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The char8_t overloads were passing *path instead of path, which would dereference a null pointer when path=nullptr (the default). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Test file and grammar definitions for left recursion support. Tests are currently non-compiling (parser constructor changes needed). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Add Definition::is_left_recursive flag - Add enable_left_recursion parameter (default: true) to parser/ParserGenerator - When enabled, mark LR rules instead of reporting errors - Fix operator bool() const for parser class - Update test2.cc existing LR tests to explicitly disable LR support - Add test_left_recursive.cc to CMakeLists Note: LR grammars are now accepted but parsing them will hang until Phase 2 (seed growing) is implemented. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add seed growing algorithm for left-recursive rules: - LRMemo in Context for mutable memoization during growth - Cycle detection via lr_refs_hit with self-insertion for transitive cycles - lr_active_seeds to protect outer growers from inner growers' memo erasure - Shared do_parse lambda eliminates duplication between LR and non-LR paths - Extract write_packrat_cache/clear_packrat_cache helpers from Context Handles direct, indirect, mutual, and cascading left recursion. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Add ComputeCanBeEmpty visitor with fixed-point iteration to determine which rules can match the empty string - Fix DetectLeftRecursion::visit(Reference) to use can_be_empty: when a referenced rule can match empty, don't mark the sequence position as done, allowing detection of hidden LR through nullable prefixes - Add Definition::can_be_empty flag Fixes: A <- B C A / 'a' with B <- C?, C <- 'c'? was not detected as left-recursive when C was visited twice (once through B, once directly), causing infinite recursion at parse time. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Fix typo: LeftRecursionText -> LeftRecursionTest
- Enable 12 epsilon-hidden LR tests (previously DISABLED), with corrected
expectations (EXPECT_TRUE for parser compilation with LR enabled)
- Consolidate 20 DISABLED tests down to 12 (remove redundant variants)
- Consolidate 3 packrat tests into 1 (PackratWithLeftRecursion)
- Delete Phase1_DefIdMapping (tested nothing LR-specific)
- Remove 4 non-LR regression tests redundant with existing test suite
(JSON, CDeclarations, DeclarationSyntax, PythonExpressions)
- Fix indirect LR TODO: parser.parse("dbacba") now works
- Add LeftAssociativity test (1-2-3=-4, 8/4/2=1)
- Extract setup_arithmetic_actions helper to reduce duplication
- Keep 2 non-LR regression tests (right-recursive expr, TypeScript types)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- DetectLeftRecursion now traverses macro parameter references via
macro_args_stack_, detecting LR through parameterized rules (e.g.
Expr <- Apply(Expr, '+', Number) / Number). Nested macros are
resolved by walking up the args stack with resolve_macro_arg().
- Runtime re-entry protection prevents stack overflow from any
undetected left recursion:
- Packrat mode: pre-register cache entry as failure before parsing,
so re-entry at the same position returns failure (zero overhead).
- Non-packrat mode: use lr_memo as temporary re-entry guard.
- Update README.md with left recursion documentation and feature list.
- Update benchmark/README.md with latest results (3.6x YACC ratio).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The `parser("...", {}, false)` calls in left recursion tests were
ambiguous on MSVC because `{}` could match Rules, string_view, or
size_t. Switch to explicit `load_grammar()` with `std::string_view{}`.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Replace the enable_left_recursion parameter on constructors and load_grammar with an enable_left_recursion() method, matching the existing enable_packrat_parsing() pattern. This eliminates MSVC overload ambiguity and simplifies the API. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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