |
|
| 241 |
newIndent := rgxIndent.FindString(s.buffer) |
| 242 |
|
| 243 |
if len(newIndent) != 0 && head == nil { |
| 244 |
s.indentStack.PushBack(regexp.MustCompile(regexp.QuoteMeta(newIndent))) |
| 245 |
s.consume(len(newIndent)) |
| 246 |
return &token{tokIndent, newIndent, nil} |
| 247 |
} |
| 248 |
|
| 249 |
if len(newIndent) == 0 && head != nil { |
| 250 |
for head != nil { |
| 251 |
next := head.Next() |
| 252 |
s.indentStack.Remove(head) |
| 253 |
if next == nil { |
| 254 |
return &token{tokOutdent, "", nil} |
| 255 |
} else { |
| 256 |
s.stash.PushBack(&token{tokOutdent, "", nil}) |
| 257 |
} |
| 258 |
head = next |
| 259 |
} |
| 260 |
} |
| 261 |
|
| 262 |
if len(newIndent) != 0 && head != nil { |
| 263 |
panic("Mismatching indentation. Please use a coherent indent schema.") |
| 264 |
} |
| 265 |
|
| 266 |
return nil |
| 267 |
} |
| 268 |
|
| 269 |
var rgxDoctype = regexp.MustCompile(`^(!!!|doctype)\s*(.*)`) |
| 270 |
|
| 271 |
func (s *scanner) scanDoctype() *token { |
| 272 |
if sm := rgxDoctype.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 273 |
if len(sm[2]) == 0 { |
| 274 |
sm[2] = "html" |
| 275 |
} |
| 276 |
|
| 277 |
s.consume(len(sm[0])) |
| 278 |
return &token{tokDoctype, sm[2], nil} |
| 279 |
} |
| 280 |
|
| 281 |
return nil |
| 282 |
} |
| 283 |
|
| 284 |
var rgxIf = regexp.MustCompile(`^if\s+(.+)$`) |
| 285 |
var rgxElse = regexp.MustCompile(`^else\s*`) |
| 286 |
|
| 287 |
func (s *scanner) scanCondition() *token { |
| 288 |
if sm := rgxIf.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 289 |
s.consume(len(sm[0])) |
| 290 |
return &token{tokIf, sm[1], nil} |
| 291 |
} |
| 292 |
|
| 293 |
if sm := rgxElse.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 294 |
s.consume(len(sm[0])) |
| 295 |
return &token{tokElse, "", nil} |
| 296 |
} |
| 297 |
|
| 298 |
return nil |
| 299 |
} |
| 300 |
|
| 301 |
var rgxEach = regexp.MustCompile(`^each\s+(\$[\w0-9\-_]*)(?:\s*,\s*(\$[\w0-9\-_]*))?\s+in\s+(.+)$`) |
| 302 |
|
| 303 |
func (s *scanner) scanEach() *token { |
| 304 |
if sm := rgxEach.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 305 |
s.consume(len(sm[0])) |
| 306 |
return &token{tokEach, sm[3], map[string]string{"X": sm[1], "Y": sm[2]}} |
| 307 |
} |
| 308 |
|
| 309 |
return nil |
| 310 |
} |
| 311 |
|
| 312 |
var rgxAssignment = regexp.MustCompile(`^(\$[\w0-9\-_]*)?\s*=\s*(.+)$`) |
| 313 |
|
| 314 |
func (s *scanner) scanAssignment() *token { |
| 315 |
if sm := rgxAssignment.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 316 |
s.consume(len(sm[0])) |
| 317 |
return &token{tokAssignment, sm[2], map[string]string{"X": sm[1]}} |
| 318 |
} |
| 319 |
|
| 320 |
return nil |
| 321 |
} |
| 322 |
|
| 323 |
var rgxComment = regexp.MustCompile(`^\/\/(-)?\s*(.*)$`) |
| 324 |
|
| 325 |
func (s *scanner) scanComment() *token { |
| 326 |
if sm := rgxComment.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 327 |
mode := "embed" |
| 328 |
if len(sm[1]) != 0 { |
| 329 |
mode = "silent" |
| 330 |
} |
| 331 |
|
| 332 |
s.consume(len(sm[0])) |
| 333 |
return &token{tokComment, sm[2], map[string]string{"Mode": mode}} |
| 334 |
} |
| 335 |
|
| 336 |
return nil |
| 337 |
} |
| 338 |
|
| 339 |
var rgxId = regexp.MustCompile(`^#([\w-]+)(?:\s*\?\s*(.*)$)?`) |
| 340 |
|
| 341 |
func (s *scanner) scanId() *token { |
| 342 |
if sm := rgxId.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 343 |
s.consume(len(sm[0])) |
| 344 |
return &token{tokId, sm[1], map[string]string{"Condition": sm[2]}} |
| 345 |
} |
| 346 |
|
| 347 |
return nil |
| 348 |
} |
| 349 |
|
| 350 |
var rgxClassName = regexp.MustCompile(`^\.([\w-]+)(?:\s*\?\s*(.*)$)?`) |
| 351 |
|
| 352 |
func (s *scanner) scanClassName() *token { |
| 353 |
if sm := rgxClassName.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 354 |
s.consume(len(sm[0])) |
| 355 |
return &token{tokClassName, sm[1], map[string]string{"Condition": sm[2]}} |
| 356 |
} |
| 357 |
|
| 358 |
return nil |
| 359 |
} |
| 360 |
|
| 361 |
var rgxAttribute = regexp.MustCompile(`^\[([\w\-:@\.]+)\s*(?:=\s*(\"([^\"\\]*)\"|([^\]]+)))?\](?:\s*\?\s*(.*)$)?`) |
| 362 |
|
| 363 |
func (s *scanner) scanAttribute() *token { |
| 364 |
if sm := rgxAttribute.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 365 |
s.consume(len(sm[0])) |
| 366 |
|
| 367 |
if len(sm[3]) != 0 || sm[2] == "" { |
| 368 |
return &token{tokAttribute, sm[1], map[string]string{"Content": sm[3], "Mode": "raw", "Condition": sm[5]}} |
| 369 |
} |
| 370 |
|
| 371 |
return &token{tokAttribute, sm[1], map[string]string{"Content": sm[4], "Mode": "expression", "Condition": sm[5]}} |
| 372 |
} |
| 373 |
|
| 374 |
return nil |
| 375 |
} |
| 376 |
|
| 377 |
var rgxImport = regexp.MustCompile(`^import\s+([0-9a-zA-Z_\-\. \/]*)$`) |
| 378 |
|
| 379 |
func (s *scanner) scanImport() *token { |
| 380 |
if sm := rgxImport.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 381 |
s.consume(len(sm[0])) |
| 382 |
return &token{tokImport, sm[1], nil} |
| 383 |
} |
| 384 |
|
| 385 |
return nil |
| 386 |
} |
| 387 |
|
| 388 |
var rgxExtends = regexp.MustCompile(`^extends\s+([0-9a-zA-Z_\-\. \/]*)$`) |
| 389 |
|
| 390 |
func (s *scanner) scanExtends() *token { |
| 391 |
if sm := rgxExtends.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 392 |
s.consume(len(sm[0])) |
| 393 |
return &token{tokExtends, sm[1], nil} |
| 394 |
} |
| 395 |
|
| 396 |
return nil |
| 397 |
} |
| 398 |
|
| 399 |
var rgxBlock = regexp.MustCompile(`^block\s+(?:(append|prepend)\s+)?([0-9a-zA-Z_\-\. \/]*)$`) |
| 400 |
|
| 401 |
func (s *scanner) scanBlock() *token { |
| 402 |
if sm := rgxBlock.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 403 |
s.consume(len(sm[0])) |
| 404 |
return &token{tokNamedBlock, sm[2], map[string]string{"Modifier": sm[1]}} |
| 405 |
} |
| 406 |
|
| 407 |
return nil |
| 408 |
} |
| 409 |
|
| 410 |
var rgxTag = regexp.MustCompile(`^(\w[-:\w]*)`) |
| 411 |
|
| 412 |
func (s *scanner) scanTag() *token { |
| 413 |
if sm := rgxTag.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 414 |
s.consume(len(sm[0])) |
| 415 |
return &token{tokTag, sm[1], nil} |
| 416 |
} |
| 417 |
|
| 418 |
return nil |
| 419 |
} |
| 420 |
|
| 421 |
var rgxMixin = regexp.MustCompile(`^mixin ([a-zA-Z_-]+\w*)(\(((\$\w*(,\s)?)*)\))?$`) |
| 422 |
|
| 423 |
func (s *scanner) scanMixin() *token { |
| 424 |
if sm := rgxMixin.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 425 |
s.consume(len(sm[0])) |
| 426 |
return &token{tokMixin, sm[1], map[string]string{"Args": sm[3]}} |
| 427 |
} |
| 428 |
|
| 429 |
return nil |
| 430 |
} |
| 431 |
|
| 432 |
var rgxMixinCall = regexp.MustCompile(`^\+([A-Za-z_-]+\w*)(\((.+(,\s)?)*\))?$`) |
| 433 |
|
| 434 |
func (s *scanner) scanMixinCall() *token { |
| 435 |
if sm := rgxMixinCall.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 436 |
s.consume(len(sm[0])) |
| 437 |
return &token{tokMixinCall, sm[1], map[string]string{"Args": sm[3]}} |
| 438 |
} |
| 439 |
|
| 440 |
return nil |
| 441 |
} |
| 442 |
|
| 443 |
var rgxText = regexp.MustCompile(`^(\|)? ?(.*)$`) |
| 444 |
|
| 445 |
func (s *scanner) scanText() *token { |
| 446 |
if sm := rgxText.FindStringSubmatch(s.buffer); len(sm) != 0 { |
| 447 |
s.consume(len(sm[0])) |
| 448 |
|
| 449 |
mode := "inline" |
| 450 |
if sm[1] == "|" { |
| 451 |
mode = "piped" |
| 452 |
} |
| 453 |
|
| 454 |
return &token{tokText, sm[2], map[string]string{"Mode": mode}} |
| 455 |
} |
| 456 |
|
| 457 |
return nil |
| 458 |
} |
| 459 |
|
| 460 |
// Moves position forward, and removes beginning of s.buffer (len bytes) |
| 461 |
func (s *scanner) consume(runes int) { |
| 462 |
if len(s.buffer) < runes { |
| 463 |
panic(fmt.Sprintf("Unable to consume %d runes from buffer.", runes)) |
| 464 |
} |
| 465 |
|
| 466 |
s.lastTokenLine = s.line |
| 467 |
s.lastTokenCol = s.col |
| 468 |
s.lastTokenSize = runes |
| 469 |
|
| 470 |
s.buffer = s.buffer[runes:] |
| 471 |
s.col += runes |
| 472 |
} |
| 473 |
|
| 474 |
// Reads string into s.buffer |
| 475 |
func (s *scanner) ensureBuffer() { |
| 476 |
if len(s.buffer) > 0 { |
| 477 |
return |
| 478 |
} |
| 479 |
|
| 480 |
buf, err := s.reader.ReadString('\n') |
| 481 |
|
| 482 |
if err != nil && err != io.EOF { |
| 483 |
panic(err) |
| 484 |
} else if err != nil && len(buf) == 0 { |
| 485 |
s.state = scnEOF |
| 486 |
} else { |
| 487 |
// endline "LF only" or "\n" use Unix, Linux, modern MacOS X, FreeBSD, BeOS, RISC OS |
| 488 |
if buf[len(buf)-1] == '\n' { |
| 489 |
buf = buf[:len(buf)-1] |
| 490 |
} |
| 491 |
// endline "CR+LF" or "\r\n" use internet protocols, DEC RT-11, Windows, CP/M, MS-DOS, OS/2, Symbian OS |
| 492 |
if len(buf) > 0 && buf[len(buf)-1] == '\r' { |
| 493 |
buf = buf[:len(buf)-1] |
| 494 |
} |
| 495 |
|
| 496 |
s.state = scnNewLine |
| 497 |
s.buffer = buf |
| 498 |
s.line += 1 |
| 499 |
s.col = 0 |
| 500 |
} |
| 501 |
} |
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