## Unreleased

### New Features

- Add `p_parse_inner_XXX()` APIs that accept a caller-provided set of follow
  tokens. These behave the same as `p_parse_XXX()` by parsing starting at the
  given start rule, but instead of expecting the rest of the input to match
  the start rule they allow specifying a set of tokens that may follow the
  start rule.
- Add `p_set_position()` API to set the current text position stored in the
  context. Useful for setting the initial text position to something other
  than `(1, 1)` for a nested parse operation.
- Add `p_input_index()` API to get the current input text byte offset.
- Add `p_set_input_index()` API to set the current input text byte offset.
  Useful together with `p_set_position()` to rewind the input part-way through
  a parse in order to re-read an earlier section of the input.

## v4.7.0

### New Features

- Support parser rule user code blocks in tree generation mode.

### Fixes

- propane.vim: do not highlight rule components as propane keywords

## v4.6.0

### New Features

- Add lexer user code API to access matched input text positions
- Track rule component text positions and add parser user code API to access

### Fixes

- Fixed a few user guide and source comments related to text input positions

## v4.5.0

### New Features

- Add `noline` grammar statement to skip emitting `#line` directives
- Attempt to autodetect target language (D/C++) in extra/vim/syntax/propane.vim

### Fixes

- Fix #line reset directives
- Update keyword list in extra/vim/syntax/propane.vim
- Fix propane.vim keyword detection

## v4.4.0

### New Features

- Add p_value_get() / p_value_get_XXX() accessors

## v4.3.0

### New Features

- Use #line for user code blocks to report input grammar position for errors.

## v4.2.0

### New Features

- Add support for a custom lex function.

## v4.1.0

### New Features

- Add `p_context_delete()` and `p_tree_delete()` for D targets.

## v4.0.0

### New Features

- Add `context_user_fields` statement to allow custom context user fields.
- Add `token_user_fields` statement to allow custom token user fields.
- Add `on_token_node` statement to allow custom code when constructing token nodes.
- Add `free_token_node` statement to allow custom code when freeing token nodes.
- Add `p_context_delete()`.
- Allow `drop` patterns to execute lexer user code blocks.

### Breaking Changes

- Replace `p_context_init()` with `p_context_new()` and `p_context_delete()`.
- Renamed `p_free_tree()` to `p_tree_delete()`.
- The `free_token_node` statement now takes a user code block instead of a
  function name parameter.

## v3.0.0

### New Features

- Add support for multiple starting rules (#38)
- Add `p_free_tree()` functions to reclaim generated tree memory
- Add `free_token_node` grammar statement to reclaim user-allocated memory stored in a Token tree node `pvalue` field
- Add valgrind memory leak tests to unit tests
- Fix build issues for C++ to officially support C++ target output

### Improvements

- Document `p_lex()` and `p_token_info_t` in user guide (#37)

### Breaking Changes

- Rename AST generation mode to tree generation mode (see [UPGRADING.md](UPGRADING.md))

## v2.3.0

### New Features

- Add \D, \S, \w, \W special character classes

### Improvements

- Include line numbers for pattern errors
- Improve performance in a few places
- Parallelize parser table generation on Linux hosts
- Add github workflow to run unit tests

### Fixes

- Fix a couple clang warnings for C backend
- Fix C backend not fully initializing pvalues when multiple ptypes are used with different sizes.
- Fix some user guide examples

## v2.2.1

### Fixes

- Fix GC issue for D backend when AST is enabled (#36)

## v2.2.0

### Improvements

- Allow multiple lexer modes to be specified for a lexer pattern (#35)
- Document p_decode_code_point() API function (#34)

## v2.1.1

### Fixes

- Field aliases for AST node fields could alias incorrect field when multiple rule alternatives present for one rule set (#33)

## v2.1.0

### Improvements

- Report rule name and line number for conflicting AST node field positions errors (#32)

## v2.0.0

### Improvements

- Log conflicting rules on reduce/reduce conflict (#31)
- Use 1-based row and column values for position values (#30)

### Fixes

- Fix named optional rules (#29)

### Upgrading

- Adjust all uses of p_position_t row and col values to expect 1-based instead
of 0-based values.

## v1.5.1

### Improvements

- Improve performance (#28)

## v1.5.0

### New Features

- Track start and end text positions for tokens and rules in AST node structures (#27)
- Add warnings for shift/reduce conflicts to log file (#25)
- Add -w command line switch to treat warnings as errors and output to stderr (#26)
- Add rule field aliases (#24)

### Improvements

- Show line numbers of rules on conflict (#23)

## v1.4.0

### New Features

- Allow user to specify AST node name prefix or suffix
- Allow specifying the start rule name
- Allow rule terms to be marked as optional

### Improvements

- Give a better error message when a referenced ptype has not been declared

## v1.3.0

### New Features

- Add AST generation (#22)

## v1.2.0

### New Features

- Allow one line user code blocks (#21)
- Add backslash escape codes (#19)
- Add API to access unexpected token found (#18)
- Add token_names API (#17)
- Add D example to user guide for p_context_init() (#16)
- Allow user termination from lexer code blocks (#15)

### Fixes

- Fix generator hang when state transition cycle is present (#20)

## v1.1.0

### New Features

- Add user parser terminations (#13)
- Document generated parser API in user guide (#14)

## v1.0.0

- Initial release