PHP Skeleton for Bison
This initiative extends the Bison parser generator to support PHP, enabling the creation of Abstract Syntax Tree (AST) parsers for languages like PHP, JSON, and SQL.
By integrating a PHP skeleton, developers can seamlessly generate parsers that integrate into PHP projects, enhancing parsing capabilities.
Bison is a parser generator.
You can extend it with PHP
Skeleton to generate PHP parsers.
For example, the PHP parser that can parse Nginx config:
php bin/parse.php nginx.conf
.
├── T_SERVER
├── T_SERVER_NAME { names: 'domain.tld, www.domain.tld' }
├── T_SERVER_ROOT { path: '/var/www/project/public' }
├── T_LOCATION { regexp: '' path: '/' }
│ └── T_TRY_FILES { paths: '$uri, /index.php$is_args$args' }
├── T_LOCATION { regexp: '' path: '/bundles' }
│ └── T_TRY_FILES { paths: '$uri, =404' }
├── T_LOCATION { regexp: '~' path: '^/index\.php(/|$)' }
│ ├── T_FAST_CGI_PATH { path: 'unix:/var/run/php/php-fpm.sock' }
│ ├── T_FAST_CGI_SPLIT_PATH_INFO { path: '^(.+\.php)(/.*)$' }
│ ├── T_INCLUDE { path: 'fastcgi_params' }
│ ├── T_FAST_CGI_PARAM { APP_ENV: 'prod' }
│ ├── T_FAST_CGI_PARAM { APP_SECRET: '<app-secret-id>' }
│ ├── T_FAST_CGI_PARAM { DATABASE_URL: '"mysql://db_user:db_pass@host:3306/db_name"' }
│ ├── T_FAST_CGI_PARAM { SCRIPT_FILENAME: '$realpath_root$fastcgi_script_name' }
│ ├── T_FAST_CGI_PARAM { DOCUMENT_ROOT: '$realpath_root' }
│ └── T_INTERNAL
├── T_LOCATION { regexp: '~' path: '\.php$' }
│ └── T_RETURN { code: '404' body: '' }
├── T_ERROR_LOG { path: '/var/log/nginx/project_error.log' }
└── T_ACCESS_LOG { path: '/var/log/nginx/project_access.log' }By default, Bison works with C, C++, D, and Java. But you can use it with PHP by adding a PHP skeleton.
How It Works
- grammar.y: a file where you define the syntax using BNF (Backus-Naur Form)
- skeleton.m4: a template file (written in M4) that helps create the parser
- parser.php: the parser file Bison generates, containing a Parser class
Bison reads your grammar.y file, processes it, and uses the skeleton.m4 file to generate the final parser file.
About Bison
- Read about how Bison works
- Read about how the PHP parser was made and compare it with other PHP parsers
- Read how to generate a C parser and use it with PHP FFI