- Implemented new 64-bit instruction encoding scheme that is simpler and more efficient. String data is no longer embedded in the instruction stream, ensuring constant instruction length of 8 bytes.
- Merged
lug::program_encoder
andlug::rule_encoder
into thelug::encoder
base class after overhauling how choice/jump offsets are calculated, significantly reducing binary size bloat. - Extracted common base class of
lug::basic_parser
intolug::parser_base
to reduce template bloat. - Reduced template bloat for parser directives (improving compiler error messages) and optimized nested directives.
- Merged parser stack frames together into a single stack using
std::variant
. - Removed use of
goto
in parsing machine main loop. - Changed grammar program generation to force inline the start rule.
- Implemented tail call optimization.
- Added list repetition operator
e1 >> e2
to the DSL that is shorthand fore1 > *(e2 > e1)
. - Added support for parsing characters and character literals where applicable without explicitly needing to wrap them with
chr()
or_cx
. - Symbols now respects
caseless
mode, allowing for case-insensitive matching against symbol definitions. - Allow for use of variables of all types in attribute bindings and removed the
lug::variable
template class that was used previously. Variable state is automatically saved and restored across rule boundaries. - Allow for capturing text to a
lug::syntax
object or any string-like object that is convertible fromstd::string_view
, and renamedsyntax::capture
tosyntax::str
in order to matchstd::sub_match::str
. - Added
lug::source_options::interactive
flag that ignoreseoi
tokens for TTY input sources. - Rewrote the expression function objects/lambdas as expression template classes. Allows for multiple passes over the expression tree as well as top-down and bottom-up traversal, which was needed when implementing attribute state tracking. This will also allow for additional optimizations to be implemented in the future.
- Renamed
syntactic_capture
tosemantic_capture_action
to reflect that it is executed during the semantic action evaluation phase. - Make all variations of callables that return a non-void value that can be type-erased by
semantic_action
andsemantic_capture_action
push their result onto the attribute result stack. - Removed
semantic_response
from the public API as it was only used internally inside of the parser. - Attempting to bind a variable to a nonexistent value from the attribute result stack now throws an
attribute_stack_error
. implicit_space_rule
no longer causes a compiler warning with Clang, uses RAII to push/pop the thread-local white space rule for grammars.- Moved
call_depth()
,prune_depth()
andescape()
functions into thelug::environment
class since they are used exclusively during semantic action phase. - Moved line/column tracking and current match/subject string views to
lug::environment
class, fully removing the environment's dependency onlug::parser
. - Turned
lug::parser
into an alias of a newlug::basic_parser
template class parameterized with an input source strategy. This allows for parsing and capturing of text without making a copy of the input. - Placed all DSL operator overloads inside of an inline namespace
operators
withinlug::language
. This allows only the operators to be imported into the current scope if desired. - Enabled
-Wconversion
and-Wshadow
warnings for Clang and GCC and fixed warnings. - Full clang-tidy pass on all of the library headers and fixed all warnings.
- Added CMake build support and removed old MSVS solution and vcxproj files.
- Handle situation where compilation with RTTI is disabled.
- Implemented new support for context-sensitive grammars with symbol tables and parsing conditions based on the PEG extensions described in the paper "A Declarative Extension of Parsing Expression Grammars for Recognizing Most Programming Languages" by Tetsuro Matsumura and Kimio Kuramitsu (2015).
- Added an XML Standard 1.0 matcher sample program demonstrating use of symbol tables.
- Finished the BASIC language interpreter sample program, which is now feature complete, using parsing conditions.
- Updated Unicode support to version 15.1.0 and automated Unicode table generation via Makefile build.
- Various compilation error fixes for modern C++17 compilers (Clang, GCC, MSVC++), as well as fixing compilation errors when compiling in C++20 and C++23 modes. Includes fixes merged from @trombonehero.
- Code cleanup pass, with numerous improvements applying
const
,constexpr
,[[nodiscard]]
,noexcept
and fixing new compilation warnings enabled with-Wextra
,-Wextra-semi
,-Wsign-conversion
and-Wsuggest-override
on Clang and GCC. - Initial clang-tidy support with .clang-tidy file and lint Makefile target.
- Migrated from Travis CI to Github Actions CI.
- Initial Release.