335 lines
12 KiB
Python
335 lines
12 KiB
Python
"""
|
|
Adaptor classes for using Pygments lexers within prompt_toolkit.
|
|
|
|
This includes syntax synchronization code, so that we don't have to start
|
|
lexing at the beginning of a document, when displaying a very large text.
|
|
"""
|
|
import re
|
|
from abc import ABCMeta, abstractmethod
|
|
from typing import (
|
|
TYPE_CHECKING,
|
|
Callable,
|
|
Dict,
|
|
Generator,
|
|
Iterable,
|
|
Optional,
|
|
Tuple,
|
|
Type,
|
|
)
|
|
|
|
from prompt_toolkit.document import Document
|
|
from prompt_toolkit.filters import FilterOrBool, to_filter
|
|
from prompt_toolkit.formatted_text.base import StyleAndTextTuples
|
|
from prompt_toolkit.formatted_text.utils import split_lines
|
|
from prompt_toolkit.styles.pygments import pygments_token_to_classname
|
|
|
|
from .base import Lexer, SimpleLexer
|
|
|
|
if TYPE_CHECKING:
|
|
from pygments.lexer import Lexer as PygmentsLexerCls
|
|
|
|
__all__ = [
|
|
"PygmentsLexer",
|
|
"SyntaxSync",
|
|
"SyncFromStart",
|
|
"RegexSync",
|
|
]
|
|
|
|
|
|
class SyntaxSync(metaclass=ABCMeta):
|
|
"""
|
|
Syntax synchroniser. This is a tool that finds a start position for the
|
|
lexer. This is especially important when editing big documents; we don't
|
|
want to start the highlighting by running the lexer from the beginning of
|
|
the file. That is very slow when editing.
|
|
"""
|
|
|
|
@abstractmethod
|
|
def get_sync_start_position(
|
|
self, document: Document, lineno: int
|
|
) -> Tuple[int, int]:
|
|
"""
|
|
Return the position from where we can start lexing as a (row, column)
|
|
tuple.
|
|
|
|
:param document: `Document` instance that contains all the lines.
|
|
:param lineno: The line that we want to highlight. (We need to return
|
|
this line, or an earlier position.)
|
|
"""
|
|
|
|
|
|
class SyncFromStart(SyntaxSync):
|
|
"""
|
|
Always start the syntax highlighting from the beginning.
|
|
"""
|
|
|
|
def get_sync_start_position(
|
|
self, document: Document, lineno: int
|
|
) -> Tuple[int, int]:
|
|
return 0, 0
|
|
|
|
|
|
class RegexSync(SyntaxSync):
|
|
"""
|
|
Synchronize by starting at a line that matches the given regex pattern.
|
|
"""
|
|
|
|
# Never go more than this amount of lines backwards for synchronisation.
|
|
# That would be too CPU intensive.
|
|
MAX_BACKWARDS = 500
|
|
|
|
# Start lexing at the start, if we are in the first 'n' lines and no
|
|
# synchronisation position was found.
|
|
FROM_START_IF_NO_SYNC_POS_FOUND = 100
|
|
|
|
def __init__(self, pattern: str) -> None:
|
|
self._compiled_pattern = re.compile(pattern)
|
|
|
|
def get_sync_start_position(
|
|
self, document: Document, lineno: int
|
|
) -> Tuple[int, int]:
|
|
"""
|
|
Scan backwards, and find a possible position to start.
|
|
"""
|
|
pattern = self._compiled_pattern
|
|
lines = document.lines
|
|
|
|
# Scan upwards, until we find a point where we can start the syntax
|
|
# synchronisation.
|
|
for i in range(lineno, max(-1, lineno - self.MAX_BACKWARDS), -1):
|
|
match = pattern.match(lines[i])
|
|
if match:
|
|
return i, match.start()
|
|
|
|
# No synchronisation point found. If we aren't that far from the
|
|
# beginning, start at the very beginning, otherwise, just try to start
|
|
# at the current line.
|
|
if lineno < self.FROM_START_IF_NO_SYNC_POS_FOUND:
|
|
return 0, 0
|
|
else:
|
|
return lineno, 0
|
|
|
|
@classmethod
|
|
def from_pygments_lexer_cls(cls, lexer_cls: "PygmentsLexerCls") -> "RegexSync":
|
|
"""
|
|
Create a :class:`.RegexSync` instance for this Pygments lexer class.
|
|
"""
|
|
patterns = {
|
|
# For Python, start highlighting at any class/def block.
|
|
"Python": r"^\s*(class|def)\s+",
|
|
"Python 3": r"^\s*(class|def)\s+",
|
|
# For HTML, start at any open/close tag definition.
|
|
"HTML": r"<[/a-zA-Z]",
|
|
# For javascript, start at a function.
|
|
"JavaScript": r"\bfunction\b"
|
|
# TODO: Add definitions for other languages.
|
|
# By default, we start at every possible line.
|
|
}
|
|
p = patterns.get(lexer_cls.name, "^")
|
|
return cls(p)
|
|
|
|
|
|
class _TokenCache(Dict[Tuple[str, ...], str]):
|
|
"""
|
|
Cache that converts Pygments tokens into `prompt_toolkit` style objects.
|
|
|
|
``Token.A.B.C`` will be converted into:
|
|
``class:pygments,pygments.A,pygments.A.B,pygments.A.B.C``
|
|
"""
|
|
|
|
def __missing__(self, key: Tuple[str, ...]) -> str:
|
|
result = "class:" + pygments_token_to_classname(key)
|
|
self[key] = result
|
|
return result
|
|
|
|
|
|
_token_cache = _TokenCache()
|
|
|
|
|
|
class PygmentsLexer(Lexer):
|
|
"""
|
|
Lexer that calls a pygments lexer.
|
|
|
|
Example::
|
|
|
|
from pygments.lexers.html import HtmlLexer
|
|
lexer = PygmentsLexer(HtmlLexer)
|
|
|
|
Note: Don't forget to also load a Pygments compatible style. E.g.::
|
|
|
|
from prompt_toolkit.styles.from_pygments import style_from_pygments_cls
|
|
from pygments.styles import get_style_by_name
|
|
style = style_from_pygments_cls(get_style_by_name('monokai'))
|
|
|
|
:param pygments_lexer_cls: A `Lexer` from Pygments.
|
|
:param sync_from_start: Start lexing at the start of the document. This
|
|
will always give the best results, but it will be slow for bigger
|
|
documents. (When the last part of the document is display, then the
|
|
whole document will be lexed by Pygments on every key stroke.) It is
|
|
recommended to disable this for inputs that are expected to be more
|
|
than 1,000 lines.
|
|
:param syntax_sync: `SyntaxSync` object.
|
|
"""
|
|
|
|
# Minimum amount of lines to go backwards when starting the parser.
|
|
# This is important when the lines are retrieved in reverse order, or when
|
|
# scrolling upwards. (Due to the complexity of calculating the vertical
|
|
# scroll offset in the `Window` class, lines are not always retrieved in
|
|
# order.)
|
|
MIN_LINES_BACKWARDS = 50
|
|
|
|
# When a parser was started this amount of lines back, read the parser
|
|
# until we get the current line. Otherwise, start a new parser.
|
|
# (This should probably be bigger than MIN_LINES_BACKWARDS.)
|
|
REUSE_GENERATOR_MAX_DISTANCE = 100
|
|
|
|
def __init__(
|
|
self,
|
|
pygments_lexer_cls: Type["PygmentsLexerCls"],
|
|
sync_from_start: FilterOrBool = True,
|
|
syntax_sync: Optional[SyntaxSync] = None,
|
|
) -> None:
|
|
|
|
self.pygments_lexer_cls = pygments_lexer_cls
|
|
self.sync_from_start = to_filter(sync_from_start)
|
|
|
|
# Instantiate the Pygments lexer.
|
|
self.pygments_lexer = pygments_lexer_cls(
|
|
stripnl=False, stripall=False, ensurenl=False
|
|
)
|
|
|
|
# Create syntax sync instance.
|
|
self.syntax_sync = syntax_sync or RegexSync.from_pygments_lexer_cls(
|
|
pygments_lexer_cls
|
|
)
|
|
|
|
@classmethod
|
|
def from_filename(
|
|
cls, filename: str, sync_from_start: FilterOrBool = True
|
|
) -> "Lexer":
|
|
"""
|
|
Create a `Lexer` from a filename.
|
|
"""
|
|
# Inline imports: the Pygments dependency is optional!
|
|
from pygments.lexers import get_lexer_for_filename
|
|
from pygments.util import ClassNotFound
|
|
|
|
try:
|
|
pygments_lexer = get_lexer_for_filename(filename)
|
|
except ClassNotFound:
|
|
return SimpleLexer()
|
|
else:
|
|
return cls(pygments_lexer.__class__, sync_from_start=sync_from_start)
|
|
|
|
def lex_document(self, document: Document) -> Callable[[int], StyleAndTextTuples]:
|
|
"""
|
|
Create a lexer function that takes a line number and returns the list
|
|
of (style_str, text) tuples as the Pygments lexer returns for that line.
|
|
"""
|
|
LineGenerator = Generator[Tuple[int, StyleAndTextTuples], None, None]
|
|
|
|
# Cache of already lexed lines.
|
|
cache: Dict[int, StyleAndTextTuples] = {}
|
|
|
|
# Pygments generators that are currently lexing.
|
|
# Map lexer generator to the line number.
|
|
line_generators: Dict[LineGenerator, int] = {}
|
|
|
|
def get_syntax_sync() -> SyntaxSync:
|
|
" The Syntax synchronisation object that we currently use. "
|
|
if self.sync_from_start():
|
|
return SyncFromStart()
|
|
else:
|
|
return self.syntax_sync
|
|
|
|
def find_closest_generator(i: int) -> Optional[LineGenerator]:
|
|
" Return a generator close to line 'i', or None if none was found. "
|
|
for generator, lineno in line_generators.items():
|
|
if lineno < i and i - lineno < self.REUSE_GENERATOR_MAX_DISTANCE:
|
|
return generator
|
|
return None
|
|
|
|
def create_line_generator(start_lineno: int, column: int = 0) -> LineGenerator:
|
|
"""
|
|
Create a generator that yields the lexed lines.
|
|
Each iteration it yields a (line_number, [(style_str, text), ...]) tuple.
|
|
"""
|
|
|
|
def get_text_fragments() -> Iterable[Tuple[str, str]]:
|
|
text = "\n".join(document.lines[start_lineno:])[column:]
|
|
|
|
# We call `get_text_fragments_unprocessed`, because `get_tokens` will
|
|
# still replace \r\n and \r by \n. (We don't want that,
|
|
# Pygments should return exactly the same amount of text, as we
|
|
# have given as input.)
|
|
for _, t, v in self.pygments_lexer.get_tokens_unprocessed(text):
|
|
# Turn Pygments `Token` object into prompt_toolkit style
|
|
# strings.
|
|
yield _token_cache[t], v
|
|
|
|
yield from enumerate(split_lines(list(get_text_fragments())), start_lineno)
|
|
|
|
def get_generator(i: int) -> LineGenerator:
|
|
"""
|
|
Find an already started generator that is close, or create a new one.
|
|
"""
|
|
# Find closest line generator.
|
|
generator = find_closest_generator(i)
|
|
if generator:
|
|
return generator
|
|
|
|
# No generator found. Determine starting point for the syntax
|
|
# synchronisation first.
|
|
|
|
# Go at least x lines back. (Make scrolling upwards more
|
|
# efficient.)
|
|
i = max(0, i - self.MIN_LINES_BACKWARDS)
|
|
|
|
if i == 0:
|
|
row = 0
|
|
column = 0
|
|
else:
|
|
row, column = get_syntax_sync().get_sync_start_position(document, i)
|
|
|
|
# Find generator close to this point, or otherwise create a new one.
|
|
generator = find_closest_generator(i)
|
|
if generator:
|
|
return generator
|
|
else:
|
|
generator = create_line_generator(row, column)
|
|
|
|
# If the column is not 0, ignore the first line. (Which is
|
|
# incomplete. This happens when the synchronisation algorithm tells
|
|
# us to start parsing in the middle of a line.)
|
|
if column:
|
|
next(generator)
|
|
row += 1
|
|
|
|
line_generators[generator] = row
|
|
return generator
|
|
|
|
def get_line(i: int) -> StyleAndTextTuples:
|
|
" Return the tokens for a given line number. "
|
|
try:
|
|
return cache[i]
|
|
except KeyError:
|
|
generator = get_generator(i)
|
|
|
|
# Exhaust the generator, until we find the requested line.
|
|
for num, line in generator:
|
|
cache[num] = line
|
|
if num == i:
|
|
line_generators[generator] = i
|
|
|
|
# Remove the next item from the cache.
|
|
# (It could happen that it's already there, because of
|
|
# another generator that started filling these lines,
|
|
# but we want to synchronise these lines with the
|
|
# current lexer's state.)
|
|
if num + 1 in cache:
|
|
del cache[num + 1]
|
|
|
|
return cache[num]
|
|
return []
|
|
|
|
return get_line
|