Issues

Issues

• TextSlice accepts an end past the text

  lark-parser/lark#1659 · opened on Oct 1, 2026

• Zero-width regex terminal rejected even when the surrounding rule can never match zero characters

  lark-parser/lark#1640 · opened on Aug 16, 2026
  1

• Invalid Tree structure and anti-patterns in lark/tests/test_pattern_matching.py

  lark-parser/lark#1608 · opened on Jun 13, 2026
  1

• TextSlice implementation breaks codebases based on 1.2.2

  lark-parser/lark#1599 · opened on Jun 1, 2026
  5

• Optional closing tag causes runtime error: Earley generates multiple start symbol items

  lark-parser/lark#1587 · opened on Apr 9, 2026
  1

• Infinite loop in lalr and cyk

  lark-parser/lark#1585 · opened on Mar 24, 2026
  3

• Export and document lark.tools.standalone.gen_standalone

  lark-parser/lark#1583 · opened on Mar 23, 2026
  2

• __default_token__ and __default__ not called for Lark(transformer=transformer).

  lark-parser/lark#1582 · opened on Mar 23, 2026
  7

• contextual lexer accept set seems wrong

  lark-parser/lark#1581 · opened on Mar 23, 2026

• The version on https://pypi.org/project/lark-parser/ is 0.12.0

  lark-parser/lark#1574 · opened on Feb 13, 2026
  2

• python.lark failed to pare special forms of with_stmt

  lark-parser/lark#1570 · opened on Dec 7, 2025
  2

• Allow rules in templates

  lark-parser/lark#1566 · opened on Oct 31, 2025
  2

• Improve memory usage in the contextual lexer ?

  lark-parser/lark#1539 · opened on Jul 5, 2025

• Misaligned error location when input text contain full-width characters

  lark-parser/lark#1530 · opened on Apr 24, 2025
  2

• Add support for the a and L regex flags

  Feature

  lark-parser/lark#1527 · opened on Apr 21, 2025
  6

• Parsing bytestrings and token values

  lark-parser/lark#1526 · opened on Apr 18, 2025
  3

• Lark needs a favicon

  lark-parser/lark#1510 · opened on Jan 24, 2025
  4

• Move documentation to bootstrap 5

  lark-parser/lark#1494 · opened on Nov 30, 2024
  3

• Difference in LALR Grammar Parsing

  lark-parser/lark#1489 · opened on Nov 16, 2024

• Ignored terminal used in the grammar is expected with Earley but not with LALR

  lark-parser/lark#1473 · opened on Sep 26, 2024
  3

• Syntactic sugar: Tree.has_data()

  lark-parser/lark#1465 · opened on Sep 11, 2024
  5

• Lark resulting LALR -nor- Earley parser will pick out the longest match of say "a + b + c + ... + d" example input. Bug (?)

  lark-parser/lark#1463 · opened on Sep 4, 2024
  1

• Generate counter-examples for conflicts in LALR parsing

  lark-parser/lark#1449 · opened on Aug 16, 2024
  3

• Terminal collision when importing the same terminal from different grammars

  lark-parser/lark#1448 · opened on Aug 15, 2024

• tests/test_cache.py and Python >= 3.12: SyntaxWarning: invalid escape sequence '\w'

  lark-parser/lark#1445 · opened on Aug 13, 2024