Finish blaze lisp article

content/articles/blaze-lisp.md

@@ -3,7 +3,7 @@ title: "blaze lisp"
 description: "An implementation of the MAL (Make a Lisp) project."
 navigation: false
 date: "2023-03-18"
-img: "/img/.png"
+img: "/img/mal-steps.png"
 tags:
   - C++20
   - CMake
@@ -17,4 +17,77 @@ Repository at
 [Gitea](https://git.riyyi.com/riyyi/blaze){target="_blank"}.
 </small>
 
-TODO
+After having implemented the JSON serializer for my [utility
+library](/articles/utility-library), I became interested in interpreters. The
+utility library just has the `tokenization` step of an interpreter, so my tought
+was, what's next? That's right, `parsing`.
+
+Having used Emacs quite a bit, I wasn't shy of Lisp. Then, I came across the MAL
+([Make a Lisp](https://github.com/kanaka/mal){target="_blank"}) project, and
+decided to look into it. The project lays out the implementation steps of making
+a Lisp programming language in 10 or so steps and also provides you with unit
+tests that have to pass to proceed to the next step. There are also a bunch of
+reference implementations to refer to, in case you get stuck.
+
+Feeling like implementing a fully interpreted language was a bit of an
+undertaking and realizing that in a Lisp `parsing` and `interpreting` is
+basically combined into one step, it seemed achievable and I decided to give the
+MAL project a go.
+
+The final architechture that has to be implemented is pictured below.
+
+<div class="row">
+<div class="col-lg-9 col-xl-6">
+
+![](/img/mal-steps.png "")
+
+</div>
+</div>
+
+I managed to do a full implementation, including `variables`, `if` statements,
+`loops`, `functions`, `try/catch` exceptions, `lists`, `arrays`, `hash-maps` and
+even `macros`.
+
+With the REPL you can try things out and play around easily.
+
+
+```
+./repl
+Blaze [C++]
+user>
+```
+
+```elisp
+user> 123
+123
+user> (+ 1 2.5)
+3.5
+user> (- 10 (- 5 3))
+8
+user> "hello world"
+"hello world"
+user> (= 2 3)
+true
+user> (if (> 2 4) "yes" "no")
+"no"
+user> (count (list 3 6 2 9))
+4
+user> (count '(3 6 2 9)) ; list shorthand
+4
+user> (list? [2.1 nil "text"]) ; array / vector
+false
+user> {:a (+ 7 8)} ; hash-map
+{"a" 15}
+user> (def! mul (fn* [x y] (* x y))) ; defining a function
+#<user-function>(0x5f35f38815d0)
+user> (mul 4 5)
+20
+```
+
+This project was really interesting and the language is quite powerful, powerful
+enough to accomplish self-hosting! This means that an interpreter (or rather,
+eval+apply) _for_ this language, can be written _in_ the language.
+
+If you're curious about reading more examples, a good place is probably the
+testsuite for the project, those have a bunch of unit tests and are available
+[here](https://github.com/kanaka/mal/tree/master/impls/tests).