| 1 | #!/usr/bin/env python3 |
| 2 | r""" |
| 3 | PPT Master - Microsoft 365 LaTeX Formula Parser |
| 4 | |
| 5 | Parse the documented Microsoft 365 LaTeX import profile into the internal |
| 6 | native-formula AST. Unknown commands remain fail-closed. |
| 7 | |
| 8 | See references/native-formula.md for the owning authoring contract. |
| 9 | |
| 10 | Usage: |
| 11 | Import parse_latex_formula() from the native formula compiler facade. |
| 12 | |
| 13 | Examples: |
| 14 | parse_latex_formula(r"\binom{n}{k}", display=True) |
| 15 | |
| 16 | Dependencies: |
| 17 | None (only uses standard library and local PPT Master modules) |
| 18 | """ |
| 19 | |
| 20 | from __future__ import annotations |
| 21 | |
| 22 | import re |
| 23 | from dataclasses import dataclass |
| 24 | |
| 25 | from .formula_ast import ( |
| 26 | Accent, |
| 27 | AlignmentPoint, |
| 28 | Bar, |
| 29 | BorderBox, |
| 30 | Delimiter, |
| 31 | EquationArray, |
| 32 | Fraction, |
| 33 | Function, |
| 34 | GroupChar, |
| 35 | Limit, |
| 36 | Matrix, |
| 37 | Nary, |
| 38 | Node, |
| 39 | OperatorEmulator, |
| 40 | Phantom, |
| 41 | Prescript, |
| 42 | Radical, |
| 43 | RunStyle, |
| 44 | Script, |
| 45 | Sequence, |
| 46 | Styled, |
| 47 | Text, |
| 48 | append_child, |
| 49 | is_empty, |
| 50 | merge_run_styles, |
| 51 | ) |
| 52 | from .formula_profile import ( |
| 53 | ACCENT_COMMANDS, |
| 54 | BARE_DELIMITER_COMMAND_PAIRS, |
| 55 | COLOR_NAMES, |
| 56 | DELIMITER_COMMANDS, |
| 57 | DISCARDED_ARGUMENT_COMMANDS, |
| 58 | EQUATION_ARRAY_ENVIRONMENTS, |
| 59 | GREEK_SYMBOLS, |
| 60 | LIMIT_FUNCTIONS, |
| 61 | MATRIX_ENVIRONMENTS, |
| 62 | NARY_COMMANDS, |
| 63 | NEGATED_SYMBOLS, |
| 64 | NO_OUTPUT_COMMANDS, |
| 65 | OPERATOR_BOUNDARY_COMMANDS, |
| 66 | SPACING_COMMANDS, |
| 67 | STANDARD_FUNCTIONS, |
| 68 | SYMBOL_COMMANDS, |
| 69 | UNSUPPORTED_COMMANDS, |
| 70 | VARIANT_UPPERCASE_GREEK, |
| 71 | ) |
| 72 | |
| 73 | |
| 74 | _MAX_PARSE_DEPTH = 128 |
| 75 | _MAX_MACRO_EXPANSIONS = 500 |
| 76 | _MAX_EXPANDED_LENGTH = 1_048_576 |
| 77 | _ENVIRONMENT_NAME_RE = re.compile(r"[A-Za-z]+\*?") |
| 78 | _COLOR_HEX_RE = re.compile(r"#[0-9A-Fa-f]{6}") |
| 79 | _LENGTH_RE = re.compile( |
| 80 | r"([+-]?(?:\d+(?:\.\d*)?|\.\d+))\s*(mu|em|ex|pt)", |
| 81 | re.IGNORECASE, |
| 82 | ) |
| 83 | _BIG_DELIMITER_RE = re.compile( |
| 84 | r"\\(?:big|Big|bigg|Bigg)([lrm]?)(?![A-Za-z])\s*" |
| 85 | r"(\\[A-Za-z]+|\\[{}|]|[()\[\]{}|.])" |
| 86 | ) |
| 87 | _BIG_LEFT_COMMAND = "pptmasterbigleft" |
| 88 | _BIG_RIGHT_COMMAND = "pptmasterbigright" |
| 89 | _BIG_MIDDLE_COMMAND = "pptmasterbigmiddle" |
| 90 | _BIG_SYMMETRIC_COMMAND = "pptmasterbigsymmetric" |
| 91 | _MIDDLE_DELIMITER_COMMANDS = ("middle", _BIG_MIDDLE_COMMAND) |
| 92 | _RIGHT_DELIMITER_COMMANDS = ("right", _BIG_RIGHT_COMMAND) |
| 93 | _WHITE_OPEN_RE = re.compile( |
| 94 | r"(?:(?:\\left)?(?:\[|\\lbrack))\\!" |
| 95 | r"(?:(?:\\left)?(?:\[|\\lbrack))" |
| 96 | ) |
| 97 | _WHITE_CLOSE_RE = re.compile( |
| 98 | r"(?:(?:\\right)?(?:\]|\\rbrack))\\!" |
| 99 | r"(?:(?:\\right)?(?:\]|\\rbrack))" |
| 100 | ) |
| 101 | |
| 102 | _ROMAN_STYLE = RunStyle(style="p", is_default=True) |
| 103 | _TEXT_STYLE = RunStyle(normal=True) |
| 104 | _MATH_MODE_RESET_STYLE = RunStyle( |
| 105 | normal=False, |
| 106 | bold=False, |
| 107 | italic=False, |
| 108 | typeface="", |
| 109 | ) |
| 110 | _SPACING_STYLE = RunStyle() |
| 111 | _PLAIN_OPERATOR_CHARS = frozenset("+−*/=<>±∓×÷⋅,;:!?") |
| 112 | _INFIX_FRACTIONS = frozenset({"over", "atop", "choose", "brace", "brack"}) |
| 113 | |
| 114 | _STYLE_WRAPPERS = { |
| 115 | "mathrm": RunStyle(style="p"), |
| 116 | "mathbf": RunStyle(style="b"), |
| 117 | "mathit": RunStyle(style="i"), |
| 118 | "mathsf": RunStyle(style="p", script="sans-serif"), |
| 119 | "mathtt": RunStyle(style="p", script="monospace"), |
| 120 | "mathbb": RunStyle(style="p", script="double-struck"), |
| 121 | "Bbb": RunStyle(style="p", script="double-struck"), |
| 122 | "mathcal": RunStyle(style="p", script="script"), |
| 123 | "mathscr": RunStyle(style="p", script="script"), |
| 124 | "mathfrak": RunStyle(style="p", script="fraktur"), |
| 125 | "boldsymbol": RunStyle(style="bi"), |
| 126 | "bm": RunStyle(style="bi"), |
| 127 | "text": _TEXT_STYLE, |
| 128 | "textrm": _TEXT_STYLE, |
| 129 | "textnormal": _TEXT_STYLE, |
| 130 | "textbf": RunStyle(normal=True, bold=True), |
| 131 | "textit": RunStyle(normal=True, italic=True), |
| 132 | "emph": RunStyle(normal=True, italic=True), |
| 133 | "textsf": RunStyle(normal=True, typeface="Arial"), |
| 134 | "texttt": RunStyle(normal=True, typeface="Courier New"), |
| 135 | "mbox": _TEXT_STYLE, |
| 136 | "hbox": _TEXT_STYLE, |
| 137 | } |
| 138 | |
| 139 | _DECLARATION_STYLES = { |
| 140 | "rm": RunStyle(style="p"), |
| 141 | "bf": RunStyle(style="b"), |
| 142 | "it": RunStyle(style="i"), |
| 143 | "cal": RunStyle(style="p", script="script"), |
| 144 | "frak": RunStyle(style="p", script="fraktur"), |
| 145 | "sf": RunStyle(style="p", script="sans-serif"), |
| 146 | "tt": RunStyle(style="p", script="monospace"), |
| 147 | } |
| 148 | |
| 149 | _OVER_UNDER_COMMANDS = { |
| 150 | "overbrace": ("⏞", "top", "bot"), |
| 151 | "underbrace": ("⏟", "bot", "top"), |
| 152 | "underrightarrow": ("→", "bot", "top"), |
| 153 | "underleftarrow": ("←", "bot", "top"), |
| 154 | "underleftrightarrow": ("↔", "bot", "top"), |
| 155 | } |
| 156 | |
| 157 | _OVER_ARROW_COMMANDS = { |
| 158 | "overrightarrow": "→", |
| 159 | "overleftarrow": "←", |
| 160 | "overleftrightarrow": "↔", |
| 161 | } |
| 162 | |
| 163 | |
| 164 | class FormulaCompileError(ValueError): |
| 165 | """Raised when formula source violates the Microsoft 365 profile.""" |
| 166 | |
| 167 | |
| 168 | @dataclass(frozen=True) |
| 169 | class _Macro: |
| 170 | parameter_count: int |
| 171 | body: str |
| 172 | |
| 173 | |
| 174 | def _is_command_letter(char: str) -> bool: |
| 175 | return char.isascii() and char.isalpha() |
| 176 | |
| 177 | |
| 178 | def _xml_character_allowed(char: str) -> bool: |
| 179 | codepoint = ord(char) |
| 180 | return ( |
| 181 | codepoint in {0x09, 0x0A, 0x0D} |
| 182 | or 0x20 <= codepoint <= 0xD7FF |
| 183 | or 0xE000 <= codepoint <= 0xFFFD |
| 184 | or 0x10000 <= codepoint <= 0x10FFFF |
| 185 | ) |
| 186 | |
| 187 | |
| 188 | def _read_control_word(source: str, position: int) -> tuple[str, int]: |
| 189 | if position >= len(source) or source[position] != "\\": |
| 190 | raise FormulaCompileError("Expected a LaTeX control word") |
| 191 | position += 1 |
| 192 | start = position |
| 193 | while position < len(source) and _is_command_letter(source[position]): |
| 194 | position += 1 |
| 195 | if position == start: |
| 196 | raise FormulaCompileError("Expected a LaTeX control word") |
| 197 | return source[start:position], position |
| 198 | |
| 199 | |
| 200 | def _skip_whitespace(source: str, position: int) -> int: |
| 201 | while position < len(source) and source[position].isspace(): |
| 202 | position += 1 |
| 203 | return position |
| 204 | |
| 205 | |
| 206 | def _read_raw_group(source: str, position: int) -> tuple[str, int]: |
| 207 | position = _skip_whitespace(source, position) |
| 208 | if position >= len(source) or source[position] != "{": |
| 209 | raise FormulaCompileError("Expected a braced LaTeX group") |
| 210 | depth = 1 |
| 211 | cursor = position + 1 |
| 212 | start = cursor |
| 213 | while cursor < len(source): |
| 214 | char = source[cursor] |
| 215 | if char == "\\": |
| 216 | cursor += 2 |
| 217 | continue |
| 218 | if char == "{": |
| 219 | depth += 1 |
| 220 | elif char == "}": |
| 221 | depth -= 1 |
| 222 | if depth == 0: |
| 223 | return source[start:cursor], cursor + 1 |
| 224 | cursor += 1 |
| 225 | raise FormulaCompileError("Unclosed braced LaTeX group") |
| 226 | |
| 227 | |
| 228 | def _read_optional_integer(source: str, position: int) -> tuple[int | None, int]: |
| 229 | position = _skip_whitespace(source, position) |
| 230 | if position >= len(source) or source[position] != "[": |
| 231 | return None, position |
| 232 | closing = source.find("]", position + 1) |
| 233 | if closing < 0: |
| 234 | raise FormulaCompileError("Unclosed optional macro parameter count") |
| 235 | raw = source[position + 1:closing].strip() |
| 236 | if not raw.isdigit() or not 0 <= int(raw) <= 9: |
| 237 | raise FormulaCompileError("Macro parameter count must be between 0 and 9") |
| 238 | return int(raw), closing + 1 |
| 239 | |
| 240 | |
| 241 | def _collect_macros(source: str) -> tuple[str, dict[str, _Macro]]: |
| 242 | macros: dict[str, _Macro] = {} |
| 243 | output: list[str] = [] |
| 244 | position = 0 |
| 245 | while position < len(source): |
| 246 | if source[position] != "\\": |
| 247 | output.append(source[position]) |
| 248 | position += 1 |
| 249 | continue |
| 250 | try: |
| 251 | command, command_end = _read_control_word(source, position) |
| 252 | except FormulaCompileError: |
| 253 | output.append(source[position]) |
| 254 | position += 1 |
| 255 | continue |
| 256 | if command not in {"newcommand", "renewcommand", "def"}: |
| 257 | output.append(source[position:command_end]) |
| 258 | position = command_end |
| 259 | continue |
| 260 | |
| 261 | cursor = _skip_whitespace(source, command_end) |
| 262 | if command in {"newcommand", "renewcommand"}: |
| 263 | name_group, cursor = _read_raw_group(source, cursor) |
| 264 | name_group = name_group.strip() |
| 265 | if not re.fullmatch(r"\\[A-Za-z]+", name_group): |
| 266 | raise FormulaCompileError( |
| 267 | f"\\{command} requires one control-word macro name" |
| 268 | ) |
| 269 | parameter_count, cursor = _read_optional_integer(source, cursor) |
| 270 | body, cursor = _read_raw_group(source, cursor) |
| 271 | count = parameter_count or 0 |
| 272 | if re.search(r"#(?:0|[1-9][0-9])", body): |
| 273 | raise FormulaCompileError("Macro body uses an invalid parameter number") |
| 274 | macros[name_group[1:]] = _Macro(count, body) |
| 275 | else: |
| 276 | if cursor >= len(source) or source[cursor] != "\\": |
| 277 | raise FormulaCompileError("\\def requires one control-word macro name") |
| 278 | name, cursor = _read_control_word(source, cursor) |
| 279 | parameters: list[int] = [] |
| 280 | cursor = _skip_whitespace(source, cursor) |
| 281 | while cursor < len(source) and source[cursor] == "#": |
| 282 | if cursor + 1 >= len(source) or source[cursor + 1] not in "123456789": |
| 283 | raise FormulaCompileError("\\def parameters must use #1 through #9") |
| 284 | parameters.append(int(source[cursor + 1])) |
| 285 | cursor = _skip_whitespace(source, cursor + 2) |
| 286 | expected = list(range(1, len(parameters) + 1)) |
| 287 | if parameters != expected: |
| 288 | raise FormulaCompileError("\\def parameters must be consecutive from #1") |
| 289 | body, cursor = _read_raw_group(source, cursor) |
| 290 | macros[name] = _Macro(len(parameters), body) |
| 291 | position = cursor |
| 292 | return "".join(output), macros |
| 293 | |
| 294 | |
| 295 | def _read_macro_argument(source: str, position: int) -> tuple[str, int]: |
| 296 | position = _skip_whitespace(source, position) |
| 297 | if position >= len(source): |
| 298 | raise FormulaCompileError("Macro invocation is missing an argument") |
| 299 | if source[position] == "{": |
| 300 | return _read_raw_group(source, position) |
| 301 | if source[position] == "\\": |
| 302 | if position + 1 >= len(source): |
| 303 | raise FormulaCompileError("Macro invocation ends with a backslash") |
| 304 | if _is_command_letter(source[position + 1]): |
| 305 | _, end = _read_control_word(source, position) |
| 306 | return source[position:end], end |
| 307 | return source[position:position + 2], position + 2 |
| 308 | return source[position], position + 1 |
| 309 | |
| 310 | |
| 311 | def _expand_macros(source: str, macros: dict[str, _Macro]) -> str: |
| 312 | if not macros: |
| 313 | return source |
| 314 | expansion_count = 0 |
| 315 | while True: |
| 316 | output: list[str] = [] |
| 317 | position = 0 |
| 318 | replaced = False |
| 319 | while position < len(source): |
| 320 | if source[position] != "\\" or position + 1 >= len(source): |
| 321 | output.append(source[position]) |
| 322 | position += 1 |
| 323 | continue |
| 324 | if not _is_command_letter(source[position + 1]): |
| 325 | output.append(source[position:position + 2]) |
| 326 | position += 2 |
| 327 | continue |
| 328 | command, cursor = _read_control_word(source, position) |
| 329 | macro = macros.get(command) |
| 330 | if macro is None: |
| 331 | output.append(source[position:cursor]) |
| 332 | position = cursor |
| 333 | continue |
| 334 | arguments: list[str] = [] |
| 335 | for _ in range(macro.parameter_count): |
| 336 | argument, cursor = _read_macro_argument(source, cursor) |
| 337 | arguments.append(argument) |
| 338 | body = macro.body |
| 339 | for index, argument in enumerate(arguments, start=1): |
| 340 | body = body.replace(f"#{index}", argument) |
| 341 | output.append(body) |
| 342 | position = cursor |
| 343 | expansion_count += 1 |
| 344 | if expansion_count > _MAX_MACRO_EXPANSIONS: |
| 345 | raise FormulaCompileError( |
| 346 | f"Formula exceeds the {_MAX_MACRO_EXPANSIONS}-macro expansion limit" |
| 347 | ) |
| 348 | replaced = True |
| 349 | source = "".join(output) |
| 350 | if len(source) > _MAX_EXPANDED_LENGTH: |
| 351 | raise FormulaCompileError( |
| 352 | f"Expanded formula exceeds the {_MAX_EXPANDED_LENGTH}-character limit" |
| 353 | ) |
| 354 | if not replaced: |
| 355 | return source |
| 356 | |
| 357 | |
| 358 | def _strip_outer_delimiters(source: str) -> str: |
| 359 | pairs = (("$$", "$$"), ("$", "$"), ("\\(", "\\)"), ("\\[", "\\]")) |
| 360 | for opener, closer in pairs: |
| 361 | if source.startswith(opener): |
| 362 | if not source.endswith(closer) or len(source) <= len(opener) + len(closer): |
| 363 | raise FormulaCompileError(f"Unclosed outer LaTeX delimiter {opener!r}") |
| 364 | return source[len(opener):-len(closer)].strip() |
| 365 | return source |
| 366 | |
| 367 | |
| 368 | def _normalize_big_delimiters(source: str) -> str: |
| 369 | def replace(match: re.Match[str]) -> str: |
| 370 | direction = match.group(1) |
| 371 | delimiter = match.group(2) |
| 372 | if direction: |
| 373 | command = { |
| 374 | "l": _BIG_LEFT_COMMAND, |
| 375 | "r": _BIG_RIGHT_COMMAND, |
| 376 | "m": _BIG_MIDDLE_COMMAND, |
| 377 | }[direction] |
| 378 | return f"\\{command}{delimiter}" |
| 379 | openers = { |
| 380 | "(", "[", "{", ".", r"\{", r"\lbrace", r"\langle", r"\lfloor", |
| 381 | r"\lceil", r"\lvert", r"\lVert", r"\lbrack", |
| 382 | } |
| 383 | closers = { |
| 384 | ")", "]", "}", r"\}", r"\rbrace", r"\rangle", r"\rfloor", |
| 385 | r"\rceil", r"\rvert", r"\rVert", r"\rbrack", |
| 386 | } |
| 387 | symmetric = {"|", r"\|", r"\vert", r"\Vert"} |
| 388 | if delimiter in openers: |
| 389 | return f"\\{_BIG_LEFT_COMMAND}{delimiter}" |
| 390 | if delimiter in closers: |
| 391 | return f"\\{_BIG_RIGHT_COMMAND}{delimiter}" |
| 392 | if delimiter in symmetric: |
| 393 | return f"\\{_BIG_SYMMETRIC_COMMAND}{delimiter}" |
| 394 | return delimiter |
| 395 | |
| 396 | return _BIG_DELIMITER_RE.sub(replace, source) |
| 397 | |
| 398 | |
| 399 | def _normalize_white_brackets(source: str) -> str: |
| 400 | source = _WHITE_OPEN_RE.sub(r"\\left⟦", source) |
| 401 | return _WHITE_CLOSE_RE.sub(r"\\right⟧", source) |
| 402 | |
| 403 | |
| 404 | def _prepare_source(source: str) -> str: |
| 405 | source = _strip_outer_delimiters(source.strip()) |
| 406 | if "%" in source: |
| 407 | position = 0 |
| 408 | while position < len(source): |
| 409 | if source[position] == "%" and (position == 0 or source[position - 1] != "\\"): |
| 410 | raise FormulaCompileError("Unescaped % comments are outside the Office profile") |
| 411 | position += 1 |
| 412 | without_definitions, macros = _collect_macros(source) |
| 413 | expanded = _expand_macros(without_definitions, macros) |
| 414 | return _normalize_white_brackets(_normalize_big_delimiters(expanded)).strip() |
| 415 | |
| 416 | |
| 417 | def _space_from_length(raw: str) -> str: |
| 418 | match = _LENGTH_RE.fullmatch(raw.strip()) |
| 419 | if match is None: |
| 420 | raise FormulaCompileError(f"Unsupported math spacing length: {raw!r}") |
| 421 | amount = float(match.group(1)) |
| 422 | unit = match.group(2).lower() |
| 423 | multiplier = {"mu": 1.0, "em": 18.0, "ex": 9.0, "pt": 1.8}[unit] |
| 424 | mu = min(2160.0, amount * multiplier) |
| 425 | if mu <= 0: |
| 426 | return "\u200b" |
| 427 | whole_em = int(mu // 18) |
| 428 | remainder = mu - whole_em * 18 |
| 429 | output = "\u2003" * whole_em |
| 430 | if remainder >= 14: |
| 431 | output += "\u2003" |
| 432 | elif remainder >= 9: |
| 433 | output += "\u2002" |
| 434 | elif remainder >= 4.5: |
| 435 | output += "\u2004" |
| 436 | elif remainder >= 3.5: |
| 437 | output += "\u205f" |
| 438 | elif remainder >= 2: |
| 439 | output += "\u2009" |
| 440 | elif remainder > 0: |
| 441 | output += "\u200b" |
| 442 | return output or "\u200b" |
| 443 | |
| 444 | |
| 445 | class _LatexParser: |
| 446 | """Parse one prepared formula source under the Office import profile.""" |
| 447 | |
| 448 | def __init__( |
| 449 | self, |
| 450 | source: str, |
| 451 | *, |
| 452 | display: bool, |
| 453 | text_mode: bool = False, |
| 454 | inherited_style: RunStyle | None = None, |
| 455 | ) -> None: |
| 456 | self.source = source |
| 457 | self.position = 0 |
| 458 | self.depth = 0 |
| 459 | self.display = display |
| 460 | self.text_mode_depth = 1 if text_mode else 0 |
| 461 | self.current_style = inherited_style |
| 462 | self.environment_stack: list[str] = [] |
| 463 | |
| 464 | def parse(self) -> Sequence: |
| 465 | result = self._parse_sequence() |
| 466 | if self.position != len(self.source): |
| 467 | self._fail("Unexpected trailing formula source") |
| 468 | if is_empty(result): |
| 469 | self._fail("Formula is empty") |
| 470 | return result |
| 471 | |
| 472 | def _parse_sequence( |
| 473 | self, |
| 474 | *, |
| 475 | terminator: str | None = None, |
| 476 | stop_commands: frozenset[str] = frozenset(), |
| 477 | stop_at_environment_boundary: bool = False, |
| 478 | ) -> Sequence: |
| 479 | children: list[Node] = [] |
| 480 | while self.position < len(self.source): |
| 481 | if terminator is not None and self.source[self.position] == terminator: |
| 482 | self.position += 1 |
| 483 | return Sequence(tuple(children)) |
| 484 | if any(self._at_control_word(command) for command in stop_commands): |
| 485 | return Sequence(tuple(children)) |
| 486 | if stop_at_environment_boundary and self._at_environment_boundary(): |
| 487 | return Sequence(tuple(children)) |
| 488 | |
| 489 | char = self.source[self.position] |
| 490 | if char == "}": |
| 491 | self._fail("Unexpected closing group") |
| 492 | if char == "&": |
| 493 | self._fail("Alignment marker '&' is only valid inside an environment") |
| 494 | if char in "^_": |
| 495 | append_child(children, self._parse_prescript()) |
| 496 | continue |
| 497 | infix = self._current_infix_command() |
| 498 | if infix is not None: |
| 499 | if not children: |
| 500 | self._fail(f"Infix fraction \\{infix} has no numerator") |
| 501 | self._consume_control_word(infix) |
| 502 | right = self._parse_nested_sequence( |
| 503 | terminator=terminator, |
| 504 | stop_commands=stop_commands, |
| 505 | stop_at_environment_boundary=stop_at_environment_boundary, |
| 506 | ) |
| 507 | if is_empty(right): |
| 508 | self._fail(f"Infix fraction \\{infix} has no denominator") |
| 509 | left = Sequence(tuple(children)) |
| 510 | fraction = Fraction( |
| 511 | numerator=left, |
| 512 | denominator=right, |
| 513 | kind="bar" if infix == "over" else "noBar", |
| 514 | ) |
| 515 | if infix in {"choose", "brace", "brack"}: |
| 516 | delimiters = { |
| 517 | "choose": ("(", ")"), |
| 518 | "brace": ("{", "}"), |
| 519 | "brack": ("[", "]"), |
| 520 | }[infix] |
| 521 | return Sequence((Delimiter(*delimiters, (Sequence((fraction,)),)),)) |
| 522 | return Sequence((fraction,)) |
| 523 | |
| 524 | atom = self._parse_complete_atom() |
| 525 | append_child(children, atom) |
| 526 | |
| 527 | if terminator is not None: |
| 528 | self._fail(f"Unclosed group; expected {terminator!r}") |
| 529 | return Sequence(tuple(children)) |
| 530 | |
| 531 | def _parse_atom(self) -> Node: |
| 532 | char = self.source[self.position] |
| 533 | if char.isspace(): |
| 534 | while self.position < len(self.source) and self.source[self.position].isspace(): |
| 535 | self.position += 1 |
| 536 | return self._styled_text(" ") if self.text_mode_depth else Sequence(()) |
| 537 | if char == "{": |
| 538 | return self._parse_group() |
| 539 | if char == "\\": |
| 540 | return self._parse_command() |
| 541 | if char in "([|": |
| 542 | return self._parse_or_literal_character_delimiter(char) |
| 543 | if char == "$": |
| 544 | if not self.text_mode_depth: |
| 545 | self._fail("Math delimiters are only allowed around the complete marker source") |
| 546 | return self._parse_text_embedded_math("$", "$") |
| 547 | if char in "#%": |
| 548 | self._fail(f"Unsupported TeX syntax character {char!r}") |
| 549 | if ord(char) < 32: |
| 550 | self._fail("Unsupported control character") |
| 551 | |
| 552 | self.position += 1 |
| 553 | if self.text_mode_depth: |
| 554 | return self._styled_text(char) |
| 555 | if char == "-": |
| 556 | char = "−" |
| 557 | elif char == "~": |
| 558 | return self._styled_text("\u00a0", _SPACING_STYLE) |
| 559 | style = _ROMAN_STYLE if char in _PLAIN_OPERATOR_CHARS else None |
| 560 | return self._styled_text(char, style) |
| 561 | |
| 562 | def _parse_command(self) -> Node: |
| 563 | command_start = self.position |
| 564 | self.position += 1 |
| 565 | if self.position >= len(self.source): |
| 566 | self._fail("Trailing backslash", position=command_start) |
| 567 | |
| 568 | char = self.source[self.position] |
| 569 | if not _is_command_letter(char): |
| 570 | self.position += 1 |
| 571 | if char == "\\": |
| 572 | self._fail( |
| 573 | "Row separator '\\\\' is only valid inside an environment", |
| 574 | position=command_start, |
| 575 | ) |
| 576 | if char == "|": |
| 577 | paired = self._try_symmetric_command_delimiter(command_start) |
| 578 | if paired is not None: |
| 579 | return paired |
| 580 | return self._styled_text("‖", _ROMAN_STYLE) |
| 581 | if char == "(" and self.text_mode_depth: |
| 582 | return self._parse_text_embedded_math("\\(", "\\)", opened=True) |
| 583 | if char == "{": |
| 584 | paired = self._try_escaped_brace_delimiter() |
| 585 | if paired is not None: |
| 586 | return paired |
| 587 | escaped = { |
| 588 | "{": "{", |
| 589 | "}": "}", |
| 590 | "_": "_", |
| 591 | "%": "%", |
| 592 | "#": "#", |
| 593 | "$": "$", |
| 594 | "&": "&", |
| 595 | } |
| 596 | if char in escaped: |
| 597 | return self._styled_text( |
| 598 | escaped[char], |
| 599 | literal=char == "&", |
| 600 | ) |
| 601 | if char in SPACING_COMMANDS: |
| 602 | return self._styled_text(SPACING_COMMANDS[char], _SPACING_STYLE) |
| 603 | self._fail(f"Unsupported control symbol \\{char}", position=command_start) |
| 604 | |
| 605 | command = self._read_control_word_body() |
| 606 | self._skip_whitespace() |
| 607 | if command in UNSUPPORTED_COMMANDS: |
| 608 | self._fail(f"Unsupported LaTeX command \\{command}", position=command_start) |
| 609 | if command in {"vert", "Vert"}: |
| 610 | paired = self._try_symmetric_named_delimiter(command) |
| 611 | if paired is not None: |
| 612 | return paired |
| 613 | if command in GREEK_SYMBOLS: |
| 614 | style = None |
| 615 | if command[:1].isupper() and command not in VARIANT_UPPERCASE_GREEK: |
| 616 | style = _ROMAN_STYLE |
| 617 | return self._styled_text(GREEK_SYMBOLS[command], style) |
| 618 | if command in SYMBOL_COMMANDS: |
| 619 | return self._styled_text(SYMBOL_COMMANDS[command], _ROMAN_STYLE) |
| 620 | if command in DELIMITER_COMMANDS: |
| 621 | paired = self._try_command_delimiter(command, command_start) |
| 622 | if paired is not None: |
| 623 | return paired |
| 624 | return self._styled_text(DELIMITER_COMMANDS[command], _ROMAN_STYLE) |
| 625 | if command in NARY_COMMANDS: |
| 626 | symbol, category = NARY_COMMANDS[command] |
| 627 | return Nary(symbol=symbol, category=category) |
| 628 | if command in STANDARD_FUNCTIONS: |
| 629 | return Function(name=self._roman_name(command)) |
| 630 | if command in LIMIT_FUNCTIONS: |
| 631 | return Function(name=self._roman_name(command), limit_style=True) |
| 632 | if command == "operatorname": |
| 633 | name = self._parse_required_argument("operator name", text_mode=True) |
| 634 | return Function(name=Sequence((Styled(name, _ROMAN_STYLE),))) |
| 635 | if command in {"frac", "dfrac", "tfrac", "cfrac", "ifrac"}: |
| 636 | if ( |
| 637 | command == "cfrac" |
| 638 | and self.position < len(self.source) |
| 639 | and self.source[self.position] == "[" |
| 640 | ): |
| 641 | self._parse_raw_optional_group("continued-fraction alignment") |
| 642 | numerator = self._parse_required_argument("fraction numerator") |
| 643 | denominator = self._parse_required_argument("fraction denominator") |
| 644 | return Fraction( |
| 645 | numerator=numerator, |
| 646 | denominator=denominator, |
| 647 | kind="skw" if command == "ifrac" else "bar", |
| 648 | ) |
| 649 | if command in {"binom", "dbinom", "tbinom"}: |
| 650 | numerator = self._parse_required_argument("binomial numerator") |
| 651 | denominator = self._parse_required_argument("binomial denominator") |
| 652 | fraction = Fraction(numerator, denominator, kind="noBar") |
| 653 | return Delimiter("(", ")", (Sequence((fraction,)),)) |
| 654 | if command == "genfrac": |
| 655 | left = self._delimiter_from_raw(self._parse_raw_required_group("left delimiter")) |
| 656 | right = self._delimiter_from_raw(self._parse_raw_required_group("right delimiter")) |
| 657 | thickness = self._parse_raw_required_group("fraction thickness").strip() |
| 658 | self._parse_raw_required_group("fraction style") |
| 659 | numerator = self._parse_required_argument("fraction numerator") |
| 660 | denominator = self._parse_required_argument("fraction denominator") |
| 661 | if not thickness: |
| 662 | kind = "bar" |
| 663 | elif thickness == "0": |
| 664 | kind = "noBar" |
| 665 | else: |
| 666 | thickness_match = _LENGTH_RE.fullmatch(thickness) |
| 667 | if thickness_match is None: |
| 668 | self._fail( |
| 669 | f"Invalid generalized-fraction thickness {thickness!r}" |
| 670 | ) |
| 671 | kind = ( |
| 672 | "noBar" |
| 673 | if float(thickness_match.group(1)) == 0.0 |
| 674 | else "bar" |
| 675 | ) |
| 676 | fraction = Fraction(numerator, denominator, kind=kind) |
| 677 | if left or right: |
| 678 | return Delimiter(left, right, (Sequence((fraction,)),)) |
| 679 | return fraction |
| 680 | if command == "sqrt": |
| 681 | degree = self._parse_optional_argument("radical degree") |
| 682 | body = self._parse_required_argument("radical body") |
| 683 | return Radical(body=body, degree=degree) |
| 684 | if command == "root": |
| 685 | degree = self._parse_nested_sequence(stop_commands=frozenset({"of"})) |
| 686 | if not self._at_control_word("of") or is_empty(degree): |
| 687 | self._fail("\\root requires a degree followed by \\of") |
| 688 | self._consume_control_word("of") |
| 689 | body = self._parse_required_argument("radical body") |
| 690 | return Radical(body=body, degree=degree) |
| 691 | if command in {"left", _BIG_LEFT_COMMAND}: |
| 692 | return self._parse_delimited_expression(command) |
| 693 | if command == _BIG_RIGHT_COMMAND: |
| 694 | right = self._parse_delimiter_token("explicit big right delimiter") |
| 695 | return Delimiter("", right, (Sequence(()),)) |
| 696 | if command == _BIG_MIDDLE_COMMAND: |
| 697 | separator = self._parse_delimiter_token("explicit big middle delimiter") |
| 698 | return Delimiter("", "", (Sequence(()), Sequence(())), separator) |
| 699 | if command == _BIG_SYMMETRIC_COMMAND: |
| 700 | return self._parse_big_symmetric_delimiter() |
| 701 | if command in {"right", "middle"}: |
| 702 | self._fail(f"Unexpected \\{command} without matching \\left", position=command_start) |
| 703 | if command == "begin": |
| 704 | return self._parse_environment() |
| 705 | if command == "end": |
| 706 | self._fail("Unexpected \\end without matching \\begin", position=command_start) |
| 707 | if command in _STYLE_WRAPPERS: |
| 708 | text_mode = command in { |
| 709 | "text", "textrm", "textnormal", "textbf", "textit", "emph", |
| 710 | "textsf", "texttt", "mbox", "hbox", |
| 711 | } |
| 712 | body = self._parse_required_argument(f"\\{command} body", text_mode=text_mode) |
| 713 | return Styled(body=body, style=_STYLE_WRAPPERS[command]) |
| 714 | if command in _DECLARATION_STYLES: |
| 715 | self.current_style = merge_run_styles( |
| 716 | self.current_style, |
| 717 | _DECLARATION_STYLES[command], |
| 718 | ) |
| 719 | return Sequence(()) |
| 720 | if command in ACCENT_COMMANDS: |
| 721 | body = self._parse_required_argument(f"\\{command} body") |
| 722 | return Accent(character=ACCENT_COMMANDS[command], body=body) |
| 723 | if command == "overline": |
| 724 | return Bar("top", self._parse_required_argument("overline body")) |
| 725 | if command == "underline": |
| 726 | return Bar("bot", self._parse_required_argument("underline body")) |
| 727 | if command in _OVER_UNDER_COMMANDS: |
| 728 | character, position, vertical = _OVER_UNDER_COMMANDS[command] |
| 729 | body = self._parse_required_argument(f"\\{command} body") |
| 730 | return GroupChar(character, position, vertical, body) |
| 731 | if command in _OVER_ARROW_COMMANDS: |
| 732 | body = self._parse_required_argument(f"\\{command} body") |
| 733 | return GroupChar(_OVER_ARROW_COMMANDS[command], "top", "bot", body) |
| 734 | if command in {"xrightarrow", "xleftarrow"}: |
| 735 | lower = self._parse_optional_argument("arrow lower label", allow_empty=True) |
| 736 | upper = self._parse_required_argument("arrow upper label", allow_empty=True) |
| 737 | arrow = GroupChar( |
| 738 | "→" if command == "xrightarrow" else "←", |
| 739 | "bot", |
| 740 | "top", |
| 741 | upper, |
| 742 | ) |
| 743 | return Limit(arrow, lower=lower) if lower is not None else arrow |
| 744 | if command in {"overset", "stackrel"}: |
| 745 | upper = self._parse_required_argument("upper limit") |
| 746 | base = self._single_node(self._parse_required_argument("limit base")) |
| 747 | return Limit(base=base, upper=upper) |
| 748 | if command == "underset": |
| 749 | lower = self._parse_required_argument("lower limit") |
| 750 | base = self._single_node(self._parse_required_argument("limit base")) |
| 751 | return Limit(base=base, lower=lower) |
| 752 | if command == "buildrel": |
| 753 | upper = self._parse_nested_sequence(stop_commands=frozenset({"over"})) |
| 754 | if not self._at_control_word("over"): |
| 755 | self._fail("\\buildrel requires \\over") |
| 756 | if is_empty(upper): |
| 757 | self._fail("\\buildrel requires an upper value") |
| 758 | self._consume_control_word("over") |
| 759 | base = self._single_node(self._parse_required_argument("buildrel base")) |
| 760 | return Limit(base=base, upper=upper) |
| 761 | if command == "substack": |
| 762 | raw = self._parse_raw_required_group("substack body") |
| 763 | return self._parse_synthetic_environment("aligned", raw) |
| 764 | if command == "bmod": |
| 765 | return Function(name=self._roman_name("mod")) |
| 766 | if command in {"pmod", "mod"}: |
| 767 | body = self._parse_required_argument(f"\\{command} body") |
| 768 | content = Sequence(( |
| 769 | Text("mod", _ROMAN_STYLE), |
| 770 | Text(" ", _SPACING_STYLE), |
| 771 | *body.children, |
| 772 | )) |
| 773 | if command == "pmod": |
| 774 | return Delimiter("(", ")", (content,)) |
| 775 | return content |
| 776 | if command in _STYLE_COLOR_COMMANDS: |
| 777 | color = self._parse_color() |
| 778 | body = self._parse_required_argument(f"\\{command} body") |
| 779 | return Styled(body, RunStyle(color=color)) |
| 780 | if command in {"boxed", "fbox", "framebox", "cancel", "bcancel", "xcancel"}: |
| 781 | body = self._parse_required_argument( |
| 782 | f"\\{command} body", |
| 783 | text_mode=command in {"fbox", "framebox"}, |
| 784 | ) |
| 785 | return BorderBox(body=body, kind=command) |
| 786 | if command in {"phantom", "hphantom", "vphantom"}: |
| 787 | return Phantom( |
| 788 | body=self._parse_required_argument(f"\\{command} body"), |
| 789 | kind=command, |
| 790 | ) |
| 791 | if command == "not": |
| 792 | target = self._parse_required_argument("negated relation") |
| 793 | node = self._single_node(target) |
| 794 | if isinstance(node, Text) and len(node.value) == 1: |
| 795 | negated = NEGATED_SYMBOLS.get(node.value) |
| 796 | if negated is not None: |
| 797 | return self._styled_text(negated, _ROMAN_STYLE) |
| 798 | return Accent("̸", target) |
| 799 | if command == "eqalign": |
| 800 | raw = self._parse_raw_required_group("eqalign body") |
| 801 | return self._parse_synthetic_environment("aligned", raw.replace("\\cr", "\\\\")) |
| 802 | if command == "ce": |
| 803 | raw = self._parse_raw_required_group("chemical expression") |
| 804 | return _ChemParser(raw, display=self.display).parse() |
| 805 | if command == "bra": |
| 806 | return Delimiter("⟨", "|", (self._parse_required_argument("bra body"),)) |
| 807 | if command == "ket": |
| 808 | return Delimiter("|", "⟩", (self._parse_required_argument("ket body"),)) |
| 809 | if command in SPACING_COMMANDS: |
| 810 | return self._styled_text(SPACING_COMMANDS[command], _SPACING_STYLE) |
| 811 | if command in {"mkern", "mskip"}: |
| 812 | return self._styled_text(self._parse_spacing_length(command), _SPACING_STYLE) |
| 813 | if command == "hspace": |
| 814 | return self._styled_text( |
| 815 | _space_from_length(self._parse_raw_required_group("horizontal space")), |
| 816 | _SPACING_STYLE, |
| 817 | ) |
| 818 | if command in NO_OUTPUT_COMMANDS: |
| 819 | return Sequence(()) |
| 820 | if command in DISCARDED_ARGUMENT_COMMANDS: |
| 821 | self._parse_required_argument(f"\\{command} body", allow_empty=True) |
| 822 | return Sequence(()) |
| 823 | if command == "mathrel": |
| 824 | return OperatorEmulator( |
| 825 | self._parse_required_argument("math relation body") |
| 826 | ) |
| 827 | if command == "mathop": |
| 828 | return Function( |
| 829 | name=self._parse_required_argument("math operator body"), |
| 830 | limit_style=True, |
| 831 | ) |
| 832 | |
| 833 | self._fail(f"Unsupported LaTeX command \\{command}", position=command_start) |
| 834 | |
| 835 | def _parse_group(self) -> Sequence: |
| 836 | self.position += 1 |
| 837 | saved_style = self.current_style |
| 838 | try: |
| 839 | return self._parse_nested_sequence(terminator="}") |
| 840 | finally: |
| 841 | self.current_style = saved_style |
| 842 | |
| 843 | def _parse_required_argument( |
| 844 | self, |
| 845 | description: str, |
| 846 | *, |
| 847 | allow_empty: bool = False, |
| 848 | text_mode: bool = False, |
| 849 | ) -> Sequence: |
| 850 | self._skip_whitespace() |
| 851 | saved_text_depth = self.text_mode_depth |
| 852 | if text_mode: |
| 853 | self.text_mode_depth += 1 |
| 854 | try: |
| 855 | if self.position >= len(self.source): |
| 856 | self._fail(f"{description.capitalize()} is missing") |
| 857 | if self.source[self.position] == "{": |
| 858 | result = self._parse_group() |
| 859 | else: |
| 860 | result = Sequence((self._parse_nested_bare_atom(),)) |
| 861 | finally: |
| 862 | self.text_mode_depth = saved_text_depth |
| 863 | if not allow_empty and is_empty(result): |
| 864 | self._fail(f"{description.capitalize()} cannot be empty") |
| 865 | return result |
| 866 | |
| 867 | def _parse_optional_argument( |
| 868 | self, |
| 869 | description: str, |
| 870 | *, |
| 871 | allow_empty: bool = False, |
| 872 | ) -> Sequence | None: |
| 873 | self._skip_whitespace() |
| 874 | if self.position >= len(self.source) or self.source[self.position] != "[": |
| 875 | return None |
| 876 | self.position += 1 |
| 877 | result = self._parse_nested_sequence(terminator="]") |
| 878 | if not allow_empty and is_empty(result): |
| 879 | self._fail(f"{description.capitalize()} cannot be empty") |
| 880 | return result |
| 881 | |
| 882 | def _parse_raw_required_group(self, description: str) -> str: |
| 883 | try: |
| 884 | raw, self.position = _read_raw_group(self.source, self.position) |
| 885 | except FormulaCompileError as exc: |
| 886 | self._fail(f"{description.capitalize()} must use a braced group") |
| 887 | raise AssertionError from exc |
| 888 | return raw |
| 889 | |
| 890 | def _parse_raw_optional_group(self, description: str) -> str | None: |
| 891 | self._skip_whitespace() |
| 892 | if self.position >= len(self.source) or self.source[self.position] != "[": |
| 893 | return None |
| 894 | closing = self.source.find("]", self.position + 1) |
| 895 | if closing < 0: |
| 896 | self._fail(f"Unclosed {description}") |
| 897 | raw = self.source[self.position + 1:closing] |
| 898 | self.position = closing + 1 |
| 899 | self._skip_whitespace() |
| 900 | return raw |
| 901 | |
| 902 | def _parse_nested_sequence(self, **kwargs: object) -> Sequence: |
| 903 | self.depth += 1 |
| 904 | if self.depth > _MAX_PARSE_DEPTH: |
| 905 | self._fail(f"Formula nesting exceeds {_MAX_PARSE_DEPTH} levels") |
| 906 | try: |
| 907 | return self._parse_sequence(**kwargs) |
| 908 | finally: |
| 909 | self.depth -= 1 |
| 910 | |
| 911 | def _parse_nested_atom(self) -> Node: |
| 912 | self.depth += 1 |
| 913 | if self.depth > _MAX_PARSE_DEPTH: |
| 914 | self._fail(f"Formula nesting exceeds {_MAX_PARSE_DEPTH} levels") |
| 915 | try: |
| 916 | return self._parse_complete_atom() |
| 917 | finally: |
| 918 | self.depth -= 1 |
| 919 | |
| 920 | def _parse_nested_bare_atom(self) -> Node: |
| 921 | self.depth += 1 |
| 922 | if self.depth > _MAX_PARSE_DEPTH: |
| 923 | self._fail(f"Formula nesting exceeds {_MAX_PARSE_DEPTH} levels") |
| 924 | try: |
| 925 | return self._parse_atom() |
| 926 | finally: |
| 927 | self.depth -= 1 |
| 928 | |
| 929 | def _parse_complete_atom(self) -> Node: |
| 930 | atom = self._parse_atom() |
| 931 | if isinstance(atom, (Nary, Function)): |
| 932 | atom = self._parse_limit_modifier(atom) |
| 933 | atom = self._parse_scripts(atom) |
| 934 | if isinstance(atom, (Nary, Function)): |
| 935 | atom = self._parse_limit_modifier(atom) |
| 936 | atom = self._parse_owned_body(atom) |
| 937 | return atom |
| 938 | |
| 939 | def _parse_scripts(self, base: Node) -> Node: |
| 940 | subscript: Sequence | None = None |
| 941 | superscript: Sequence | None = None |
| 942 | while True: |
| 943 | saved_position = self.position |
| 944 | self._skip_whitespace() |
| 945 | if self.position >= len(self.source) or self.source[self.position] not in "^_": |
| 946 | self.position = saved_position |
| 947 | break |
| 948 | marker = self.source[self.position] |
| 949 | self.position += 1 |
| 950 | argument = self._parse_required_argument(f"script marker {marker!r}") |
| 951 | if marker == "_": |
| 952 | if subscript is not None: |
| 953 | self._fail("Duplicate subscript for one base") |
| 954 | subscript = argument |
| 955 | else: |
| 956 | if superscript is not None: |
| 957 | self._fail("Duplicate superscript for one base") |
| 958 | superscript = argument |
| 959 | if subscript is None and superscript is None: |
| 960 | return base |
| 961 | if isinstance(base, Nary): |
| 962 | return Nary( |
| 963 | base.symbol, |
| 964 | base.category, |
| 965 | subscript, |
| 966 | superscript, |
| 967 | base.body, |
| 968 | base.limit_modifier, |
| 969 | ) |
| 970 | if isinstance(base, Function): |
| 971 | return Function( |
| 972 | base.name, |
| 973 | base.body, |
| 974 | subscript, |
| 975 | superscript, |
| 976 | base.limit_style, |
| 977 | base.limit_modifier, |
| 978 | ) |
| 979 | if isinstance(base, GroupChar): |
| 980 | return Limit(base, lower=subscript, upper=superscript) |
| 981 | if isinstance(base, Limit): |
| 982 | return Limit( |
| 983 | base.base, |
| 984 | lower=subscript or base.lower, |
| 985 | upper=superscript or base.upper, |
| 986 | ) |
| 987 | return Script(base, subscript=subscript, superscript=superscript) |
| 988 | |
| 989 | def _parse_prescript(self) -> Prescript: |
| 990 | subscript: Sequence | None = None |
| 991 | superscript: Sequence | None = None |
| 992 | while self.position < len(self.source) and self.source[self.position] in "^_": |
| 993 | marker = self.source[self.position] |
| 994 | self.position += 1 |
| 995 | argument = self._parse_required_argument(f"pre-script marker {marker!r}") |
| 996 | if marker == "_": |
| 997 | if subscript is not None: |
| 998 | self._fail("Duplicate pre-subscript") |
| 999 | subscript = argument |
| 1000 | else: |
| 1001 | if superscript is not None: |
| 1002 | self._fail("Duplicate pre-superscript") |
| 1003 | superscript = argument |
| 1004 | self._skip_whitespace() |
| 1005 | if self.position >= len(self.source): |
| 1006 | self._fail("Pre-script has no base") |
| 1007 | base = self._parse_nested_atom() |
| 1008 | return Prescript(base, subscript=subscript, superscript=superscript) |
| 1009 | |
| 1010 | def _parse_limit_modifier(self, node: Nary | Function) -> Nary | Function: |
| 1011 | saved = self.position |
| 1012 | self._skip_whitespace() |
| 1013 | command: str | None = None |
| 1014 | if self._at_control_word("limits"): |
| 1015 | command = "limits" |
| 1016 | elif self._at_control_word("nolimits"): |
| 1017 | command = "nolimits" |
| 1018 | if command is None: |
| 1019 | self.position = saved |
| 1020 | return node |
| 1021 | if node.limit_modifier is not None: |
| 1022 | self._fail("Operator has more than one limit modifier") |
| 1023 | self._consume_control_word(command) |
| 1024 | if isinstance(node, Nary): |
| 1025 | return Nary( |
| 1026 | node.symbol, |
| 1027 | node.category, |
| 1028 | node.subscript, |
| 1029 | node.superscript, |
| 1030 | node.body, |
| 1031 | command, |
| 1032 | ) |
| 1033 | return Function( |
| 1034 | node.name, |
| 1035 | node.body, |
| 1036 | node.subscript, |
| 1037 | node.superscript, |
| 1038 | node.limit_style, |
| 1039 | command, |
| 1040 | ) |
| 1041 | |
| 1042 | def _parse_owned_body(self, node: Nary | Function) -> Nary | Function: |
| 1043 | if node.body is not None: |
| 1044 | return node |
| 1045 | saved = self.position |
| 1046 | self._skip_whitespace() |
| 1047 | leading_spacing: list[Node] = [] |
| 1048 | while self._transparent_prefix_follows(): |
| 1049 | append_child(leading_spacing, self._parse_nested_atom()) |
| 1050 | self._skip_whitespace() |
| 1051 | if self.position < len(self.source) and self.source[self.position] in "+-": |
| 1052 | append_child(leading_spacing, self._parse_nested_atom()) |
| 1053 | self._skip_whitespace() |
| 1054 | while self._transparent_prefix_follows(): |
| 1055 | append_child(leading_spacing, self._parse_nested_atom()) |
| 1056 | self._skip_whitespace() |
| 1057 | if not self._owned_body_follows(): |
| 1058 | self.position = saved |
| 1059 | return node |
| 1060 | if self.source[self.position] == "{": |
| 1061 | body = self._parse_group() |
| 1062 | else: |
| 1063 | body = Sequence((self._parse_nested_atom(),)) |
| 1064 | if leading_spacing: |
| 1065 | body = Sequence((*leading_spacing, *body.children)) |
| 1066 | if isinstance(node, Nary): |
| 1067 | children = list(body.children) |
| 1068 | while True: |
| 1069 | saved_tail = self.position |
| 1070 | self._skip_whitespace() |
| 1071 | tail_prefix: list[Node] = [] |
| 1072 | while self._transparent_prefix_follows(): |
| 1073 | append_child(tail_prefix, self._parse_nested_atom()) |
| 1074 | self._skip_whitespace() |
| 1075 | if not self._owned_body_follows(): |
| 1076 | self.position = saved_tail |
| 1077 | break |
| 1078 | for prefix_node in tail_prefix: |
| 1079 | append_child(children, prefix_node) |
| 1080 | append_child(children, self._parse_nested_atom()) |
| 1081 | body = Sequence(tuple(children)) |
| 1082 | elif isinstance(node, Function): |
| 1083 | children = list(body.children) |
| 1084 | while self._call_delimiter_follows(): |
| 1085 | append_child(children, self._parse_nested_atom()) |
| 1086 | body = Sequence(tuple(children)) |
| 1087 | if isinstance(node, Nary): |
| 1088 | return Nary( |
| 1089 | node.symbol, |
| 1090 | node.category, |
| 1091 | node.subscript, |
| 1092 | node.superscript, |
| 1093 | body, |
| 1094 | node.limit_modifier, |
| 1095 | ) |
| 1096 | return Function( |
| 1097 | node.name, |
| 1098 | body, |
| 1099 | node.subscript, |
| 1100 | node.superscript, |
| 1101 | node.limit_style, |
| 1102 | node.limit_modifier, |
| 1103 | ) |
| 1104 | |
| 1105 | def _transparent_prefix_follows(self) -> bool: |
| 1106 | if self.position >= len(self.source): |
| 1107 | return False |
| 1108 | if self.source[self.position] == "~": |
| 1109 | return True |
| 1110 | if self.source[self.position] != "\\" or self.position + 1 >= len(self.source): |
| 1111 | return False |
| 1112 | following = self.source[self.position + 1] |
| 1113 | if not _is_command_letter(following): |
| 1114 | return following in SPACING_COMMANDS |
| 1115 | command, _ = _read_control_word(self.source, self.position) |
| 1116 | return ( |
| 1117 | command in SPACING_COMMANDS |
| 1118 | or command in NO_OUTPUT_COMMANDS |
| 1119 | or command in {"mkern", "mskip", "hspace"} |
| 1120 | ) |
| 1121 | |
| 1122 | def _call_delimiter_follows(self) -> bool: |
| 1123 | self._skip_whitespace() |
| 1124 | if self.position >= len(self.source): |
| 1125 | return False |
| 1126 | if self.source[self.position] in "([|": |
| 1127 | return True |
| 1128 | if self.source.startswith((r"\|", r"\{"), self.position): |
| 1129 | return True |
| 1130 | if self.source[self.position] != "\\": |
| 1131 | return False |
| 1132 | if self.position + 1 >= len(self.source) or not _is_command_letter( |
| 1133 | self.source[self.position + 1] |
| 1134 | ): |
| 1135 | return False |
| 1136 | command, _ = _read_control_word(self.source, self.position) |
| 1137 | return command in BARE_DELIMITER_COMMAND_PAIRS |
| 1138 | |
| 1139 | def _owned_body_follows(self) -> bool: |
| 1140 | if self.position >= len(self.source) or self._at_environment_boundary(): |
| 1141 | return False |
| 1142 | if any( |
| 1143 | self._at_control_word(command) |
| 1144 | for command in {"right", "middle", "end"} |
| 1145 | ): |
| 1146 | return False |
| 1147 | char = self.source[self.position] |
| 1148 | if char in "}])&^_+-=<>/,;:!?": |
| 1149 | return False |
| 1150 | if char != "\\": |
| 1151 | return True |
| 1152 | if ( |
| 1153 | self.position + 1 < len(self.source) |
| 1154 | and not _is_command_letter(self.source[self.position + 1]) |
| 1155 | ): |
| 1156 | return self.source[self.position + 1] not in {"\\", ",", ";", ":", "!", " "} |
| 1157 | command, _ = _read_control_word(self.source, self.position) |
| 1158 | return command not in OPERATOR_BOUNDARY_COMMANDS |
| 1159 | |
| 1160 | def _parse_delimited_expression(self, command: str = "left") -> Delimiter: |
| 1161 | left = self._parse_delimiter_token(f"\\{command}") |
| 1162 | segments: list[Sequence] = [] |
| 1163 | separator = "" |
| 1164 | stop_commands = frozenset({ |
| 1165 | *_MIDDLE_DELIMITER_COMMANDS, |
| 1166 | *_RIGHT_DELIMITER_COMMANDS, |
| 1167 | }) |
| 1168 | while True: |
| 1169 | segments.append( |
| 1170 | self._parse_nested_sequence(stop_commands=stop_commands) |
| 1171 | ) |
| 1172 | middle_command = next( |
| 1173 | ( |
| 1174 | candidate |
| 1175 | for candidate in _MIDDLE_DELIMITER_COMMANDS |
| 1176 | if self._at_control_word(candidate) |
| 1177 | ), |
| 1178 | None, |
| 1179 | ) |
| 1180 | if middle_command is not None: |
| 1181 | self._consume_control_word(middle_command) |
| 1182 | current = self._parse_delimiter_token(f"\\{middle_command}") |
| 1183 | if separator and separator != current: |
| 1184 | self._fail("One delimiter expression cannot mix middle characters") |
| 1185 | separator = current |
| 1186 | continue |
| 1187 | right = "" |
| 1188 | right_command = next( |
| 1189 | ( |
| 1190 | candidate |
| 1191 | for candidate in _RIGHT_DELIMITER_COMMANDS |
| 1192 | if self._at_control_word(candidate) |
| 1193 | ), |
| 1194 | None, |
| 1195 | ) |
| 1196 | if right_command is not None: |
| 1197 | self._consume_control_word(right_command) |
| 1198 | right = self._parse_delimiter_token(f"\\{right_command}") |
| 1199 | return Delimiter(left, right, tuple(segments), separator) |
| 1200 | |
| 1201 | def _parse_big_symmetric_delimiter(self) -> Delimiter: |
| 1202 | delimiter = self._parse_delimiter_token("explicit big symmetric delimiter") |
| 1203 | body_start = self.position |
| 1204 | closing = self._find_matching_big_symmetric(delimiter, body_start) |
| 1205 | if closing is None: |
| 1206 | return Delimiter("", "", (Sequence(()), Sequence(())), delimiter) |
| 1207 | closing_start, after_closing = closing |
| 1208 | body = self._parse_fragment(self.source[body_start:closing_start]) |
| 1209 | self.position = after_closing |
| 1210 | return Delimiter(delimiter, delimiter, (body,)) |
| 1211 | |
| 1212 | def _find_matching_big_symmetric( |
| 1213 | self, |
| 1214 | delimiter: str, |
| 1215 | start: int, |
| 1216 | ) -> tuple[int, int] | None: |
| 1217 | group_depth = 0 |
| 1218 | cursor = start |
| 1219 | while cursor < len(self.source): |
| 1220 | char = self.source[cursor] |
| 1221 | if char == "{": |
| 1222 | group_depth += 1 |
| 1223 | cursor += 1 |
| 1224 | continue |
| 1225 | if char == "}": |
| 1226 | group_depth = max(0, group_depth - 1) |
| 1227 | cursor += 1 |
| 1228 | continue |
| 1229 | if char != "\\" or cursor + 1 >= len(self.source): |
| 1230 | cursor += 1 |
| 1231 | continue |
| 1232 | if not _is_command_letter(self.source[cursor + 1]): |
| 1233 | cursor += 2 |
| 1234 | continue |
| 1235 | command, after_command = _read_control_word(self.source, cursor) |
| 1236 | if group_depth != 0 or command != _BIG_SYMMETRIC_COMMAND: |
| 1237 | cursor = after_command |
| 1238 | continue |
| 1239 | saved_position = self.position |
| 1240 | try: |
| 1241 | self.position = _skip_whitespace(self.source, after_command) |
| 1242 | candidate = self._parse_delimiter_token( |
| 1243 | "explicit big symmetric delimiter" |
| 1244 | ) |
| 1245 | after_delimiter = self.position |
| 1246 | finally: |
| 1247 | self.position = saved_position |
| 1248 | if candidate == delimiter: |
| 1249 | return cursor, after_delimiter |
| 1250 | cursor = after_delimiter |
| 1251 | return None |
| 1252 | |
| 1253 | def _parse_delimiter_token(self, owner: str) -> str: |
| 1254 | self._skip_whitespace() |
| 1255 | if self.position >= len(self.source): |
| 1256 | self._fail(f"{owner} requires a delimiter") |
| 1257 | char = self.source[self.position] |
| 1258 | if char != "\\": |
| 1259 | self.position += 1 |
| 1260 | if char in "()[]|.⟦⟧": |
| 1261 | return "" if char == "." else char |
| 1262 | self._fail(f"Unsupported delimiter {char!r} after {owner}") |
| 1263 | command_start = self.position |
| 1264 | self.position += 1 |
| 1265 | if self.position >= len(self.source): |
| 1266 | self._fail(f"{owner} requires a delimiter", position=command_start) |
| 1267 | if not _is_command_letter(self.source[self.position]): |
| 1268 | delimiter = self.source[self.position] |
| 1269 | self.position += 1 |
| 1270 | if delimiter in "{}|": |
| 1271 | return "‖" if delimiter == "|" else delimiter |
| 1272 | self._fail(f"Unsupported delimiter command \\{delimiter}", position=command_start) |
| 1273 | command = self._read_control_word_body() |
| 1274 | self._skip_whitespace() |
| 1275 | if command not in DELIMITER_COMMANDS: |
| 1276 | self._fail(f"Unsupported delimiter command \\{command}", position=command_start) |
| 1277 | return DELIMITER_COMMANDS[command] |
| 1278 | |
| 1279 | def _parse_or_literal_character_delimiter(self, opener: str) -> Node: |
| 1280 | closer = {"(": ")", "[": "]", "|": "|"}[opener] |
| 1281 | start = self.position |
| 1282 | if opener == closer: |
| 1283 | closing = self._find_symmetric_character(start, opener) |
| 1284 | else: |
| 1285 | closing = self._find_matching_character(start, opener, closer) |
| 1286 | if closing is None: |
| 1287 | self.position += 1 |
| 1288 | return self._styled_text(opener, _ROMAN_STYLE) |
| 1289 | body_source = self.source[start + 1:closing] |
| 1290 | body = self._parse_fragment(body_source) |
| 1291 | self.position = closing + 1 |
| 1292 | return Delimiter(opener, closer, (body,)) |
| 1293 | |
| 1294 | def _find_symmetric_character(self, start: int, delimiter: str) -> int | None: |
| 1295 | group_depth = 0 |
| 1296 | cursor = start + 1 |
| 1297 | while cursor < len(self.source): |
| 1298 | char = self.source[cursor] |
| 1299 | if char == "\\": |
| 1300 | cursor += 2 |
| 1301 | continue |
| 1302 | if char == "{": |
| 1303 | group_depth += 1 |
| 1304 | elif char == "}" and group_depth: |
| 1305 | group_depth -= 1 |
| 1306 | elif char == delimiter and group_depth == 0: |
| 1307 | return cursor |
| 1308 | cursor += 1 |
| 1309 | return None |
| 1310 | |
| 1311 | def _try_escaped_brace_delimiter(self) -> Node | None: |
| 1312 | closing = self._find_matching_control_symbol("{", "}", self.position) |
| 1313 | if closing is None: |
| 1314 | return None |
| 1315 | body = self._parse_fragment(self.source[self.position:closing]) |
| 1316 | self.position = closing + 2 |
| 1317 | return Delimiter("{", "}", (body,)) |
| 1318 | |
| 1319 | def _try_command_delimiter(self, command: str, command_start: int) -> Node | None: |
| 1320 | pair = BARE_DELIMITER_COMMAND_PAIRS.get(command) |
| 1321 | if pair is None: |
| 1322 | return None |
| 1323 | closing_command, left, right = pair |
| 1324 | closing = self._find_matching_control_word(command, closing_command, self.position) |
| 1325 | if closing is None: |
| 1326 | return None |
| 1327 | body = self._parse_fragment(self.source[self.position:closing]) |
| 1328 | _, after = _read_control_word(self.source, closing) |
| 1329 | self.position = _skip_whitespace(self.source, after) |
| 1330 | return Delimiter(left, right, (body,)) |
| 1331 | |
| 1332 | def _try_symmetric_command_delimiter(self, command_start: int) -> Node | None: |
| 1333 | closing = self.source.find("\\|", self.position) |
| 1334 | if closing < 0: |
| 1335 | return None |
| 1336 | body = self._parse_fragment(self.source[self.position:closing]) |
| 1337 | self.position = closing + 2 |
| 1338 | return Delimiter("‖", "‖", (body,)) |
| 1339 | |
| 1340 | def _try_symmetric_named_delimiter(self, command: str) -> Node | None: |
| 1341 | closing = self._find_symmetric_control_word(command, self.position) |
| 1342 | if closing is None: |
| 1343 | return None |
| 1344 | body = self._parse_fragment(self.source[self.position:closing]) |
| 1345 | _, after = _read_control_word(self.source, closing) |
| 1346 | self.position = _skip_whitespace(self.source, after) |
| 1347 | delimiter = "‖" if command == "Vert" else "|" |
| 1348 | return Delimiter(delimiter, delimiter, (body,)) |
| 1349 | |
| 1350 | def _find_matching_character(self, start: int, opener: str, closer: str) -> int | None: |
| 1351 | expected_closers = [closer] |
| 1352 | group_depth = 0 |
| 1353 | cursor = start + 1 |
| 1354 | explicit_delimiter_commands = { |
| 1355 | "left", |
| 1356 | "right", |
| 1357 | "middle", |
| 1358 | _BIG_LEFT_COMMAND, |
| 1359 | _BIG_RIGHT_COMMAND, |
| 1360 | _BIG_MIDDLE_COMMAND, |
| 1361 | _BIG_SYMMETRIC_COMMAND, |
| 1362 | } |
| 1363 | while cursor < len(self.source): |
| 1364 | char = self.source[cursor] |
| 1365 | if char == "\\": |
| 1366 | if cursor + 1 >= len(self.source): |
| 1367 | return None |
| 1368 | if not _is_command_letter(self.source[cursor + 1]): |
| 1369 | cursor += 2 |
| 1370 | continue |
| 1371 | command, cursor = _read_control_word(self.source, cursor) |
| 1372 | if group_depth == 0 and command in explicit_delimiter_commands: |
| 1373 | cursor = self._skip_scanned_delimiter_token(cursor) |
| 1374 | continue |
| 1375 | if char == "{": |
| 1376 | group_depth += 1 |
| 1377 | cursor += 1 |
| 1378 | continue |
| 1379 | if char == "}": |
| 1380 | if group_depth == 0: |
| 1381 | return None |
| 1382 | group_depth -= 1 |
| 1383 | cursor += 1 |
| 1384 | continue |
| 1385 | if group_depth == 0: |
| 1386 | if char in "([": |
| 1387 | expected_closers.append(")" if char == "(" else "]") |
| 1388 | elif char in ")]": |
| 1389 | if char != expected_closers[-1]: |
| 1390 | return None |
| 1391 | expected_closers.pop() |
| 1392 | if not expected_closers: |
| 1393 | return cursor |
| 1394 | cursor += 1 |
| 1395 | return None |
| 1396 | |
| 1397 | def _skip_scanned_delimiter_token(self, position: int) -> int: |
| 1398 | position = _skip_whitespace(self.source, position) |
| 1399 | if position >= len(self.source): |
| 1400 | return position |
| 1401 | if self.source[position] != "\\": |
| 1402 | return position + 1 |
| 1403 | if position + 1 >= len(self.source): |
| 1404 | return len(self.source) |
| 1405 | if not _is_command_letter(self.source[position + 1]): |
| 1406 | return position + 2 |
| 1407 | _, position = _read_control_word(self.source, position) |
| 1408 | return position |
| 1409 | |
| 1410 | def _find_matching_control_symbol( |
| 1411 | self, |
| 1412 | opener: str, |
| 1413 | closer: str, |
| 1414 | start: int, |
| 1415 | ) -> int | None: |
| 1416 | depth = 1 |
| 1417 | cursor = start |
| 1418 | while cursor + 1 < len(self.source): |
| 1419 | if self.source[cursor] != "\\": |
| 1420 | cursor += 1 |
| 1421 | continue |
| 1422 | symbol = self.source[cursor + 1] |
| 1423 | if symbol == opener: |
| 1424 | depth += 1 |
| 1425 | elif symbol == closer: |
| 1426 | depth -= 1 |
| 1427 | if depth == 0: |
| 1428 | return cursor |
| 1429 | cursor += 2 |
| 1430 | return None |
| 1431 | |
| 1432 | def _find_matching_control_word( |
| 1433 | self, |
| 1434 | opener: str, |
| 1435 | closer: str, |
| 1436 | start: int, |
| 1437 | ) -> int | None: |
| 1438 | depth = 1 |
| 1439 | cursor = start |
| 1440 | while cursor < len(self.source): |
| 1441 | if self.source[cursor] != "\\" or cursor + 1 >= len(self.source): |
| 1442 | cursor += 1 |
| 1443 | continue |
| 1444 | if not _is_command_letter(self.source[cursor + 1]): |
| 1445 | cursor += 2 |
| 1446 | continue |
| 1447 | command, end = _read_control_word(self.source, cursor) |
| 1448 | if command == opener: |
| 1449 | depth += 1 |
| 1450 | elif command == closer: |
| 1451 | depth -= 1 |
| 1452 | if depth == 0: |
| 1453 | return cursor |
| 1454 | cursor = end |
| 1455 | return None |
| 1456 | |
| 1457 | def _find_symmetric_control_word( |
| 1458 | self, |
| 1459 | command: str, |
| 1460 | start: int, |
| 1461 | ) -> int | None: |
| 1462 | group_depth = 0 |
| 1463 | cursor = start |
| 1464 | while cursor < len(self.source): |
| 1465 | char = self.source[cursor] |
| 1466 | if char == "{": |
| 1467 | group_depth += 1 |
| 1468 | cursor += 1 |
| 1469 | continue |
| 1470 | if char == "}": |
| 1471 | group_depth = max(0, group_depth - 1) |
| 1472 | cursor += 1 |
| 1473 | continue |
| 1474 | if char != "\\" or cursor + 1 >= len(self.source): |
| 1475 | cursor += 1 |
| 1476 | continue |
| 1477 | if not _is_command_letter(self.source[cursor + 1]): |
| 1478 | cursor += 2 |
| 1479 | continue |
| 1480 | current, end = _read_control_word(self.source, cursor) |
| 1481 | if group_depth == 0 and current == command: |
| 1482 | return cursor |
| 1483 | cursor = end |
| 1484 | return None |
| 1485 | |
| 1486 | def _parse_environment(self) -> Node: |
| 1487 | environment = self._parse_environment_name("\\begin") |
| 1488 | if ( |
| 1489 | environment not in MATRIX_ENVIRONMENTS |
| 1490 | and environment not in EQUATION_ARRAY_ENVIRONMENTS |
| 1491 | ): |
| 1492 | self._fail(f"Unsupported formula environment {environment!r}") |
| 1493 | |
| 1494 | if environment == "CD": |
| 1495 | return self._parse_cd_environment() |
| 1496 | |
| 1497 | column_alignments: tuple[str, ...] = () |
| 1498 | if environment in {"array", "subarray"}: |
| 1499 | raw = self._parse_raw_required_group(f"{environment} column specification") |
| 1500 | filtered = tuple(char for char in raw if char in "lcr") |
| 1501 | if not filtered: |
| 1502 | self._fail(f"Environment {environment!r} requires l/c/r columns") |
| 1503 | column_alignments = tuple("center" for _ in filtered) |
| 1504 | elif environment in {"alignat", "alignat*", "alignedat"}: |
| 1505 | raw = self._parse_raw_required_group(f"{environment} column count").strip() |
| 1506 | if not raw.isdigit() or int(raw) <= 0: |
| 1507 | self._fail(f"Environment {environment!r} requires a positive column count") |
| 1508 | |
| 1509 | self.environment_stack.append(environment) |
| 1510 | try: |
| 1511 | rows = self._parse_environment_rows(environment) |
| 1512 | finally: |
| 1513 | self.environment_stack.pop() |
| 1514 | |
| 1515 | if environment in MATRIX_ENVIRONMENTS: |
| 1516 | if not column_alignments and rows: |
| 1517 | column_alignments = tuple("center" for _ in rows[0]) |
| 1518 | matrix = Matrix(environment, rows, column_alignments) |
| 1519 | delimiters = MATRIX_ENVIRONMENTS[environment] |
| 1520 | if delimiters is not None: |
| 1521 | return Delimiter(delimiters[0], delimiters[1], (Sequence((matrix,)),)) |
| 1522 | return matrix |
| 1523 | |
| 1524 | eq_rows: list[Sequence] = [] |
| 1525 | for row in rows: |
| 1526 | children: list[Node] = [] |
| 1527 | for index, cell in enumerate(row): |
| 1528 | if index: |
| 1529 | children.append(AlignmentPoint()) |
| 1530 | children.extend(cell.children) |
| 1531 | eq_rows.append(Sequence(tuple(children))) |
| 1532 | equation_array = EquationArray(tuple(eq_rows)) |
| 1533 | if environment == "cases": |
| 1534 | return Delimiter("{", "", (Sequence((equation_array,)),)) |
| 1535 | if environment == "rcases": |
| 1536 | return Delimiter("", "}", (Sequence((equation_array,)),)) |
| 1537 | return equation_array |
| 1538 | |
| 1539 | def _parse_cd_environment(self) -> Matrix: |
| 1540 | ending = r"\end{CD}" |
| 1541 | closing = self.source.find(ending, self.position) |
| 1542 | if closing < 0: |
| 1543 | self._fail("Unclosed formula environment 'CD'") |
| 1544 | raw = self.source[self.position:closing] |
| 1545 | self.position = closing + len(ending) |
| 1546 | raw_rows = re.split(r"\\\\|\\cr(?![A-Za-z])", raw) |
| 1547 | if raw_rows and not raw_rows[-1].strip(): |
| 1548 | raw_rows.pop() |
| 1549 | rows: list[tuple[Sequence, ...]] = [] |
| 1550 | for raw_row in raw_rows: |
| 1551 | row = raw_row.strip() |
| 1552 | if not row: |
| 1553 | self._fail("Environment 'CD' cannot contain an empty row") |
| 1554 | horizontal_parts = re.split(r"@(>>>|<<<)", row) |
| 1555 | if len(horizontal_parts) > 1: |
| 1556 | cells: list[Sequence] = [] |
| 1557 | for index, part in enumerate(horizontal_parts): |
| 1558 | if index % 2: |
| 1559 | cells.append(Sequence((Text( |
| 1560 | "→" if part == ">>>" else "←", |
| 1561 | _ROMAN_STYLE, |
| 1562 | ),))) |
| 1563 | else: |
| 1564 | if "@" in part: |
| 1565 | self._fail( |
| 1566 | "Environment 'CD' supports only @>>>, @<<<, @VVV, and @AAA" |
| 1567 | ) |
| 1568 | cells.append(self._parse_fragment(part.strip())) |
| 1569 | rows.append(tuple(cells)) |
| 1570 | continue |
| 1571 | vertical_tokens = re.findall(r"@(VVV|AAA)", row) |
| 1572 | vertical_remainder = re.sub(r"@(VVV|AAA)|[&\s]", "", row) |
| 1573 | if vertical_tokens and not vertical_remainder: |
| 1574 | cells: list[Sequence] = [] |
| 1575 | for index, token in enumerate(vertical_tokens): |
| 1576 | if index: |
| 1577 | cells.append(Sequence(())) |
| 1578 | cells.append(Sequence((Text( |
| 1579 | "↓" if token == "VVV" else "↑", |
| 1580 | _ROMAN_STYLE, |
| 1581 | ),))) |
| 1582 | rows.append(tuple(cells)) |
| 1583 | continue |
| 1584 | if "@" in row: |
| 1585 | self._fail("Environment 'CD' supports only @>>>, @<<<, @VVV, and @AAA") |
| 1586 | rows.append(tuple(self._parse_fragment(cell.strip()) for cell in row.split("&"))) |
| 1587 | if not rows: |
| 1588 | self._fail("Environment 'CD' cannot be empty") |
| 1589 | column_count = max(len(row) for row in rows) |
| 1590 | padded_rows = tuple( |
| 1591 | (*row, *(Sequence(()) for _ in range(column_count - len(row)))) |
| 1592 | for row in rows |
| 1593 | ) |
| 1594 | return Matrix( |
| 1595 | "CD", |
| 1596 | padded_rows, |
| 1597 | tuple("center" for _ in range(column_count)), |
| 1598 | ) |
| 1599 | |
| 1600 | def _parse_environment_rows( |
| 1601 | self, |
| 1602 | environment: str, |
| 1603 | ) -> tuple[tuple[Sequence, ...], ...]: |
| 1604 | rows: list[tuple[Sequence, ...]] = [] |
| 1605 | row: list[Sequence] = [] |
| 1606 | while True: |
| 1607 | cell = self._parse_nested_sequence(stop_at_environment_boundary=True) |
| 1608 | row.append(cell) |
| 1609 | if self.position < len(self.source) and self.source[self.position] == "&": |
| 1610 | self.position += 1 |
| 1611 | continue |
| 1612 | if self.source.startswith("\\\\", self.position): |
| 1613 | self.position += 2 |
| 1614 | rows.append(tuple(row)) |
| 1615 | row = [] |
| 1616 | self._skip_whitespace() |
| 1617 | if self._at_control_word("end"): |
| 1618 | self._consume_environment_end(environment) |
| 1619 | break |
| 1620 | continue |
| 1621 | if self._at_control_word("cr"): |
| 1622 | self._consume_control_word("cr") |
| 1623 | rows.append(tuple(row)) |
| 1624 | row = [] |
| 1625 | if self._at_control_word("end"): |
| 1626 | self._consume_environment_end(environment) |
| 1627 | break |
| 1628 | continue |
| 1629 | if self._at_control_word("end"): |
| 1630 | rows.append(tuple(row)) |
| 1631 | self._consume_environment_end(environment) |
| 1632 | break |
| 1633 | self._fail(f"Malformed environment {environment!r}") |
| 1634 | if not rows or not rows[0]: |
| 1635 | self._fail(f"Environment {environment!r} cannot be empty") |
| 1636 | if environment in MATRIX_ENVIRONMENTS: |
| 1637 | column_count = len(rows[0]) |
| 1638 | if any(len(current) != column_count for current in rows): |
| 1639 | self._fail(f"Environment {environment!r} has inconsistent column counts") |
| 1640 | return tuple(rows) |
| 1641 | |
| 1642 | def _parse_synthetic_environment(self, environment: str, raw: str) -> Node: |
| 1643 | parser = _LatexParser( |
| 1644 | f"\\begin{{{environment}}}{raw}\\end{{{environment}}}", |
| 1645 | display=self.display, |
| 1646 | inherited_style=self.current_style, |
| 1647 | ) |
| 1648 | result = parser.parse() |
| 1649 | return self._single_node(result) |
| 1650 | |
| 1651 | def _consume_environment_end(self, expected: str) -> None: |
| 1652 | self._consume_control_word("end") |
| 1653 | actual = self._parse_environment_name("\\end") |
| 1654 | if actual != expected: |
| 1655 | self._fail( |
| 1656 | f"Mismatched environment ending: expected {expected!r}, got {actual!r}" |
| 1657 | ) |
| 1658 | |
| 1659 | def _parse_environment_name(self, owner: str) -> str: |
| 1660 | raw = self._parse_raw_required_group(f"{owner} environment name") |
| 1661 | if _ENVIRONMENT_NAME_RE.fullmatch(raw) is None: |
| 1662 | self._fail(f"Invalid environment name {raw!r}") |
| 1663 | return raw |
| 1664 | |
| 1665 | def _at_environment_boundary(self) -> bool: |
| 1666 | return ( |
| 1667 | (self.position < len(self.source) and self.source[self.position] == "&") |
| 1668 | or self.source.startswith("\\\\", self.position) |
| 1669 | or self._at_control_word("cr") |
| 1670 | or self._at_control_word("end") |
| 1671 | ) |
| 1672 | |
| 1673 | def _parse_text_embedded_math( |
| 1674 | self, |
| 1675 | opener: str, |
| 1676 | closer: str, |
| 1677 | *, |
| 1678 | opened: bool = False, |
| 1679 | ) -> Sequence: |
| 1680 | start = self.position if opened else self.position + len(opener) |
| 1681 | if not opened: |
| 1682 | self.position += len(opener) |
| 1683 | closing = self.source.find(closer, self.position) |
| 1684 | if closing < 0: |
| 1685 | self._fail(f"Unclosed embedded math delimiter {opener!r}", position=start) |
| 1686 | raw = self.source[self.position:closing] |
| 1687 | self.position = closing + len(closer) |
| 1688 | embedded = _LatexParser( |
| 1689 | raw, |
| 1690 | display=False, |
| 1691 | inherited_style=self.current_style, |
| 1692 | ).parse() |
| 1693 | return Sequence((Styled(embedded, _MATH_MODE_RESET_STYLE),)) |
| 1694 | |
| 1695 | def _parse_fragment(self, raw: str) -> Sequence: |
| 1696 | if not raw: |
| 1697 | return Sequence(()) |
| 1698 | return _LatexParser( |
| 1699 | raw, |
| 1700 | display=self.display, |
| 1701 | text_mode=bool(self.text_mode_depth), |
| 1702 | inherited_style=self.current_style, |
| 1703 | ).parse() |
| 1704 | |
| 1705 | def _parse_spacing_length(self, command: str) -> str: |
| 1706 | self._skip_whitespace() |
| 1707 | match = _LENGTH_RE.match(self.source, self.position) |
| 1708 | if match is None: |
| 1709 | self._fail(f"\\{command} requires a numeric length with mu/em/ex/pt") |
| 1710 | self.position = match.end() |
| 1711 | self._skip_whitespace() |
| 1712 | return _space_from_length(match.group(0)) |
| 1713 | |
| 1714 | def _parse_color(self) -> str: |
| 1715 | raw = self._parse_raw_required_group("formula color").strip() |
| 1716 | if _COLOR_HEX_RE.fullmatch(raw): |
| 1717 | return raw[1:].upper() |
| 1718 | color = COLOR_NAMES.get(raw.lower()) |
| 1719 | if color is None: |
| 1720 | self._fail(f"Unsupported formula color {raw!r}") |
| 1721 | return color |
| 1722 | |
| 1723 | def _delimiter_from_raw(self, raw: str) -> str: |
| 1724 | raw = raw.strip() |
| 1725 | if raw in {"", "."}: |
| 1726 | return "" |
| 1727 | if raw in "()[]|{}⟨⟩⌊⌋⌈⌉⟦⟧": |
| 1728 | return raw |
| 1729 | control_symbols = {r"\{": "{", r"\}": "}", r"\|": "‖"} |
| 1730 | if raw in control_symbols: |
| 1731 | return control_symbols[raw] |
| 1732 | if raw.startswith("\\"): |
| 1733 | command = raw[1:] |
| 1734 | if command in DELIMITER_COMMANDS: |
| 1735 | return DELIMITER_COMMANDS[command] |
| 1736 | self._fail(f"Unsupported generalized-fraction delimiter {raw!r}") |
| 1737 | |
| 1738 | def _roman_name(self, name: str) -> Sequence: |
| 1739 | return Sequence((Text(name, _ROMAN_STYLE),)) |
| 1740 | |
| 1741 | def _single_node(self, sequence: Sequence) -> Node: |
| 1742 | if len(sequence.children) == 1: |
| 1743 | return sequence.children[0] |
| 1744 | return sequence |
| 1745 | |
| 1746 | def _styled_text( |
| 1747 | self, |
| 1748 | value: str, |
| 1749 | style: RunStyle | None = None, |
| 1750 | *, |
| 1751 | literal: bool = False, |
| 1752 | ) -> Text: |
| 1753 | return Text( |
| 1754 | value, |
| 1755 | merge_run_styles(self.current_style, style), |
| 1756 | literal=literal, |
| 1757 | ) |
| 1758 | |
| 1759 | def _current_infix_command(self) -> str | None: |
| 1760 | for command in _INFIX_FRACTIONS: |
| 1761 | if self._at_control_word(command): |
| 1762 | return command |
| 1763 | return None |
| 1764 | |
| 1765 | def _at_control_word(self, expected: str) -> bool: |
| 1766 | prefix = f"\\{expected}" |
| 1767 | if not self.source.startswith(prefix, self.position): |
| 1768 | return False |
| 1769 | following = self.position + len(prefix) |
| 1770 | return following >= len(self.source) or not _is_command_letter(self.source[following]) |
| 1771 | |
| 1772 | def _consume_control_word(self, expected: str) -> None: |
| 1773 | if not self._at_control_word(expected): |
| 1774 | self._fail(f"Expected \\{expected}") |
| 1775 | self.position += len(expected) + 1 |
| 1776 | self._skip_whitespace() |
| 1777 | |
| 1778 | def _read_control_word_body(self) -> str: |
| 1779 | start = self.position |
| 1780 | while self.position < len(self.source) and _is_command_letter(self.source[self.position]): |
| 1781 | self.position += 1 |
| 1782 | return self.source[start:self.position] |
| 1783 | |
| 1784 | def _skip_whitespace(self) -> None: |
| 1785 | self.position = _skip_whitespace(self.source, self.position) |
| 1786 | |
| 1787 | def _fail(self, message: str, *, position: int | None = None) -> None: |
| 1788 | offset = self.position if position is None else position |
| 1789 | start = max(0, offset - 16) |
| 1790 | end = min(len(self.source), offset + 16) |
| 1791 | context = self.source[start:end].replace("\n", " ") |
| 1792 | raise FormulaCompileError(f"{message} at offset {offset}: {context!r}") |
| 1793 | |
| 1794 | |
| 1795 | _STYLE_COLOR_COMMANDS = frozenset({"color", "textcolor"}) |
| 1796 | |
| 1797 | |
| 1798 | class _ChemParser: |
| 1799 | """Parse the documented Microsoft 365 mhchem subset into shared AST nodes.""" |
| 1800 | |
| 1801 | _ARROWS = { |
| 1802 | "<-->": "⟷", |
| 1803 | "<=>": "⇌", |
| 1804 | "<->": "↔", |
| 1805 | "->": "→", |
| 1806 | "<-": "←", |
| 1807 | } |
| 1808 | _UNSUPPORTED_AT_LABEL_RE = re.compile(r"@[<>=-]+\{") |
| 1809 | |
| 1810 | def __init__(self, source: str, *, display: bool) -> None: |
| 1811 | self.source = source |
| 1812 | self.position = 0 |
| 1813 | self.display = display |
| 1814 | |
| 1815 | def parse(self) -> Sequence: |
| 1816 | children: list[Node] = [] |
| 1817 | while self.position < len(self.source): |
| 1818 | if self._UNSUPPORTED_AT_LABEL_RE.match(self.source, self.position): |
| 1819 | raise FormulaCompileError( |
| 1820 | "mhchem @{} arrow labels are unsupported; use [above][below]" |
| 1821 | ) |
| 1822 | self._reject_unsupported_arrow() |
| 1823 | arrow = self._match_arrow() |
| 1824 | if arrow is not None: |
| 1825 | append_child(children, arrow) |
| 1826 | continue |
| 1827 | char = self.source[self.position] |
| 1828 | if char.isspace(): |
| 1829 | while self.position < len(self.source) and self.source[self.position].isspace(): |
| 1830 | self.position += 1 |
| 1831 | append_child(children, Text(" ", _TEXT_STYLE)) |
| 1832 | continue |
| 1833 | if char == "\\": |
| 1834 | parser = _LatexParser(self.source[self.position:], display=self.display) |
| 1835 | node = parser._parse_complete_atom() |
| 1836 | self.position += parser.position |
| 1837 | append_child(children, node) |
| 1838 | continue |
| 1839 | if char == "{": |
| 1840 | raw, self.position = _read_raw_group(self.source, self.position) |
| 1841 | if raw in {"(", ")", "[", "]"}: |
| 1842 | append_child(children, Text(raw, _ROMAN_STYLE)) |
| 1843 | continue |
| 1844 | body = _ChemParser(raw, display=self.display).parse() |
| 1845 | append_child(children, body) |
| 1846 | continue |
| 1847 | if char in "([": |
| 1848 | append_child(children, self._parse_grouped_formula(char)) |
| 1849 | continue |
| 1850 | if char.isupper(): |
| 1851 | append_child(children, self._parse_element()) |
| 1852 | continue |
| 1853 | if char.isdigit(): |
| 1854 | append_child(children, self._parse_number(children)) |
| 1855 | continue |
| 1856 | if char == "^" and self._standalone_marker(): |
| 1857 | self.position += 1 |
| 1858 | append_child(children, Text("↑", _ROMAN_STYLE)) |
| 1859 | continue |
| 1860 | if char in "^_": |
| 1861 | if self._has_right_script_base(children): |
| 1862 | base = children.pop() |
| 1863 | append_child(children, self._parse_explicit_scripts(base)) |
| 1864 | else: |
| 1865 | append_child(children, self._parse_isotope()) |
| 1866 | continue |
| 1867 | if char in "+-": |
| 1868 | if self._is_bond_dash(): |
| 1869 | self.position += 1 |
| 1870 | append_child(children, Text("‒", _ROMAN_STYLE)) |
| 1871 | elif ( |
| 1872 | children |
| 1873 | and self.position > 0 |
| 1874 | and not self.source[self.position - 1].isspace() |
| 1875 | ): |
| 1876 | self._attach_charge(children) |
| 1877 | else: |
| 1878 | self.position += 1 |
| 1879 | append_child(children, Text("+" if char == "+" else "−", _ROMAN_STYLE)) |
| 1880 | continue |
| 1881 | if char == "*": |
| 1882 | self.position += 1 |
| 1883 | append_child(children, Text("·", _ROMAN_STYLE)) |
| 1884 | continue |
| 1885 | if char == "=": |
| 1886 | self.position += 1 |
| 1887 | append_child(children, Text("=", _ROMAN_STYLE)) |
| 1888 | continue |
| 1889 | if char == "v" and self._standalone_marker(): |
| 1890 | self.position += 1 |
| 1891 | append_child(children, Text("↓", _ROMAN_STYLE)) |
| 1892 | continue |
| 1893 | if char.islower(): |
| 1894 | start = self.position |
| 1895 | while self.position < len(self.source) and self.source[self.position].islower(): |
| 1896 | self.position += 1 |
| 1897 | word = self.source[start:self.position] |
| 1898 | following = self.position |
| 1899 | while following < len(self.source) and self.source[following].isspace(): |
| 1900 | following += 1 |
| 1901 | is_variable = ( |
| 1902 | len(word) == 1 |
| 1903 | and following < len(self.source) |
| 1904 | and self.source[following].isupper() |
| 1905 | ) |
| 1906 | style = None if is_variable else _ROMAN_STYLE |
| 1907 | append_child(children, Text(word, style)) |
| 1908 | continue |
| 1909 | self.position += 1 |
| 1910 | append_child(children, Text("−" if char == "-" else char, _ROMAN_STYLE)) |
| 1911 | return Sequence(tuple(children)) |
| 1912 | |
| 1913 | def _parse_element(self) -> Node: |
| 1914 | start = self.position |
| 1915 | self.position += 1 |
| 1916 | while self.position < len(self.source) and self.source[self.position].islower(): |
| 1917 | self.position += 1 |
| 1918 | base: Node = Text(self.source[start:self.position], _ROMAN_STYLE) |
| 1919 | if self.position < len(self.source) and self.source[self.position].isdigit(): |
| 1920 | digits = self._read_digits() |
| 1921 | base = Script(base, subscript=Sequence((Text(digits, _ROMAN_STYLE),))) |
| 1922 | if self.position < len(self.source) and self.source[self.position] in "^_": |
| 1923 | base = self._parse_explicit_scripts(base) |
| 1924 | if ( |
| 1925 | self.position < len(self.source) |
| 1926 | and self.source[self.position] in "+-" |
| 1927 | and not self._is_bond_dash() |
| 1928 | ): |
| 1929 | charge = self._read_charge() |
| 1930 | base = self._merge_script( |
| 1931 | base, |
| 1932 | superscript=Sequence((Text(charge, _ROMAN_STYLE),)), |
| 1933 | ) |
| 1934 | return base |
| 1935 | |
| 1936 | def _parse_number(self, children: list[Node]) -> Node: |
| 1937 | start = self.position |
| 1938 | numerator = self._read_digits() |
| 1939 | number: Node = Text(numerator, _ROMAN_STYLE) |
| 1940 | if self.position < len(self.source) and self.source[self.position] == "/": |
| 1941 | saved = self.position |
| 1942 | self.position += 1 |
| 1943 | if self.position < len(self.source) and self.source[self.position].isdigit(): |
| 1944 | denominator = self._read_digits() |
| 1945 | number = Fraction( |
| 1946 | Sequence((Text(numerator, _ROMAN_STYLE),)), |
| 1947 | Sequence((Text(denominator, _ROMAN_STYLE),)), |
| 1948 | ) |
| 1949 | else: |
| 1950 | self.position = saved |
| 1951 | if self._is_coefficient_position(start): |
| 1952 | following = self.position |
| 1953 | while following < len(self.source) and self.source[following].isspace(): |
| 1954 | following += 1 |
| 1955 | if following < len(self.source) and self.source[following].isupper(): |
| 1956 | self.position = following |
| 1957 | return Sequence((number, Text("\u2009", _SPACING_STYLE))) |
| 1958 | return number |
| 1959 | |
| 1960 | def _parse_grouped_formula(self, opener: str) -> Node: |
| 1961 | closer = ")" if opener == "(" else "]" |
| 1962 | start = self.position + 1 |
| 1963 | depth = 1 |
| 1964 | cursor = start |
| 1965 | while cursor < len(self.source): |
| 1966 | if self.source[cursor] == opener: |
| 1967 | depth += 1 |
| 1968 | elif self.source[cursor] == closer: |
| 1969 | depth -= 1 |
| 1970 | if depth == 0: |
| 1971 | break |
| 1972 | cursor += 1 |
| 1973 | if cursor >= len(self.source): |
| 1974 | raise FormulaCompileError(f"Unclosed chemical delimiter {opener!r}") |
| 1975 | body = _ChemParser(self.source[start:cursor], display=self.display).parse() |
| 1976 | self.position = cursor + 1 |
| 1977 | base: Node = Sequence(( |
| 1978 | Text(opener, _ROMAN_STYLE), |
| 1979 | *body.children, |
| 1980 | Text(closer, _ROMAN_STYLE), |
| 1981 | )) |
| 1982 | if self.position < len(self.source) and self.source[self.position].isdigit(): |
| 1983 | digits = self._read_digits() |
| 1984 | if self.position < len(self.source) and self.source[self.position] in "+-": |
| 1985 | charge = digits + self._read_charge() |
| 1986 | base = Script( |
| 1987 | base, |
| 1988 | superscript=Sequence((Text(charge, _ROMAN_STYLE),)), |
| 1989 | ) |
| 1990 | else: |
| 1991 | base = Script(base, subscript=Sequence((Text(digits, _ROMAN_STYLE),))) |
| 1992 | if self.position < len(self.source) and self.source[self.position] in "+-": |
| 1993 | charge = self._read_charge() |
| 1994 | base = self._merge_script( |
| 1995 | base, |
| 1996 | superscript=Sequence((Text(charge, _ROMAN_STYLE),)), |
| 1997 | ) |
| 1998 | return base |
| 1999 | |
| 2000 | def _parse_isotope(self) -> Prescript: |
| 2001 | subscript: Sequence | None = None |
| 2002 | superscript: Sequence | None = None |
| 2003 | while self.position < len(self.source) and self.source[self.position] in "^_": |
| 2004 | marker = self.source[self.position] |
| 2005 | self.position += 1 |
| 2006 | raw = self._read_chem_script() |
| 2007 | value = self._chem_script_sequence(raw) |
| 2008 | if marker == "_": |
| 2009 | subscript = value |
| 2010 | else: |
| 2011 | superscript = value |
| 2012 | if self.position >= len(self.source) or not self.source[self.position].isupper(): |
| 2013 | raise FormulaCompileError("Chemical pre-script requires an element base") |
| 2014 | base = self._parse_element() |
| 2015 | return Prescript(base, subscript=subscript, superscript=superscript) |
| 2016 | |
| 2017 | def _parse_explicit_scripts(self, base: Node) -> Script: |
| 2018 | subscript: Sequence | None = None |
| 2019 | superscript: Sequence | None = None |
| 2020 | while self.position < len(self.source) and self.source[self.position] in "^_": |
| 2021 | marker = self.source[self.position] |
| 2022 | self.position += 1 |
| 2023 | raw = self._read_chem_script() |
| 2024 | if ( |
| 2025 | marker == "^" |
| 2026 | and self.position < len(self.source) |
| 2027 | and self.source[self.position] in "+-" |
| 2028 | ): |
| 2029 | raw += self._read_charge() |
| 2030 | value = self._chem_script_sequence(raw) |
| 2031 | if marker == "_": |
| 2032 | subscript = value |
| 2033 | else: |
| 2034 | superscript = value |
| 2035 | return self._merge_script( |
| 2036 | base, |
| 2037 | subscript=subscript, |
| 2038 | superscript=superscript, |
| 2039 | ) |
| 2040 | |
| 2041 | def _read_chem_script(self) -> str: |
| 2042 | if self.position >= len(self.source): |
| 2043 | raise FormulaCompileError("Chemical script is missing an argument") |
| 2044 | if self.source[self.position] == "{": |
| 2045 | raw, self.position = _read_raw_group(self.source, self.position) |
| 2046 | return raw |
| 2047 | char = self.source[self.position] |
| 2048 | self.position += 1 |
| 2049 | return char |
| 2050 | |
| 2051 | def _attach_charge(self, children: list[Node]) -> None: |
| 2052 | charge = self._read_charge() |
| 2053 | base = children.pop() |
| 2054 | children.append(self._merge_script( |
| 2055 | base, |
| 2056 | superscript=Sequence((Text(charge, _ROMAN_STYLE),)), |
| 2057 | )) |
| 2058 | |
| 2059 | def _merge_script( |
| 2060 | self, |
| 2061 | base: Node, |
| 2062 | *, |
| 2063 | subscript: Sequence | None = None, |
| 2064 | superscript: Sequence | None = None, |
| 2065 | ) -> Script: |
| 2066 | if isinstance(base, Script): |
| 2067 | return Script( |
| 2068 | base.base, |
| 2069 | subscript or base.subscript, |
| 2070 | superscript or base.superscript, |
| 2071 | ) |
| 2072 | return Script(base, subscript=subscript, superscript=superscript) |
| 2073 | |
| 2074 | def _chem_script_sequence(self, raw: str) -> Sequence: |
| 2075 | if "\\" in raw: |
| 2076 | return _LatexParser(raw, display=self.display).parse() |
| 2077 | normalized = raw.replace("-", "−") |
| 2078 | style = None if len(normalized) == 1 and normalized.islower() else _ROMAN_STYLE |
| 2079 | return Sequence((Text(normalized, style),)) |
| 2080 | |
| 2081 | def _has_right_script_base(self, children: list[Node]) -> bool: |
| 2082 | if not children or self.position == 0: |
| 2083 | return False |
| 2084 | previous = self.source[self.position - 1] |
| 2085 | if previous.isspace() or previous in "+-=<>*/([{,;:": |
| 2086 | return False |
| 2087 | return not isinstance(children[-1], Limit) |
| 2088 | |
| 2089 | def _is_coefficient_position(self, start: int) -> bool: |
| 2090 | cursor = start - 1 |
| 2091 | while cursor >= 0 and self.source[cursor].isspace(): |
| 2092 | cursor -= 1 |
| 2093 | return cursor < 0 or self.source[cursor] in "+<>=-" |
| 2094 | |
| 2095 | def _is_bond_dash(self) -> bool: |
| 2096 | return ( |
| 2097 | self.position < len(self.source) |
| 2098 | and self.source[self.position] == "-" |
| 2099 | and self.position + 1 < len(self.source) |
| 2100 | and self.source[self.position + 1].isupper() |
| 2101 | ) |
| 2102 | |
| 2103 | def _read_charge(self) -> str: |
| 2104 | start = self.position |
| 2105 | while self.position < len(self.source) and self.source[self.position] in "+-": |
| 2106 | self.position += 1 |
| 2107 | return self.source[start:self.position].replace("-", "−") |
| 2108 | |
| 2109 | def _read_digits(self) -> str: |
| 2110 | start = self.position |
| 2111 | while self.position < len(self.source) and self.source[self.position].isdigit(): |
| 2112 | self.position += 1 |
| 2113 | return self.source[start:self.position] |
| 2114 | |
| 2115 | def _match_arrow(self) -> Node | None: |
| 2116 | for token, symbol in self._ARROWS.items(): |
| 2117 | if not self.source.startswith(token, self.position): |
| 2118 | continue |
| 2119 | self.position += len(token) |
| 2120 | upper = self._read_arrow_label() |
| 2121 | lower = self._read_arrow_label() |
| 2122 | return Limit(Text(symbol, _ROMAN_STYLE), lower=lower, upper=upper) |
| 2123 | return None |
| 2124 | |
| 2125 | def _reject_unsupported_arrow(self) -> None: |
| 2126 | for token in ("<<=>>", "<=>>", "<<=>", "->>"): |
| 2127 | if self.source.startswith(token, self.position): |
| 2128 | raise FormulaCompileError( |
| 2129 | f"Unsupported chemical reaction arrow {token!r}" |
| 2130 | ) |
| 2131 | |
| 2132 | def _read_arrow_label(self) -> Sequence | None: |
| 2133 | if self.position >= len(self.source) or self.source[self.position] != "[": |
| 2134 | return None |
| 2135 | start = self.position + 1 |
| 2136 | depth = 1 |
| 2137 | brace_depth = 0 |
| 2138 | cursor = start |
| 2139 | while cursor < len(self.source): |
| 2140 | char = self.source[cursor] |
| 2141 | if char == "\\": |
| 2142 | cursor += 2 |
| 2143 | continue |
| 2144 | if char == "{": |
| 2145 | brace_depth += 1 |
| 2146 | elif char == "}" and brace_depth: |
| 2147 | brace_depth -= 1 |
| 2148 | elif brace_depth == 0 and char == "[": |
| 2149 | depth += 1 |
| 2150 | elif brace_depth == 0 and char == "]": |
| 2151 | depth -= 1 |
| 2152 | if depth == 0: |
| 2153 | raw = self.source[start:cursor] |
| 2154 | self.position = cursor + 1 |
| 2155 | return _ChemParser(raw, display=self.display).parse() |
| 2156 | cursor += 1 |
| 2157 | raise FormulaCompileError("Unclosed chemical arrow label") |
| 2158 | |
| 2159 | def _standalone_marker(self) -> bool: |
| 2160 | before = self.position == 0 or self.source[self.position - 1].isspace() |
| 2161 | after_index = self.position + 1 |
| 2162 | after = after_index >= len(self.source) or self.source[after_index].isspace() |
| 2163 | return before and after |
| 2164 | |
| 2165 | |
| 2166 | def parse_latex_formula(latex: str, *, display: bool) -> Sequence: |
| 2167 | """Validate, normalize, and parse one Microsoft 365 LaTeX expression.""" |
| 2168 | if not isinstance(latex, str): |
| 2169 | raise FormulaCompileError("LaTeX formula must be a string") |
| 2170 | source = latex.strip() |
| 2171 | if not source: |
| 2172 | raise FormulaCompileError("LaTeX formula is empty") |
| 2173 | if any(not _xml_character_allowed(char) for char in source): |
| 2174 | raise FormulaCompileError("LaTeX formula contains an invalid XML character") |
| 2175 | prepared = _prepare_source(source) |
| 2176 | if not prepared: |
| 2177 | raise FormulaCompileError("LaTeX formula is empty after preprocessing") |
| 2178 | return _LatexParser(prepared, display=display).parse() |
| 2179 | |
| 2180 | |
| 2181 | __all__ = ["FormulaCompileError", "parse_latex_formula"] |
| 2182 |