Lark v1.3.1 Release Notes
Release Date: 2025-10-27 // 8 months ago-
What's Changed
- 🛠 Bugfix: Restore support for custom input, alongside text and TextSlice by @erezsh in #1562
- 🏗 Keep sdist in sync with git (include all files in source build, including docs, tests and examples) by @chanicpanic in #1561
Full Changelog : 1.3.0...1.3.1
Previous changes from v1.3.0
-
🆕 New features
- ✅ Lark can now parse in sections of strings, using
TextSlice, as a faster alternative to creating a "copy-slice" withs[i:j]. Learn more - ➕ Added support to
matchon Tree instances - When serializing a Lark instance, added the option to include the grammar object (before compilation).
- ➕ Added convenience method
Tree.find_token()
🛠 Bugfixes
- 🛠 Bugfix of an edge case in Earley related to representation of ambiguity.
- 🛠 Bugfixes in the standalone parser related to imports
- 🛠 Bugfix in indenter - now dedents always contain line information
- 🛠 Various small bugfixes (see PR list below)
Full list of PRs
- 📄 Docs: Rephrase v_args() documentation to underline it only applies to Transformer classes by @skepppy in #1458
- 🔨 Tiny refactor for PR #1451 by @erezsh in #1459
- 📜 Earley: share nodes created by the scanner with the completer by @chanicpanic in #1451
- 👍 Better error in Lark.parse when using on_error when parser!=lalr (issue #1311) by @erezsh in #1460
- Fix
Symbol. __eq__to return false when comparing with None by @weaversam8 in #1481 - 📚 Mention internal/external transformers in the documentation by @odanoburu in #1486
- ➕ Add Tree.find_token() method by @makukha in #1467
- Type
Terminal. __init__by @Liam-DeVoe in #1503 - ➕ Add guidance on handling comments in languages with significant indentation by @nchammas in #1502
- 📜 [docs] Small fix for PR 1507 by @erezsh in #1508
- ➕ Add note on binding power of numeric quantifiers by @414owen in #1507
- 📜 Wrap functools.partial in staticmethod() to add compatibility with Python 3.14 by @hrnciar in #1483
- 🛠 Fix generic type of Transformer_InPlaceRecursive by @lbhm in #1518
- ➕ Added TextSlice; Lark can now parse/lex a text-slice by @erezsh in #1452
- 👌 Support match on tree by @colmmurphyxyz in #1521
- 📄 Docs: Updated link of DSL article to a new version by @erezsh in #1529
- 👍 better error messages for shift/reduct conflicts by @skogsbaer in #1531
- 📜 Serialize Lark.grammar (fixes issue #1472) by @NasalDaemon in #1506
- 🛠 Fixes for PR #1506, which adds the option to cache the grammar definition by @erezsh in #1540
- 🛠 Bugfix in indenter - now always creating dedents with line information by @erezsh in #1547
- 🛠 Bugfix: issue when unpickling in the standalone parser, due to lingering Token instances by @erezsh in #1553
- 📜 Include missing import in standalone parser by @pdeibert in #1541
- 🔖 Version bump (1.3.0) by @erezsh in #1554
🆕 New Contributors
- 📜 @skepppy made their first contribution in #1458
- 📜 @weaversam8 made their first contribution in #1481
- 📜 @odanoburu made their first contribution in #1486
- 📜 @makukha made their first contribution in #1467
- 📜 @Liam-DeVoe made their first contribution in #1503
- 📜 @414owen made their first contribution in #1507
- 📜 @hrnciar made their first contribution in #1483
- 📜 @lbhm made their first contribution in #1518
- 📜 @colmmurphyxyz made their first contribution in #1521
- 📜 @skogsbaer made their first contribution in #1531
- 📜 @NasalDaemon made their first contribution in #1506
- 📜 @pdeibert made their first contribution in #1541
Full Changelog : 1.2.2...1.3.0
- ✅ Lark can now parse in sections of strings, using