Release 2025.05.0

[foonathan]

Potential breaking changes

• scanner-common::capture_token was renamed to scanner-common::capture, and old scanner-common::capture removed.
  Previously, capture_token was a linker error anyway, but if you're calling scanner-common::capture it will no longer work for arbitrary rules and instead only like dsl::capture.
• lexy::parse_as_tree will add a position token to production nodes that would otherwise be empty.
  That way, no production node will be empty, unless the builder API is used directly.
• Change lexy::dsl::try_() error recovery behavior:
  It will now skip whitespace after the (optional) error recovery rule.
• Deprecate the lexy::parse_tree::builder::finish() overload that does not take a remaining_input.
• The typo lexy::code_point::spaing_mark was fixed to spacing_mark.

New Features

• Experimental: Add lexy::parse_tree_input and lexy::dsl::tnode/lexy::dsl::pnode to support multi-pass parsing.
• Add lexy::dsl::byte.if_/set/range/ascii methods to match specific bytes.
• Add an overload of fatal_error() on scanners that allows construction of type-erased generic errors (Allow scanners to construct generic errors #134).
• Add lexy::buffer::release() and lexy::buffer::adopt() to deconstruct a buffer into its components and re-assemble it later.
• Add lexy::parse_tree::node::position() and ::covering_lexeme().
• Add default argument to lexy::dsl::flag().
• Add lexy::callback_with_state.
• Pass the parse state to the tag of lexy::dsl::op if required (Construct operator tags with state #172) and to lexy::dsl::error (lexy::dsl::error(rule) cannot compile if the rule has a scanner that needs a parse state #211).
• Enable CMake install rule for subdirectory builds (Install only defined if lexy is top level project #205).

Bug fixes

• Add missing constexpr to container callbacks and lexy::as_string.
• Fix infinite loop in dsl::delimited when dealing with invalid code points (dsl::delimited loops forever when an invalid codepoint is encountered #173).
• Fix swallowed errors from case-folding rules (case_folding discards errors in validate and parse actions #149).
• Fix lexy::production_name for productions in an anonymous namespace.
• Fix bugs in dsl::scan (Surprising debug behavior when re-using lexy::scan_result<> #133, Assertion failure on scan rule failure #135, Problems using the scan action with parser state #142, Statis assertion failure regression on scanner.branch #154, lexyd::_detect_scan_state cannot detect state for non-defaulted parsed values  #209).
• Fix bug with the position passed to the tag constructor of lexy::dsl::op (location tracking for operators #170).
• Fix bug where lexy_ext::report_error unconditionally wrote to stderr, ignoring the output iterator.
• Fix bug with missing lexy::error_context::position in lexy::parse_as_tree (SIGSEGV on Iterator lexy::_detail::min_range_end #184).
• Fix static_assert in lexy::parse_tree (parse_as_tree static assertion fails in Debug configuration on MSVC #190).
• Fix bugs in lexy::input_location::operator< (Fix erroneous member access for input_location::operator< #228).
• Fix bugs in examples (Fix IP address printing: 4 hex digits per piece #183)
• Add missing && in lexy::bind_sink (Add missing && to _bound_sink #221).
• Workaround compiler bugs and improve documentation (Fix misplaced static_assert #128, Work around MSVC Class template argument deduction confusion #129, Fix typo in parse and validate documentation #146, Fix static assertion failures produced by MSVC #181, <bit> produces warning when building with C++17 #197, Documentation needs back links #216, Fix CMake Deprecation Warning #227).

New Contributors

• @jgopel made their first contribution in Fix misplaced static_assert #128
• @NelsonEloi made their first contribution in Work around MSVC Class template argument deduction confusion #129
• @nickelpro made their first contribution in Allow scanners to construct generic errors #134
• @jan-kelemen made their first contribution in Fix typo in parse and validate documentation #146
• @shohirose made their first contribution in Fix static assertion failures produced by MSVC #181
• @MarcusVoelker made their first contribution in Adding case for void state to production_value_callback #182
• @klao made their first contribution in Fix IP address printing: 4 hex digits per piece #183
• @stotiks made their first contribution in <bit> produces warning when building with C++17 #197
• @TheServer201 made their first contribution in Fix CMake Deprecation Warning #227
• @Spartan322 made their first contribution in Fix erroneous member access for input_location::operator< #228

Full Changelog: v2022.12.1...v2025.05.0

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This discussion was created from the release Release 2025.05.0.