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| 1 # -*- coding: utf-8 -*- |
| 2 """ |
| 3 jinja2.parser |
| 4 ~~~~~~~~~~~~~ |
| 5 |
| 6 Implements the template parser. |
| 7 |
| 8 :copyright: (c) 2010 by the Jinja Team. |
| 9 :license: BSD, see LICENSE for more details. |
| 10 """ |
| 11 from jinja2 import nodes |
| 12 from jinja2.exceptions import TemplateSyntaxError, TemplateAssertionError |
| 13 from jinja2.utils import next |
| 14 from jinja2.lexer import describe_token, describe_token_expr |
| 15 |
| 16 |
| 17 #: statements that callinto |
| 18 _statement_keywords = frozenset(['for', 'if', 'block', 'extends', 'print', |
| 19 'macro', 'include', 'from', 'import', |
| 20 'set']) |
| 21 _compare_operators = frozenset(['eq', 'ne', 'lt', 'lteq', 'gt', 'gteq']) |
| 22 |
| 23 |
| 24 class Parser(object): |
| 25 """This is the central parsing class Jinja2 uses. It's passed to |
| 26 extensions and can be used to parse expressions or statements. |
| 27 """ |
| 28 |
| 29 def __init__(self, environment, source, name=None, filename=None, |
| 30 state=None): |
| 31 self.environment = environment |
| 32 self.stream = environment._tokenize(source, name, filename, state) |
| 33 self.name = name |
| 34 self.filename = filename |
| 35 self.closed = False |
| 36 self.extensions = {} |
| 37 for extension in environment.iter_extensions(): |
| 38 for tag in extension.tags: |
| 39 self.extensions[tag] = extension.parse |
| 40 self._last_identifier = 0 |
| 41 self._tag_stack = [] |
| 42 self._end_token_stack = [] |
| 43 |
| 44 def fail(self, msg, lineno=None, exc=TemplateSyntaxError): |
| 45 """Convenience method that raises `exc` with the message, passed |
| 46 line number or last line number as well as the current name and |
| 47 filename. |
| 48 """ |
| 49 if lineno is None: |
| 50 lineno = self.stream.current.lineno |
| 51 raise exc(msg, lineno, self.name, self.filename) |
| 52 |
| 53 def _fail_ut_eof(self, name, end_token_stack, lineno): |
| 54 expected = [] |
| 55 for exprs in end_token_stack: |
| 56 expected.extend(map(describe_token_expr, exprs)) |
| 57 if end_token_stack: |
| 58 currently_looking = ' or '.join( |
| 59 "'%s'" % describe_token_expr(expr) |
| 60 for expr in end_token_stack[-1]) |
| 61 else: |
| 62 currently_looking = None |
| 63 |
| 64 if name is None: |
| 65 message = ['Unexpected end of template.'] |
| 66 else: |
| 67 message = ['Encountered unknown tag \'%s\'.' % name] |
| 68 |
| 69 if currently_looking: |
| 70 if name is not None and name in expected: |
| 71 message.append('You probably made a nesting mistake. Jinja ' |
| 72 'is expecting this tag, but currently looking ' |
| 73 'for %s.' % currently_looking) |
| 74 else: |
| 75 message.append('Jinja was looking for the following tags: ' |
| 76 '%s.' % currently_looking) |
| 77 |
| 78 if self._tag_stack: |
| 79 message.append('The innermost block that needs to be ' |
| 80 'closed is \'%s\'.' % self._tag_stack[-1]) |
| 81 |
| 82 self.fail(' '.join(message), lineno) |
| 83 |
| 84 def fail_unknown_tag(self, name, lineno=None): |
| 85 """Called if the parser encounters an unknown tag. Tries to fail |
| 86 with a human readable error message that could help to identify |
| 87 the problem. |
| 88 """ |
| 89 return self._fail_ut_eof(name, self._end_token_stack, lineno) |
| 90 |
| 91 def fail_eof(self, end_tokens=None, lineno=None): |
| 92 """Like fail_unknown_tag but for end of template situations.""" |
| 93 stack = list(self._end_token_stack) |
| 94 if end_tokens is not None: |
| 95 stack.append(end_tokens) |
| 96 return self._fail_ut_eof(None, stack, lineno) |
| 97 |
| 98 def is_tuple_end(self, extra_end_rules=None): |
| 99 """Are we at the end of a tuple?""" |
| 100 if self.stream.current.type in ('variable_end', 'block_end', 'rparen'): |
| 101 return True |
| 102 elif extra_end_rules is not None: |
| 103 return self.stream.current.test_any(extra_end_rules) |
| 104 return False |
| 105 |
| 106 def free_identifier(self, lineno=None): |
| 107 """Return a new free identifier as :class:`~jinja2.nodes.InternalName`."
"" |
| 108 self._last_identifier += 1 |
| 109 rv = object.__new__(nodes.InternalName) |
| 110 nodes.Node.__init__(rv, 'fi%d' % self._last_identifier, lineno=lineno) |
| 111 return rv |
| 112 |
| 113 def parse_statement(self): |
| 114 """Parse a single statement.""" |
| 115 token = self.stream.current |
| 116 if token.type != 'name': |
| 117 self.fail('tag name expected', token.lineno) |
| 118 self._tag_stack.append(token.value) |
| 119 pop_tag = True |
| 120 try: |
| 121 if token.value in _statement_keywords: |
| 122 return getattr(self, 'parse_' + self.stream.current.value)() |
| 123 if token.value == 'call': |
| 124 return self.parse_call_block() |
| 125 if token.value == 'filter': |
| 126 return self.parse_filter_block() |
| 127 ext = self.extensions.get(token.value) |
| 128 if ext is not None: |
| 129 return ext(self) |
| 130 |
| 131 # did not work out, remove the token we pushed by accident |
| 132 # from the stack so that the unknown tag fail function can |
| 133 # produce a proper error message. |
| 134 self._tag_stack.pop() |
| 135 pop_tag = False |
| 136 self.fail_unknown_tag(token.value, token.lineno) |
| 137 finally: |
| 138 if pop_tag: |
| 139 self._tag_stack.pop() |
| 140 |
| 141 def parse_statements(self, end_tokens, drop_needle=False): |
| 142 """Parse multiple statements into a list until one of the end tokens |
| 143 is reached. This is used to parse the body of statements as it also |
| 144 parses template data if appropriate. The parser checks first if the |
| 145 current token is a colon and skips it if there is one. Then it checks |
| 146 for the block end and parses until if one of the `end_tokens` is |
| 147 reached. Per default the active token in the stream at the end of |
| 148 the call is the matched end token. If this is not wanted `drop_needle` |
| 149 can be set to `True` and the end token is removed. |
| 150 """ |
| 151 # the first token may be a colon for python compatibility |
| 152 self.stream.skip_if('colon') |
| 153 |
| 154 # in the future it would be possible to add whole code sections |
| 155 # by adding some sort of end of statement token and parsing those here. |
| 156 self.stream.expect('block_end') |
| 157 result = self.subparse(end_tokens) |
| 158 |
| 159 # we reached the end of the template too early, the subparser |
| 160 # does not check for this, so we do that now |
| 161 if self.stream.current.type == 'eof': |
| 162 self.fail_eof(end_tokens) |
| 163 |
| 164 if drop_needle: |
| 165 next(self.stream) |
| 166 return result |
| 167 |
| 168 def parse_set(self): |
| 169 """Parse an assign statement.""" |
| 170 lineno = next(self.stream).lineno |
| 171 target = self.parse_assign_target() |
| 172 self.stream.expect('assign') |
| 173 expr = self.parse_tuple() |
| 174 return nodes.Assign(target, expr, lineno=lineno) |
| 175 |
| 176 def parse_for(self): |
| 177 """Parse a for loop.""" |
| 178 lineno = self.stream.expect('name:for').lineno |
| 179 target = self.parse_assign_target(extra_end_rules=('name:in',)) |
| 180 self.stream.expect('name:in') |
| 181 iter = self.parse_tuple(with_condexpr=False, |
| 182 extra_end_rules=('name:recursive',)) |
| 183 test = None |
| 184 if self.stream.skip_if('name:if'): |
| 185 test = self.parse_expression() |
| 186 recursive = self.stream.skip_if('name:recursive') |
| 187 body = self.parse_statements(('name:endfor', 'name:else')) |
| 188 if next(self.stream).value == 'endfor': |
| 189 else_ = [] |
| 190 else: |
| 191 else_ = self.parse_statements(('name:endfor',), drop_needle=True) |
| 192 return nodes.For(target, iter, body, else_, test, |
| 193 recursive, lineno=lineno) |
| 194 |
| 195 def parse_if(self): |
| 196 """Parse an if construct.""" |
| 197 node = result = nodes.If(lineno=self.stream.expect('name:if').lineno) |
| 198 while 1: |
| 199 node.test = self.parse_tuple(with_condexpr=False) |
| 200 node.body = self.parse_statements(('name:elif', 'name:else', |
| 201 'name:endif')) |
| 202 token = next(self.stream) |
| 203 if token.test('name:elif'): |
| 204 new_node = nodes.If(lineno=self.stream.current.lineno) |
| 205 node.else_ = [new_node] |
| 206 node = new_node |
| 207 continue |
| 208 elif token.test('name:else'): |
| 209 node.else_ = self.parse_statements(('name:endif',), |
| 210 drop_needle=True) |
| 211 else: |
| 212 node.else_ = [] |
| 213 break |
| 214 return result |
| 215 |
| 216 def parse_block(self): |
| 217 node = nodes.Block(lineno=next(self.stream).lineno) |
| 218 node.name = self.stream.expect('name').value |
| 219 node.scoped = self.stream.skip_if('name:scoped') |
| 220 |
| 221 # common problem people encounter when switching from django |
| 222 # to jinja. we do not support hyphens in block names, so let's |
| 223 # raise a nicer error message in that case. |
| 224 if self.stream.current.type == 'sub': |
| 225 self.fail('Block names in Jinja have to be valid Python ' |
| 226 'identifiers and may not contain hypens, use an ' |
| 227 'underscore instead.') |
| 228 |
| 229 node.body = self.parse_statements(('name:endblock',), drop_needle=True) |
| 230 self.stream.skip_if('name:' + node.name) |
| 231 return node |
| 232 |
| 233 def parse_extends(self): |
| 234 node = nodes.Extends(lineno=next(self.stream).lineno) |
| 235 node.template = self.parse_expression() |
| 236 return node |
| 237 |
| 238 def parse_import_context(self, node, default): |
| 239 if self.stream.current.test_any('name:with', 'name:without') and \ |
| 240 self.stream.look().test('name:context'): |
| 241 node.with_context = next(self.stream).value == 'with' |
| 242 self.stream.skip() |
| 243 else: |
| 244 node.with_context = default |
| 245 return node |
| 246 |
| 247 def parse_include(self): |
| 248 node = nodes.Include(lineno=next(self.stream).lineno) |
| 249 node.template = self.parse_expression() |
| 250 if self.stream.current.test('name:ignore') and \ |
| 251 self.stream.look().test('name:missing'): |
| 252 node.ignore_missing = True |
| 253 self.stream.skip(2) |
| 254 else: |
| 255 node.ignore_missing = False |
| 256 return self.parse_import_context(node, True) |
| 257 |
| 258 def parse_import(self): |
| 259 node = nodes.Import(lineno=next(self.stream).lineno) |
| 260 node.template = self.parse_expression() |
| 261 self.stream.expect('name:as') |
| 262 node.target = self.parse_assign_target(name_only=True).name |
| 263 return self.parse_import_context(node, False) |
| 264 |
| 265 def parse_from(self): |
| 266 node = nodes.FromImport(lineno=next(self.stream).lineno) |
| 267 node.template = self.parse_expression() |
| 268 self.stream.expect('name:import') |
| 269 node.names = [] |
| 270 |
| 271 def parse_context(): |
| 272 if self.stream.current.value in ('with', 'without') and \ |
| 273 self.stream.look().test('name:context'): |
| 274 node.with_context = next(self.stream).value == 'with' |
| 275 self.stream.skip() |
| 276 return True |
| 277 return False |
| 278 |
| 279 while 1: |
| 280 if node.names: |
| 281 self.stream.expect('comma') |
| 282 if self.stream.current.type == 'name': |
| 283 if parse_context(): |
| 284 break |
| 285 target = self.parse_assign_target(name_only=True) |
| 286 if target.name.startswith('_'): |
| 287 self.fail('names starting with an underline can not ' |
| 288 'be imported', target.lineno, |
| 289 exc=TemplateAssertionError) |
| 290 if self.stream.skip_if('name:as'): |
| 291 alias = self.parse_assign_target(name_only=True) |
| 292 node.names.append((target.name, alias.name)) |
| 293 else: |
| 294 node.names.append(target.name) |
| 295 if parse_context() or self.stream.current.type != 'comma': |
| 296 break |
| 297 else: |
| 298 break |
| 299 if not hasattr(node, 'with_context'): |
| 300 node.with_context = False |
| 301 self.stream.skip_if('comma') |
| 302 return node |
| 303 |
| 304 def parse_signature(self, node): |
| 305 node.args = args = [] |
| 306 node.defaults = defaults = [] |
| 307 self.stream.expect('lparen') |
| 308 while self.stream.current.type != 'rparen': |
| 309 if args: |
| 310 self.stream.expect('comma') |
| 311 arg = self.parse_assign_target(name_only=True) |
| 312 arg.set_ctx('param') |
| 313 if self.stream.skip_if('assign'): |
| 314 defaults.append(self.parse_expression()) |
| 315 args.append(arg) |
| 316 self.stream.expect('rparen') |
| 317 |
| 318 def parse_call_block(self): |
| 319 node = nodes.CallBlock(lineno=next(self.stream).lineno) |
| 320 if self.stream.current.type == 'lparen': |
| 321 self.parse_signature(node) |
| 322 else: |
| 323 node.args = [] |
| 324 node.defaults = [] |
| 325 |
| 326 node.call = self.parse_expression() |
| 327 if not isinstance(node.call, nodes.Call): |
| 328 self.fail('expected call', node.lineno) |
| 329 node.body = self.parse_statements(('name:endcall',), drop_needle=True) |
| 330 return node |
| 331 |
| 332 def parse_filter_block(self): |
| 333 node = nodes.FilterBlock(lineno=next(self.stream).lineno) |
| 334 node.filter = self.parse_filter(None, start_inline=True) |
| 335 node.body = self.parse_statements(('name:endfilter',), |
| 336 drop_needle=True) |
| 337 return node |
| 338 |
| 339 def parse_macro(self): |
| 340 node = nodes.Macro(lineno=next(self.stream).lineno) |
| 341 node.name = self.parse_assign_target(name_only=True).name |
| 342 self.parse_signature(node) |
| 343 node.body = self.parse_statements(('name:endmacro',), |
| 344 drop_needle=True) |
| 345 return node |
| 346 |
| 347 def parse_print(self): |
| 348 node = nodes.Output(lineno=next(self.stream).lineno) |
| 349 node.nodes = [] |
| 350 while self.stream.current.type != 'block_end': |
| 351 if node.nodes: |
| 352 self.stream.expect('comma') |
| 353 node.nodes.append(self.parse_expression()) |
| 354 return node |
| 355 |
| 356 def parse_assign_target(self, with_tuple=True, name_only=False, |
| 357 extra_end_rules=None): |
| 358 """Parse an assignment target. As Jinja2 allows assignments to |
| 359 tuples, this function can parse all allowed assignment targets. Per |
| 360 default assignments to tuples are parsed, that can be disable however |
| 361 by setting `with_tuple` to `False`. If only assignments to names are |
| 362 wanted `name_only` can be set to `True`. The `extra_end_rules` |
| 363 parameter is forwarded to the tuple parsing function. |
| 364 """ |
| 365 if name_only: |
| 366 token = self.stream.expect('name') |
| 367 target = nodes.Name(token.value, 'store', lineno=token.lineno) |
| 368 else: |
| 369 if with_tuple: |
| 370 target = self.parse_tuple(simplified=True, |
| 371 extra_end_rules=extra_end_rules) |
| 372 else: |
| 373 target = self.parse_primary() |
| 374 target.set_ctx('store') |
| 375 if not target.can_assign(): |
| 376 self.fail('can\'t assign to %r' % target.__class__. |
| 377 __name__.lower(), target.lineno) |
| 378 return target |
| 379 |
| 380 def parse_expression(self, with_condexpr=True): |
| 381 """Parse an expression. Per default all expressions are parsed, if |
| 382 the optional `with_condexpr` parameter is set to `False` conditional |
| 383 expressions are not parsed. |
| 384 """ |
| 385 if with_condexpr: |
| 386 return self.parse_condexpr() |
| 387 return self.parse_or() |
| 388 |
| 389 def parse_condexpr(self): |
| 390 lineno = self.stream.current.lineno |
| 391 expr1 = self.parse_or() |
| 392 while self.stream.skip_if('name:if'): |
| 393 expr2 = self.parse_or() |
| 394 if self.stream.skip_if('name:else'): |
| 395 expr3 = self.parse_condexpr() |
| 396 else: |
| 397 expr3 = None |
| 398 expr1 = nodes.CondExpr(expr2, expr1, expr3, lineno=lineno) |
| 399 lineno = self.stream.current.lineno |
| 400 return expr1 |
| 401 |
| 402 def parse_or(self): |
| 403 lineno = self.stream.current.lineno |
| 404 left = self.parse_and() |
| 405 while self.stream.skip_if('name:or'): |
| 406 right = self.parse_and() |
| 407 left = nodes.Or(left, right, lineno=lineno) |
| 408 lineno = self.stream.current.lineno |
| 409 return left |
| 410 |
| 411 def parse_and(self): |
| 412 lineno = self.stream.current.lineno |
| 413 left = self.parse_not() |
| 414 while self.stream.skip_if('name:and'): |
| 415 right = self.parse_not() |
| 416 left = nodes.And(left, right, lineno=lineno) |
| 417 lineno = self.stream.current.lineno |
| 418 return left |
| 419 |
| 420 def parse_not(self): |
| 421 if self.stream.current.test('name:not'): |
| 422 lineno = next(self.stream).lineno |
| 423 return nodes.Not(self.parse_not(), lineno=lineno) |
| 424 return self.parse_compare() |
| 425 |
| 426 def parse_compare(self): |
| 427 lineno = self.stream.current.lineno |
| 428 expr = self.parse_add() |
| 429 ops = [] |
| 430 while 1: |
| 431 token_type = self.stream.current.type |
| 432 if token_type in _compare_operators: |
| 433 next(self.stream) |
| 434 ops.append(nodes.Operand(token_type, self.parse_add())) |
| 435 elif self.stream.skip_if('name:in'): |
| 436 ops.append(nodes.Operand('in', self.parse_add())) |
| 437 elif self.stream.current.test('name:not') and \ |
| 438 self.stream.look().test('name:in'): |
| 439 self.stream.skip(2) |
| 440 ops.append(nodes.Operand('notin', self.parse_add())) |
| 441 else: |
| 442 break |
| 443 lineno = self.stream.current.lineno |
| 444 if not ops: |
| 445 return expr |
| 446 return nodes.Compare(expr, ops, lineno=lineno) |
| 447 |
| 448 def parse_add(self): |
| 449 lineno = self.stream.current.lineno |
| 450 left = self.parse_sub() |
| 451 while self.stream.current.type == 'add': |
| 452 next(self.stream) |
| 453 right = self.parse_sub() |
| 454 left = nodes.Add(left, right, lineno=lineno) |
| 455 lineno = self.stream.current.lineno |
| 456 return left |
| 457 |
| 458 def parse_sub(self): |
| 459 lineno = self.stream.current.lineno |
| 460 left = self.parse_concat() |
| 461 while self.stream.current.type == 'sub': |
| 462 next(self.stream) |
| 463 right = self.parse_concat() |
| 464 left = nodes.Sub(left, right, lineno=lineno) |
| 465 lineno = self.stream.current.lineno |
| 466 return left |
| 467 |
| 468 def parse_concat(self): |
| 469 lineno = self.stream.current.lineno |
| 470 args = [self.parse_mul()] |
| 471 while self.stream.current.type == 'tilde': |
| 472 next(self.stream) |
| 473 args.append(self.parse_mul()) |
| 474 if len(args) == 1: |
| 475 return args[0] |
| 476 return nodes.Concat(args, lineno=lineno) |
| 477 |
| 478 def parse_mul(self): |
| 479 lineno = self.stream.current.lineno |
| 480 left = self.parse_div() |
| 481 while self.stream.current.type == 'mul': |
| 482 next(self.stream) |
| 483 right = self.parse_div() |
| 484 left = nodes.Mul(left, right, lineno=lineno) |
| 485 lineno = self.stream.current.lineno |
| 486 return left |
| 487 |
| 488 def parse_div(self): |
| 489 lineno = self.stream.current.lineno |
| 490 left = self.parse_floordiv() |
| 491 while self.stream.current.type == 'div': |
| 492 next(self.stream) |
| 493 right = self.parse_floordiv() |
| 494 left = nodes.Div(left, right, lineno=lineno) |
| 495 lineno = self.stream.current.lineno |
| 496 return left |
| 497 |
| 498 def parse_floordiv(self): |
| 499 lineno = self.stream.current.lineno |
| 500 left = self.parse_mod() |
| 501 while self.stream.current.type == 'floordiv': |
| 502 next(self.stream) |
| 503 right = self.parse_mod() |
| 504 left = nodes.FloorDiv(left, right, lineno=lineno) |
| 505 lineno = self.stream.current.lineno |
| 506 return left |
| 507 |
| 508 def parse_mod(self): |
| 509 lineno = self.stream.current.lineno |
| 510 left = self.parse_pow() |
| 511 while self.stream.current.type == 'mod': |
| 512 next(self.stream) |
| 513 right = self.parse_pow() |
| 514 left = nodes.Mod(left, right, lineno=lineno) |
| 515 lineno = self.stream.current.lineno |
| 516 return left |
| 517 |
| 518 def parse_pow(self): |
| 519 lineno = self.stream.current.lineno |
| 520 left = self.parse_unary() |
| 521 while self.stream.current.type == 'pow': |
| 522 next(self.stream) |
| 523 right = self.parse_unary() |
| 524 left = nodes.Pow(left, right, lineno=lineno) |
| 525 lineno = self.stream.current.lineno |
| 526 return left |
| 527 |
| 528 def parse_unary(self, with_filter=True): |
| 529 token_type = self.stream.current.type |
| 530 lineno = self.stream.current.lineno |
| 531 if token_type == 'sub': |
| 532 next(self.stream) |
| 533 node = nodes.Neg(self.parse_unary(False), lineno=lineno) |
| 534 elif token_type == 'add': |
| 535 next(self.stream) |
| 536 node = nodes.Pos(self.parse_unary(False), lineno=lineno) |
| 537 else: |
| 538 node = self.parse_primary() |
| 539 node = self.parse_postfix(node) |
| 540 if with_filter: |
| 541 node = self.parse_filter_expr(node) |
| 542 return node |
| 543 |
| 544 def parse_primary(self): |
| 545 token = self.stream.current |
| 546 if token.type == 'name': |
| 547 if token.value in ('true', 'false', 'True', 'False'): |
| 548 node = nodes.Const(token.value in ('true', 'True'), |
| 549 lineno=token.lineno) |
| 550 elif token.value in ('none', 'None'): |
| 551 node = nodes.Const(None, lineno=token.lineno) |
| 552 else: |
| 553 node = nodes.Name(token.value, 'load', lineno=token.lineno) |
| 554 next(self.stream) |
| 555 elif token.type == 'string': |
| 556 next(self.stream) |
| 557 buf = [token.value] |
| 558 lineno = token.lineno |
| 559 while self.stream.current.type == 'string': |
| 560 buf.append(self.stream.current.value) |
| 561 next(self.stream) |
| 562 node = nodes.Const(''.join(buf), lineno=lineno) |
| 563 elif token.type in ('integer', 'float'): |
| 564 next(self.stream) |
| 565 node = nodes.Const(token.value, lineno=token.lineno) |
| 566 elif token.type == 'lparen': |
| 567 next(self.stream) |
| 568 node = self.parse_tuple(explicit_parentheses=True) |
| 569 self.stream.expect('rparen') |
| 570 elif token.type == 'lbracket': |
| 571 node = self.parse_list() |
| 572 elif token.type == 'lbrace': |
| 573 node = self.parse_dict() |
| 574 else: |
| 575 self.fail("unexpected '%s'" % describe_token(token), token.lineno) |
| 576 return node |
| 577 |
| 578 def parse_tuple(self, simplified=False, with_condexpr=True, |
| 579 extra_end_rules=None, explicit_parentheses=False): |
| 580 """Works like `parse_expression` but if multiple expressions are |
| 581 delimited by a comma a :class:`~jinja2.nodes.Tuple` node is created. |
| 582 This method could also return a regular expression instead of a tuple |
| 583 if no commas where found. |
| 584 |
| 585 The default parsing mode is a full tuple. If `simplified` is `True` |
| 586 only names and literals are parsed. The `no_condexpr` parameter is |
| 587 forwarded to :meth:`parse_expression`. |
| 588 |
| 589 Because tuples do not require delimiters and may end in a bogus comma |
| 590 an extra hint is needed that marks the end of a tuple. For example |
| 591 for loops support tuples between `for` and `in`. In that case the |
| 592 `extra_end_rules` is set to ``['name:in']``. |
| 593 |
| 594 `explicit_parentheses` is true if the parsing was triggered by an |
| 595 expression in parentheses. This is used to figure out if an empty |
| 596 tuple is a valid expression or not. |
| 597 """ |
| 598 lineno = self.stream.current.lineno |
| 599 if simplified: |
| 600 parse = self.parse_primary |
| 601 elif with_condexpr: |
| 602 parse = self.parse_expression |
| 603 else: |
| 604 parse = lambda: self.parse_expression(with_condexpr=False) |
| 605 args = [] |
| 606 is_tuple = False |
| 607 while 1: |
| 608 if args: |
| 609 self.stream.expect('comma') |
| 610 if self.is_tuple_end(extra_end_rules): |
| 611 break |
| 612 args.append(parse()) |
| 613 if self.stream.current.type == 'comma': |
| 614 is_tuple = True |
| 615 else: |
| 616 break |
| 617 lineno = self.stream.current.lineno |
| 618 |
| 619 if not is_tuple: |
| 620 if args: |
| 621 return args[0] |
| 622 |
| 623 # if we don't have explicit parentheses, an empty tuple is |
| 624 # not a valid expression. This would mean nothing (literally |
| 625 # nothing) in the spot of an expression would be an empty |
| 626 # tuple. |
| 627 if not explicit_parentheses: |
| 628 self.fail('Expected an expression, got \'%s\'' % |
| 629 describe_token(self.stream.current)) |
| 630 |
| 631 return nodes.Tuple(args, 'load', lineno=lineno) |
| 632 |
| 633 def parse_list(self): |
| 634 token = self.stream.expect('lbracket') |
| 635 items = [] |
| 636 while self.stream.current.type != 'rbracket': |
| 637 if items: |
| 638 self.stream.expect('comma') |
| 639 if self.stream.current.type == 'rbracket': |
| 640 break |
| 641 items.append(self.parse_expression()) |
| 642 self.stream.expect('rbracket') |
| 643 return nodes.List(items, lineno=token.lineno) |
| 644 |
| 645 def parse_dict(self): |
| 646 token = self.stream.expect('lbrace') |
| 647 items = [] |
| 648 while self.stream.current.type != 'rbrace': |
| 649 if items: |
| 650 self.stream.expect('comma') |
| 651 if self.stream.current.type == 'rbrace': |
| 652 break |
| 653 key = self.parse_expression() |
| 654 self.stream.expect('colon') |
| 655 value = self.parse_expression() |
| 656 items.append(nodes.Pair(key, value, lineno=key.lineno)) |
| 657 self.stream.expect('rbrace') |
| 658 return nodes.Dict(items, lineno=token.lineno) |
| 659 |
| 660 def parse_postfix(self, node): |
| 661 while 1: |
| 662 token_type = self.stream.current.type |
| 663 if token_type == 'dot' or token_type == 'lbracket': |
| 664 node = self.parse_subscript(node) |
| 665 # calls are valid both after postfix expressions (getattr |
| 666 # and getitem) as well as filters and tests |
| 667 elif token_type == 'lparen': |
| 668 node = self.parse_call(node) |
| 669 else: |
| 670 break |
| 671 return node |
| 672 |
| 673 def parse_filter_expr(self, node): |
| 674 while 1: |
| 675 token_type = self.stream.current.type |
| 676 if token_type == 'pipe': |
| 677 node = self.parse_filter(node) |
| 678 elif token_type == 'name' and self.stream.current.value == 'is': |
| 679 node = self.parse_test(node) |
| 680 # calls are valid both after postfix expressions (getattr |
| 681 # and getitem) as well as filters and tests |
| 682 elif token_type == 'lparen': |
| 683 node = self.parse_call(node) |
| 684 else: |
| 685 break |
| 686 return node |
| 687 |
| 688 def parse_subscript(self, node): |
| 689 token = next(self.stream) |
| 690 if token.type == 'dot': |
| 691 attr_token = self.stream.current |
| 692 next(self.stream) |
| 693 if attr_token.type == 'name': |
| 694 return nodes.Getattr(node, attr_token.value, 'load', |
| 695 lineno=token.lineno) |
| 696 elif attr_token.type != 'integer': |
| 697 self.fail('expected name or number', attr_token.lineno) |
| 698 arg = nodes.Const(attr_token.value, lineno=attr_token.lineno) |
| 699 return nodes.Getitem(node, arg, 'load', lineno=token.lineno) |
| 700 if token.type == 'lbracket': |
| 701 priority_on_attribute = False |
| 702 args = [] |
| 703 while self.stream.current.type != 'rbracket': |
| 704 if args: |
| 705 self.stream.expect('comma') |
| 706 args.append(self.parse_subscribed()) |
| 707 self.stream.expect('rbracket') |
| 708 if len(args) == 1: |
| 709 arg = args[0] |
| 710 else: |
| 711 arg = nodes.Tuple(args, 'load', lineno=token.lineno) |
| 712 return nodes.Getitem(node, arg, 'load', lineno=token.lineno) |
| 713 self.fail('expected subscript expression', self.lineno) |
| 714 |
| 715 def parse_subscribed(self): |
| 716 lineno = self.stream.current.lineno |
| 717 |
| 718 if self.stream.current.type == 'colon': |
| 719 next(self.stream) |
| 720 args = [None] |
| 721 else: |
| 722 node = self.parse_expression() |
| 723 if self.stream.current.type != 'colon': |
| 724 return node |
| 725 next(self.stream) |
| 726 args = [node] |
| 727 |
| 728 if self.stream.current.type == 'colon': |
| 729 args.append(None) |
| 730 elif self.stream.current.type not in ('rbracket', 'comma'): |
| 731 args.append(self.parse_expression()) |
| 732 else: |
| 733 args.append(None) |
| 734 |
| 735 if self.stream.current.type == 'colon': |
| 736 next(self.stream) |
| 737 if self.stream.current.type not in ('rbracket', 'comma'): |
| 738 args.append(self.parse_expression()) |
| 739 else: |
| 740 args.append(None) |
| 741 else: |
| 742 args.append(None) |
| 743 |
| 744 return nodes.Slice(lineno=lineno, *args) |
| 745 |
| 746 def parse_call(self, node): |
| 747 token = self.stream.expect('lparen') |
| 748 args = [] |
| 749 kwargs = [] |
| 750 dyn_args = dyn_kwargs = None |
| 751 require_comma = False |
| 752 |
| 753 def ensure(expr): |
| 754 if not expr: |
| 755 self.fail('invalid syntax for function call expression', |
| 756 token.lineno) |
| 757 |
| 758 while self.stream.current.type != 'rparen': |
| 759 if require_comma: |
| 760 self.stream.expect('comma') |
| 761 # support for trailing comma |
| 762 if self.stream.current.type == 'rparen': |
| 763 break |
| 764 if self.stream.current.type == 'mul': |
| 765 ensure(dyn_args is None and dyn_kwargs is None) |
| 766 next(self.stream) |
| 767 dyn_args = self.parse_expression() |
| 768 elif self.stream.current.type == 'pow': |
| 769 ensure(dyn_kwargs is None) |
| 770 next(self.stream) |
| 771 dyn_kwargs = self.parse_expression() |
| 772 else: |
| 773 ensure(dyn_args is None and dyn_kwargs is None) |
| 774 if self.stream.current.type == 'name' and \ |
| 775 self.stream.look().type == 'assign': |
| 776 key = self.stream.current.value |
| 777 self.stream.skip(2) |
| 778 value = self.parse_expression() |
| 779 kwargs.append(nodes.Keyword(key, value, |
| 780 lineno=value.lineno)) |
| 781 else: |
| 782 ensure(not kwargs) |
| 783 args.append(self.parse_expression()) |
| 784 |
| 785 require_comma = True |
| 786 self.stream.expect('rparen') |
| 787 |
| 788 if node is None: |
| 789 return args, kwargs, dyn_args, dyn_kwargs |
| 790 return nodes.Call(node, args, kwargs, dyn_args, dyn_kwargs, |
| 791 lineno=token.lineno) |
| 792 |
| 793 def parse_filter(self, node, start_inline=False): |
| 794 while self.stream.current.type == 'pipe' or start_inline: |
| 795 if not start_inline: |
| 796 next(self.stream) |
| 797 token = self.stream.expect('name') |
| 798 name = token.value |
| 799 while self.stream.current.type == 'dot': |
| 800 next(self.stream) |
| 801 name += '.' + self.stream.expect('name').value |
| 802 if self.stream.current.type == 'lparen': |
| 803 args, kwargs, dyn_args, dyn_kwargs = self.parse_call(None) |
| 804 else: |
| 805 args = [] |
| 806 kwargs = [] |
| 807 dyn_args = dyn_kwargs = None |
| 808 node = nodes.Filter(node, name, args, kwargs, dyn_args, |
| 809 dyn_kwargs, lineno=token.lineno) |
| 810 start_inline = False |
| 811 return node |
| 812 |
| 813 def parse_test(self, node): |
| 814 token = next(self.stream) |
| 815 if self.stream.current.test('name:not'): |
| 816 next(self.stream) |
| 817 negated = True |
| 818 else: |
| 819 negated = False |
| 820 name = self.stream.expect('name').value |
| 821 while self.stream.current.type == 'dot': |
| 822 next(self.stream) |
| 823 name += '.' + self.stream.expect('name').value |
| 824 dyn_args = dyn_kwargs = None |
| 825 kwargs = [] |
| 826 if self.stream.current.type == 'lparen': |
| 827 args, kwargs, dyn_args, dyn_kwargs = self.parse_call(None) |
| 828 elif self.stream.current.type in ('name', 'string', 'integer', |
| 829 'float', 'lparen', 'lbracket', |
| 830 'lbrace') and not \ |
| 831 self.stream.current.test_any('name:else', 'name:or', |
| 832 'name:and'): |
| 833 if self.stream.current.test('name:is'): |
| 834 self.fail('You cannot chain multiple tests with is') |
| 835 args = [self.parse_expression()] |
| 836 else: |
| 837 args = [] |
| 838 node = nodes.Test(node, name, args, kwargs, dyn_args, |
| 839 dyn_kwargs, lineno=token.lineno) |
| 840 if negated: |
| 841 node = nodes.Not(node, lineno=token.lineno) |
| 842 return node |
| 843 |
| 844 def subparse(self, end_tokens=None): |
| 845 body = [] |
| 846 data_buffer = [] |
| 847 add_data = data_buffer.append |
| 848 |
| 849 if end_tokens is not None: |
| 850 self._end_token_stack.append(end_tokens) |
| 851 |
| 852 def flush_data(): |
| 853 if data_buffer: |
| 854 lineno = data_buffer[0].lineno |
| 855 body.append(nodes.Output(data_buffer[:], lineno=lineno)) |
| 856 del data_buffer[:] |
| 857 |
| 858 try: |
| 859 while self.stream: |
| 860 token = self.stream.current |
| 861 if token.type == 'data': |
| 862 if token.value: |
| 863 add_data(nodes.TemplateData(token.value, |
| 864 lineno=token.lineno)) |
| 865 next(self.stream) |
| 866 elif token.type == 'variable_begin': |
| 867 next(self.stream) |
| 868 add_data(self.parse_tuple(with_condexpr=True)) |
| 869 self.stream.expect('variable_end') |
| 870 elif token.type == 'block_begin': |
| 871 flush_data() |
| 872 next(self.stream) |
| 873 if end_tokens is not None and \ |
| 874 self.stream.current.test_any(*end_tokens): |
| 875 return body |
| 876 rv = self.parse_statement() |
| 877 if isinstance(rv, list): |
| 878 body.extend(rv) |
| 879 else: |
| 880 body.append(rv) |
| 881 self.stream.expect('block_end') |
| 882 else: |
| 883 raise AssertionError('internal parsing error') |
| 884 |
| 885 flush_data() |
| 886 finally: |
| 887 if end_tokens is not None: |
| 888 self._end_token_stack.pop() |
| 889 |
| 890 return body |
| 891 |
| 892 def parse(self): |
| 893 """Parse the whole template into a `Template` node.""" |
| 894 result = nodes.Template(self.subparse(), lineno=1) |
| 895 result.set_environment(self.environment) |
| 896 return result |
OLD | NEW |