Tag: clojure

Structured logging in Clojure

tree logs photography
December 9, 2022
valeblog
0 Comment

The first time I ran into “structured logging” was way, way back when I first started working on kitsune. Back then I went with the approach of using a Logback Formatter (the JacksonJsonFormatter) to log Clojure maps as JSON. This was nice because I didn’t have to do anything to “transform” the logs further, but had the quite significant downside that logs weren’t really human readable anymore. This plus that that log processors like Loki and CloudWatch can easily parse huge amounts of “traditional” text logs made me pretty much forget about structured logging until recently.

That is until in a thread on the clojurians slack about logging someone mentioned mulog, a structured logging library that caught my attention. I guess maybe from a traditional Clojure background it would’ve been natural to end up with taoensso/timbre at this point, but I never did that bit (though I do have it as an indirect dependency).

Read More

自分でアドカレを作ってみた

December 4, 2022
valeblog
0 Comment

アドカレのブログでアドカレ作った話を書くのはさすがにちょっとメタすぎる気もするが、学ぶことは少なくなかったのでまとめる。思いの外スムーズにいったこともあって、小規模ながらもおもしろかった。

Read More

Hot reloading and reitit in the frontend

December 3, 2022
valeblog
0 Comment

Ever since I first ran into the Metosin libraries, I’ve been using many of them. One of the most known and used of those is probably reitit, a routing library that can be used both on the server and in the browser. Recently I’ve had more opportunities using ClojureScript in the browser, and I noticed something that was confusing for a few moments.

closeup photo of fox
Read More

reititはいいぞ

December 3, 2021
valeblog
0 Comment

reititはClojure/Scriptの高速なルーター。はい30文字。

brown wooden pathway on green grass field near brown rocky mountain under white clouds during daytime
Read More

What’s the deal with types?

October 17, 2021
valeblog
0 Comment

I’ve never used Haskell. I won’t claim I’m good at Rust. I mostly work with Ruby and Clojure, both dynamic languages where you don’t really need to worry about types. But then of course that’s not true. Even if you put Rails’s magic aside, it’s way too easy to write code that accidentally works (in an absolutely unintended fashion).

low-angle photography gray building
Read More

What’s an ideal database?

October 17, 2021
valeblog
0 Comment

I’ve been reading about and considering language design choices (for my new pet project), and one thing I really like (though I rarely actually use in action) is Clojure’s transducers. I couldn’t find it in the talk introducing them, but I vaguely recall someone vaguely recalling that Rich Hickey said Clojure’d have much less laziness if he’d found the idea of transducers sooner.

Then in a completely different thought process (maybe there could be transducers, process transformations for thought processes as well?) about databases. I was considering databases I used so far, things I tried to achieve with them, the difficulties and nice things.

Read More

Writing a lisp-ish compiler in Rust

October 13, 2021
valeblog
1 Comment

It was a while back that I got a notice from Shibuya lisp that the 100th event is coming up. It’s a (Common) Lisp/Clojure meetup in Tokyo (though since covid, online). I don’t know if it’s a common thing among lispers, but everyone there seems to at least try writing their own lisp (and talk about it) somewhere down the path.

Before I wasn’t that interested. I could do most of what I wanted to do in Clojure without too much pain. Then I tried writing a (performant) wrapper around Netty and it got a bit more painful. Things like nth calls on function argument lists started showing up on my flame charts (testing with 100 million requests) and rough edges around interop cut my hands (hello proxy and abstract classes).

Read More

Clojerlを使ってみる

tree roots on rock formation
December 16, 2020
valeblog
0 Comment

ErlangはEricssonがはるか昔に開発した通信環境用の言語で、ものすごく頑丈で安定している環境として有名。実際に世界中のモバイル通信環境で用いられ99.9999999% (“nine nines”) の可用性を誇っている。最近ではRuby風でErlangのBEAMを実行環境とするElixirが流行っている印象がある。分散を前提にしている関数型言語としてClojureに近いと感じた。そして実際にBEAMの上でClojureを実装しているものがある。

Clojureが最初はJVMと.NETのCLRも対象にしていたが後JVMだけになり、またClojureScriptの登場でJavaScript上で動くようになった。だから根本的なところは案外実行環境に依存しないところもあるかもしれない。BEAM上でClojureを実装しているClojerlはあくまでもコミュニティーからのもので正式なClojure版ではないが、試したかったBEAMと選べるなら選ぶぐらい好きなClojureが合ったものに当たるから触ってみざるをえなかった。

Read More

Down the __extmap rabbit hole

December 15, 2020
valeblog
0 Comment

Was trying to figure out what defrecord does in the impl of ILookup it generates and I absolutely do not understand that magic. Essentially it amounts to (get __extmap key)  and I can’t even figure out how this magical __extmap gets into scope (a global or some special runtime thing?) and this isn’t even used. Confused

zerusski on Clojurians Slack

This post on Clojurians sent me down the rabbit hole looking for where this “mysterious” __extmap comes from. It really isn’t obvious at first, but when I found it, it was “wow” times “duh”.

Read More

Clojure and Java functional interfaces

November 23, 2020
valeblog
1 Comment

Java 8 came out in 2014 and brought along functional interfaces. Functional in general just means that you can treat functions (or methods) as “things” instead of having no proper way to talk about them. In this sense Javascript for example is functional: you can pass around functions all you want. Java’s had Runnable and Callable that are pretty similar in concept.

Then came Java 8 and with it the “mighty arrows.” For some reason Ruby, Javascript and Java all opted to use the same bit of syntax to talk about lambdas (anonymous functions): ->. In Ruby it’s ->(foo) { foo }, in Javascript it’s (foo) -> foo, and surprisingly in Java it’s the same. Run a few rounds with futures and/or streaming stuff and you’ll definitely want to pass such a lambda to forEach for example.

Read More