| """ |
| Base classes for prompt_toolkit lexers. |
| """ |
| from __future__ import annotations |
|
|
| from abc import ABCMeta, abstractmethod |
| from typing import Callable, Hashable |
|
|
| from prompt_toolkit.document import Document |
| from prompt_toolkit.formatted_text.base import StyleAndTextTuples |
|
|
| __all__ = [ |
| "Lexer", |
| "SimpleLexer", |
| "DynamicLexer", |
| ] |
|
|
|
|
| class Lexer(metaclass=ABCMeta): |
| """ |
| Base class for all lexers. |
| """ |
|
|
| @abstractmethod |
| def lex_document(self, document: Document) -> Callable[[int], StyleAndTextTuples]: |
| """ |
| Takes a :class:`~prompt_toolkit.document.Document` and returns a |
| callable that takes a line number and returns a list of |
| ``(style_str, text)`` tuples for that line. |
| |
| XXX: Note that in the past, this was supposed to return a list |
| of ``(Token, text)`` tuples, just like a Pygments lexer. |
| """ |
|
|
| def invalidation_hash(self) -> Hashable: |
| """ |
| When this changes, `lex_document` could give a different output. |
| (Only used for `DynamicLexer`.) |
| """ |
| return id(self) |
|
|
|
|
| class SimpleLexer(Lexer): |
| """ |
| Lexer that doesn't do any tokenizing and returns the whole input as one |
| token. |
| |
| :param style: The style string for this lexer. |
| """ |
|
|
| def __init__(self, style: str = "") -> None: |
| self.style = style |
|
|
| def lex_document(self, document: Document) -> Callable[[int], StyleAndTextTuples]: |
| lines = document.lines |
|
|
| def get_line(lineno: int) -> StyleAndTextTuples: |
| "Return the tokens for the given line." |
| try: |
| return [(self.style, lines[lineno])] |
| except IndexError: |
| return [] |
|
|
| return get_line |
|
|
|
|
| class DynamicLexer(Lexer): |
| """ |
| Lexer class that can dynamically returns any Lexer. |
| |
| :param get_lexer: Callable that returns a :class:`.Lexer` instance. |
| """ |
|
|
| def __init__(self, get_lexer: Callable[[], Lexer | None]) -> None: |
| self.get_lexer = get_lexer |
| self._dummy = SimpleLexer() |
|
|
| def lex_document(self, document: Document) -> Callable[[int], StyleAndTextTuples]: |
| lexer = self.get_lexer() or self._dummy |
| return lexer.lex_document(document) |
|
|
| def invalidation_hash(self) -> Hashable: |
| lexer = self.get_lexer() or self._dummy |
| return id(lexer) |
|
|
