# 0.2.0

URL: /releases/0.2.0/
Section: releases
Tags: release, 0.2.0
Date: 2026-02-13

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0.2.0 Released: 2026-02-13 AST tooling and incremental parsing for editor integrations and incremental builds. Highlights Incremental re-parsing — O(change) updates instead of O(document) full re-parse AST differ — Structural diff between two Documents for change detection Visitor + transform — Typed traversal and immutable rewriting Serialization — JSON round-trip for caching and wire transfer Thread-safety fix — get_headings now safe under free-threading Features Incremental Parsing from patitas import parse_incremental, parse prev = parse("# Hello\nWorld") # User edits "World" → "Updated" (char 7–12) new_doc = parse_incremental( "# Hello\nUpdated", prev, edit_start=7, edit_end=12, new_length=7 ) Re-parses only blocks overlapping the edit. Unaffected blocks are reused. AST Diffing from patitas import parse, diff_documents old_doc = parse("# Hello\nWorld") new_doc = parse("# Hello\nUpdated world") for change in diff_documents(old_doc, new_doc): print(f"{change.kind} at {change.path}") Use for incremental builds, live preview, or change detection. Visitor and Transform from patitas import parse, BaseVisitor, transform, Heading class HeadingCollector(BaseVisitor[None]): def __init__(self) -> None: self.headings: list[Heading] = [] def visit_heading(self, node: Heading) -> None: self.headings.append(node) doc = parse(source) collector = HeadingCollector() collector.visit(doc) transform(doc, fn) rewrites the AST immutably (bottom-up). Serialization from patitas import parse, to_dict, from_dict, to_json, from_json doc = parse("# Hello **World**") # Dict format (in-memory caching, e.g. Bengal incremental builds) data = to_dict(doc) restored = from_dict(data) # JSON format (persistence, wire transfer) json_str = to_json(doc) restored = from_json(json_str) Deterministic output for cache-key stability. See Serialization. Installation pip install patitas>=0.2.0 pip install patitas[syntax] # Syntax highlighting via Rosettes Breaking Changes None — all additions are backwards compatible. Documentation Serialization — Cache and transfer AST AST Processing — Visitor and transform AST Diffing — Structural diff usage

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