[cheez]

They used Lisp to generate machine code. They didn't parse lisp at all. Imagine writing a library in your favorite language to do what they've done.

[reikonomusha]

They did parse it, albeit indirectly, by Racket’s reader. Co2 is a language, not a bunch of function calls, so it’s not quite the same as building a library in your favorite language. The article even gives examples of new syntax they produced.

Parsing Lisp in Lisp is so easy because it’s free.

[cheez]

https://github.com/dustmop/co2/blob/master/compile.scm#L3689

Indeed, it's almost trivial.

[lispm]

you just need to implement read-syntax ...

[cheez]

I wasn't being sarcastic, it was very simple the way they've done it. https://docs.racket-lang.org/reference/Reading.html#%28def._...

[lispm]

I'm saying that there is a larger machinery behind it. It just looks simple.

[cheez]

Well ok but then technically a hello world is complex for the same reasons

[lispm]

> Parsing Lisp in Lisp is so easy because it’s free.

You just have to implement an s-expression reader.

Plus an interpreter, compiler or a code walker, which can actually parse the Lisp code.

[colejohnson66]

> Parsing Lisp in Lisp is so easy because it’s free.

Are there any other languages that have this feature? I.E. where the data and the code are the same syntax?

[guicho271828]

Well, if there is new such language then it would be eventually called a lisp dialect.

[kayamon]

Rebol springs to mind.