JezK
Edit File: markup.py
import re from ast import literal_eval from operator import attrgetter from typing import Callable, Iterable, List, Match, NamedTuple, Optional, Tuple, Union from ._emoji_replace import _emoji_replace from .emoji import EmojiVariant from .errors import MarkupError from .style import Style from .text import Span, Text RE_TAGS = re.compile( r"""((\\*)\[([a-z#/@][^[]*?)])""", re.VERBOSE, ) RE_HANDLER = re.compile(r"^([\w.]*?)(\(.*?\))?$") class Tag(NamedTuple): """A tag in console markup.""" name: str """The tag name. e.g. 'bold'.""" parameters: Optional[str] """Any additional parameters after the name.""" def __str__(self) -> str: return ( self.name if self.parameters is None else f"{self.name} {self.parameters}" ) @property def markup(self) -> str: """Get the string representation of this tag.""" return ( f"[{self.name}]" if self.parameters is None else f"[{self.name}={self.parameters}]" ) _ReStringMatch = Match[str] # regex match object _ReSubCallable = Callable[[_ReStringMatch], str] # Callable invoked by re.sub _EscapeSubMethod = Callable[[_ReSubCallable, str], str] # Sub method of a compiled re def escape( markup: str, _escape: _EscapeSubMethod = re.compile(r"(\\*)(\[[a-z#/@][^[]*?])").sub, ) -> str: """Escapes text so that it won't be interpreted as markup. Args: markup (str): Content to be inserted in to markup. Returns: str: Markup with square brackets escaped. """ def escape_backslashes(match: Match[str]) -> str: """Called by re.sub replace matches.""" backslashes, text = match.groups() return f"{backslashes}{backslashes}\\{text}" markup = _escape(escape_backslashes, markup) return markup def _parse(markup: str) -> Iterable[Tuple[int, Optional[str], Optional[Tag]]]: """Parse markup in to an iterable of tuples of (position, text, tag). Args: markup (str): A string containing console markup """ position = 0 _divmod = divmod _Tag = Tag for match in RE_TAGS.finditer(markup): full_text, escapes, tag_text = match.groups() start, end = match.span() if start > position: yield start, markup[position:start], None if escapes: backslashes, escaped = _divmod(len(escapes), 2) if backslashes: # Literal backslashes yield start, "\\" * backslashes, None start += backslashes * 2 if escaped: # Escape of tag yield start, full_text[len(escapes) :], None position = end continue text, equals, parameters = tag_text.partition("=") yield start, None, _Tag(text, parameters if equals else None) position = end if position < len(markup): yield position, markup[position:], None def render( markup: str, style: Union[str, Style] = "", emoji: bool = True, emoji_variant: Optional[EmojiVariant] = None, ) -> Text: """Render console markup in to a Text instance. Args: markup (str): A string containing console markup. emoji (bool, optional): Also render emoji code. Defaults to True. Raises: MarkupError: If there is a syntax error in the markup. Returns: Text: A test instance. """ emoji_replace = _emoji_replace if "[" not in markup: return Text( emoji_replace(markup, default_variant=emoji_variant) if emoji else markup, style=style, ) text = Text(style=style) append = text.append normalize = Style.normalize style_stack: List[Tuple[int, Tag]] = [] pop = style_stack.pop spans: List[Span] = [] append_span = spans.append _Span = Span _Tag = Tag def pop_style(style_name: str) -> Tuple[int, Tag]: """Pop tag matching given style name.""" for index, (_, tag) in enumerate(reversed(style_stack), 1): if tag.name == style_name: return pop(-index) raise KeyError(style_name) for position, plain_text, tag in _parse(markup): if plain_text is not None: # Handle open brace escapes, where the brace is not part of a tag. plain_text = plain_text.replace("\\[", "[") append(emoji_replace(plain_text) if emoji else plain_text) elif tag is not None: if tag.name.startswith("/"): # Closing tag style_name = tag.name[1:].strip() if style_name: # explicit close style_name = normalize(style_name) try: start, open_tag = pop_style(style_name) except KeyError: raise MarkupError( f"closing tag '{tag.markup}' at position {position} doesn't match any open tag" ) from None else: # implicit close try: start, open_tag = pop() except IndexError: raise MarkupError( f"closing tag '[/]' at position {position} has nothing to close" ) from None if open_tag.name.startswith("@"): if open_tag.parameters: handler_name = "" parameters = open_tag.parameters.strip() handler_match = RE_HANDLER.match(parameters) if handler_match is not None: handler_name, match_parameters = handler_match.groups() parameters = ( "()" if match_parameters is None else match_parameters ) try: meta_params = literal_eval(parameters) except SyntaxError as error: raise MarkupError( f"error parsing {parameters!r} in {open_tag.parameters!r}; {error.msg}" ) except Exception as error: raise MarkupError( f"error parsing {open_tag.parameters!r}; {error}" ) from None if handler_name: meta_params = ( handler_name, meta_params if isinstance(meta_params, tuple) else (meta_params,), ) else: meta_params = () append_span( _Span( start, len(text), Style(meta={open_tag.name: meta_params}) ) ) else: append_span(_Span(start, len(text), str(open_tag))) else: # Opening tag normalized_tag = _Tag(normalize(tag.name), tag.parameters) style_stack.append((len(text), normalized_tag)) text_length = len(text) while style_stack: start, tag = style_stack.pop() style = str(tag) if style: append_span(_Span(start, text_length, style)) text.spans = sorted(spans[::-1], key=attrgetter("start")) return text if __name__ == "__main__": # pragma: no cover MARKUP = [ "[red]Hello World[/red]", "[magenta]Hello [b]World[/b]", "[bold]Bold[italic] bold and italic [/bold]italic[/italic]", "Click [link=https://www.willmcgugan.com]here[/link] to visit my Blog", ":warning-emoji: [bold red blink] DANGER![/]", ] from pip._vendor.rich import print from pip._vendor.rich.table import Table grid = Table("Markup", "Result", padding=(0, 1)) for markup in MARKUP: grid.add_row(Text(markup), markup) print(grid)