Mini Shell
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)
Zerion Mini Shell 1.0