Right now there is a divide among programmers. One one side you have people like the author who crave the power of code-as-data more than they care about nice

Right now there is a divide among programmers. One one side you have people like the author who crave the power of code-as-data more than they care about nice syntax and therefore love Lisp. On the other side you have people who like more conventional syntax more than they care about code-as-data and therefore don't love Lisp. Neither side can understand the other: one side says "why do you resist ultimate power?" and the other side says "how can you possibly think that your code is readable?" My belief (and what I am starting to consider my life's work) is that the gap can be bridged. Lisp's power comes from treating code as data. But all code becomes data eventually; turning code into data is exactly what parsers do, and every language has a parser. The author says "it's about read," but "read" (in his example) is just a parser. The author asks "How would you do that in Python?" The answer is that it would be something like this: import ast class MyTransformer(ast.NodeTransformer): pass # Implement transformation logic here. node = MyTransformer().visit(ast.parse("x = 1")) print ast.dump(node) This works alright, but what I'm after is a more universal solution. With syntax trees there's a lot of support functionality you frequently want: a way to specify the schema of the tree, convenient serialization/deserialization, and ideally a solution that is not specific to any one programming language. My answer to this question might surprise some people, but after spending a lot of time thinking about this problem, I'm quite convinced of it. The answer is Protocol Buffers. It's true that Protocol Buffers were originally designed for network messaging, but they turn out to be an incredibly solid foundation on which to build general-purpose solutions for specifying and manipulating trees of strongly-typed data without being tied to any one programing language. Just look at a system like http://scottmcpeak.com/elkhound/sources/ast/index.html http://scottmcpeak.com/elkhound/sources/ast/index.html that was specifically designed to store AST's and look how similar it is to .proto files. (As an aside, programmers have spent the last 15 years or so attempting to use XML in this role of "generic language-independent tree structured serialization format," but it wasn't the right fit because most data is not markup. Protocol Buffers can deliver on everything people wanted XML to be). Why should manipulating syntax trees require us to write in syntax trees? The answer is that it shouldn't, but this is non-obvious because of how inconvenient parsers currently are to use. One of my life's goals is to help change that. If you find this intriguing, please feel free to follow: https://github.com/haberman/upb/wiki https://github.com/haberman/gazelle