> What is the purpose of this? Just static analysis? I'm not sure about the "Just" here. The opportunities for writing code transformation tools are abundant.

> What is the purpose of this? Just static analysis? I'm not sure about the "Just" here. The opportunities for writing code transformation tools are abundant. E.g. a PHP IDE that isn't written in PHP, a linting tool, a preprocessor for an embedded DSL. It isn't obvious to me that the tooling for a language like PHP need to be written in PHP. > Why Go? Go isn't a bad choice for writing parts of a compiler. The parser itself was, however, written with the parser generator goyacc rather than native Go code: https://github.com/z7zmey/php-parser/blob/master/php7/php7.y https://github.com/z7zmey/php-parser/blob/master/php7/php7.y Taking a goyacc file like this and porting it to another YACC is a lower effort than starting from scratch. In such a way, this project delivers not just "a PHP parser with xx% coverage in Go", but a shortcut to writing PHP parsers in any language with a decent YACC. One way this project is structured that I don't particularly like is that each node in the AST corresponds to a file. For a programming language with algebraic types (ML, Haskell), having the AST definition in a single file is quite typical. https://github.com/z7zmey/php-parser/tree/master/node/expr https://github.com/z7zmey/php-parser/tree/master/node/expr