Lemon (parser generator)
 | This article needs more citations. (December 2011) |
| Lemon | |
|---|---|
| Developer | D. Richard Hipp |
| Written in | C |
| Operating system | Cross-platform |
| Type | Parser generator |
| License | Public domain |
| Website | www |
Lemon is a parser generator, maintained as part of the SQLite project, that generates a look-ahead LR parser (LALR parser) in the programming language C from an input context-free grammar. The generator is quite simple, implemented in one C source file with another file used as a template for output. Lexical analysis is performed externally. [1]
Lemon is similar to the programs Bison and Yacc, but is incompatible with both. The grammar input format is different, to help prevent common coding errors. Other distinctive features include a reentrant, thread-safe output parser, and the concept of non-terminal destructors that try to make it easier to avoid memory leaks. [2]
SQLite uses Lemon with a hand-coded tokenizer to parse SQL strings.
Lemon, together with re2c and a re2c wrapper named Perplex, are used[3][4][5] in BRL-CAD as platform-agnostic and easily compilable alternatives to Flex and Bison. This combination is also used with STEPcode.[6]
OpenFOAM expression evaluation[7] uses a combination of ragel and a version of lemon that has been minimally modified[8] to ease C++ integration without affecting C integration.[9] The parser grammars are augmented with m4 macros.
Notes
[edit source]- ↑ "The Lemon LALR(1) Parser Generator". SQLite. SQLite. 2022-04-18. Retrieved 2026-07-27.
- ↑ "The Lemon Parser Generator". SQLite. SQLite. 2025-11-18. Retrieved 2026-07-27.
- ↑ Brlcad; Carlmoore; Starseeker (2017-11-30). "BRL-CAD: The Lemon Parser Generator". SourceForge. Slashdot Media. Retrieved 2019-09-21.
- ↑ Bumbulis, Peter (2011-08-23). "Read Me". SourceForge. Slashdot Media. Retrieved 2019-09-21.
- ↑ Boerger, Marcus (2014-06-24). "Read Me". SourceForge. Slashdot Media. Retrieved 2019-09-21.
- ↑ "Read Me". STEPcode. GitHub. 2015. Archived from the original on 2018-04-10. Retrieved 2019-09-21.
- ↑ "New expressions syntax". OpenFOAM. OpenCFD. 2019-12-23. Retrieved 2020-01-13.
- ↑ "wmake sources". OpenFOAM. OpenCFD. 2019-09-27. Retrieved 2020-01-13.
- ↑ "README". OpenFOAM. OpenCFD. 2019-09-27. Retrieved 2020-01-13.
References
[edit source]- "The Lemon Parser Generator". Retrieved 2020-05-21.
- "Architecture of SQLite". 2008-11-01. Retrieved 2020-05-21.