Ask HN: What are some tools / libraries you built yourself?

Lead Engineer at PAX Labs, we just open-sourced some Java utilities i wrote in the early days building service oriented architecture on dropwizard: https://github.com/PaxLabs/java-utils

A few things in there:

* `HibernateQuery` - wrapper around hibernate jpa implementation, because using the jpa criteria api is verbose as hell (seriously, even for java). Coming from having written Django, I wanted the ease of using Querysets in java

* Makemigrations - this seemed to be a missing hole in the java ecosystem. Our contractors were hand-writing sql migrations and using some framework that just ran them. Liquibase exists for managing migrations, hibernate can generate the schemas. This library is a dropwizard command to generate yml to migrate the old schema to the new one.

* generic pagination bundle

I do quite a bit of data munging on multiprocessor Unix systems, and found (some remarkably lightweight) homemade Rust/py tools invaluable for getting stuff done.

A low-memory Unix map-reduce combinator - https://github.com/vlad17/slb

A sparse matrix parser (cpython equivalents are not parallel) - https://github.com/vlad17/svm2csr

A personal task planner when doing high-risk work which minimizes time to failure - https://github.com/vlad17/fdd

A Python program to make an embeddable search engine for a static website: https://github.com/joe-crawford/Static-Site-Search

It indexes the site and generates search functionality in JavaScript (the index is just a static JSON file) that can be uploaded wherever JS/HTML/etc. files can be uploaded. I thought it might be useful for people with sites on GitHub pages or similar who don't want to use one of the major search engine company widgets.

Also my back of the envelope calculations were that the simple search index for a small–medium site won't be that big.

I wrote Helium https://github.com/geuis/helium-css a while back to help find unused css on a site. The process of building sites has changed a lot since then so it’s not as universally useful as it used to be. (...Glares at React...). Joking aside, it’s had a good run. I’ve had some ideas for a few years about an updated version but it would really be an entire new project.

Also created https://jsonip.com. Get your IP address in a json object. I created it a decade ago to solve some problem I had and have been running it ever since. Last I checked it’s supporting 4-6 million requests per day from a pretty wide group of users.

I made a small utility to help me search for JS code better. It's called @nikhilverma/ast-grep. It works really well for my use case but I hope to polish it more and release it more widely.

npx @nikhilverma/ast-grep '{ meta: { title: "___" }}' src/

This will search for any object with a key meta which is also an object and has a property called title which is any string. It uses AST for grepping so you don't need to worry about placement, whitespaces etc.