15:I[981,["658","static/chunks/658-a698693f56d0116a.js","183","static/chunks/183-6beeeb801c274aaa.js","474","static/chunks/app/%5Btype%5D/layout-631c4730b83c8223.js"],"Posts"] 16:T4c6,Hi HN! I’m Hamachang, a Rubyist from Japan.

I’d like to share a project I’ve been working on for quite some time: Ruby-TI, a static type checker / type analyzer for mruby — now at major version 1.0!

Ruby-TI is written in Go and performs parse → type inference → type checking on mruby code. If you’re embedding mruby or writing mruby scripts, it can help catch type issues before runtime — something that’s often missing in dynamic languages like Ruby.

What Ruby-TI does

Parses mruby source code

Infers types and checks for type errors

Helps find type mismatches early

Includes editor integrations (e.g., LSP support) for better development experience

Why this matters

mruby is a lightweight, embeddable implementation of Ruby, great for scripting in applications or constrained environments. Catching type errors statically can save debugging time and increase confidence in your code — even without annotations.

Try it out

https://github.com/engneer-hamachan/ruby-ti

I’d love to hear feedback — issues, feature requests, or anything you find interesting!17:T42f,Most AI startup idea lists focus on what’s new or impressive.

What interested me more was what suddenly became possible.

There are many problems people have complained about for years, slow reviews, messy handoffs, manual ops, constant back-and-forth, that never quite worked as software businesses.

Not because the problems were small, but because automation was too costly or brittle.

AI changes that. It lowers the cost of replacing human effort just enough for these ideas to cross the viability threshold.

The result isn’t flashy products, but practical ones that quietly save time or money.

I spent time collecti

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