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Comment by capableweb | Hacker News Reader

> I too had an ephiphany when I realized Elixir was actually a Lisp.

Is it actually? Last time I looked at Elixir (granted, that was a while ago), the syntax for writing macros was different than the syntax for writing ordinary code, so it fails even at a simple thing like that, it doesn't seem to support homogeneous meta-programming at all.

But again, I feel like I might be wrong here and I'm happy to be proven wrong.

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Ya, it's not actually a lisp. I can't find the source but José has stated part of the idea was to give you lisp-like metaprogramming with a non-lisp syntax (sorry, José, if I have mis-quoted).

Even the regular syntax is sort of lispish, though, if you remove the syntactic sugar. It's all macros and datastructres.

    defmodule Foo do
      def bar do
        "baz"
      end
    end

is really:

    defmodule Foo, do: (def bar, do: "baz")

...which is lispish if you squint the right way.

A bit pedantic I guess, but that still uses some syntactic sugar (optional brackets and keyword syntax). Removing all syntactic sugar would look like this:

    defmodule(Foo, [{:do, def(:bar, [{:do, "baz"}])}])

Even aliases (like Foo) are also a kind of syntactic sugar for a specific type of atom (Foo is actually the atom :"Elixir.Foo")

Ha, ya I meant remove the `do` sugar.

That’s just syntax sugar. Even the original Lisp was supposed to have sugar on top of S-expressions, although that never really happened.

https://en.m.wikipedia.org/wiki/M-expression

I think Mathematica has had a slight variant since 1988 (i've been using it since then, but never M-expressions, but they look awfully similar).

It's listed under the "Implementations" section of that wiki article.

You can write macros (as well as functions, actually) that accept AST and emit transformed AST back. It has quote and unquote. Turns out that it doesn't need homoiconicity to accomplish Lisp-level macro capability, which means it has all the power of a Lisp but with actual syntax (which is, like it or not, more appealing to many people) in a language with deep pattern-matching and completely immutable data guarantees.

What is the actual failure? The macros are written with and by processing the built-in data structures.

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