lark-parser/lark

Add support for the `a` and `L` regex flags

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#1,527 创建于 2025年4月21日

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 (5 评论) (0 反应) (0 负责人)Python (4,275 star) (384 fork)batch import
enhancementgood first issue

描述

Lark currently only supports the flags imslux, however Python supports two additional ones, which perhaps some people will find useful.

While users can still use inline flags, it might be nice for Lark to support it as part of the syntax, and it should be pretty easy.

https://docs.python.org/3/library/re.html#flags

贡献者指南

技术栈
python
领域
backendtooling
议题类型
feature
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
2
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
1-3 hours
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
fresh
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
Understanding of Python regex flagsFamiliarity with Lark's lexer implementation
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
70
研究方向
The issue is to add support for `a` (ASCII) and `L` (locale) flags in Lark's regex syntax. Currently Lark supports flags `imslux`. The implementation likely involves modifying the lexer or grammar to recognize these new flags. Look at how existing flags are parsed and applied, potentially in files like `lark/lexer.py` or `lark/grammar.py`. The maintainers have not yet responded, so no specific guidance is available. A good starting point is to examine the current flag handling code and add the two new flags in a similar manner.