ian erik varataluphd student at taltech, working on automata theory, algorithms, fast search engines and solvers.https://iev.ee/en-uswhat 262,715 regex questions on stack overflow haven't answeredhttps://iev.ee/blog/what-262715-regex-questions-havent-answered/https://iev.ee/blog/what-262715-regex-questions-havent-answered/complement, intersection, and why the most common regex workarounds are hundreds of times slower than they need to beSun, 10 May 2026 00:00:00 GMTfinding all regex matches has always been O(n²). even in the engines built to prevent ithttps://iev.ee/blog/the-quadratic-problem-nobody-fixed/https://iev.ee/blog/the-quadratic-problem-nobody-fixed/every regex engine that promises linear time breaks that promise the moment you ask for all matches. the problem has been there since the 70s, hiding in the iteration loop.Mon, 16 Mar 2026 00:00:00 GMTsymbolic derivatives and the rust rewrite of RE#https://iev.ee/blog/symbolic-derivatives-and-the-rust-rewrite-of-resharp/https://iev.ee/blog/symbolic-derivatives-and-the-rust-rewrite-of-resharp/Sun, 08 Mar 2026 00:00:00 GMTRE#: how we built the world's fastest regex engine in F#https://iev.ee/blog/resharp-how-we-built-the-fastest-regex-in-fsharp/https://iev.ee/blog/resharp-how-we-built-the-fastest-regex-in-fsharp/Sun, 22 Feb 2026 00:00:00 GMTconcretization, or how 10 lines of rust got me a dangling pointer and undefined behaviorhttps://iev.ee/blog/concretization-dangling-pointer-in-rust/https://iev.ee/blog/concretization-dangling-pointer-in-rust/Wed, 11 Feb 2026 00:00:00 GMTgzip decompression in 250 lines of rusthttps://iev.ee/blog/gzip-decompression-in-250-lines-of-rust/https://iev.ee/blog/gzip-decompression-in-250-lines-of-rust/Thu, 05 Feb 2026 00:00:00 GMTwhy use F# for scripting and automation?https://iev.ee/blog/why-use-fsharp/https://iev.ee/blog/why-use-fsharp/Wed, 04 Feb 2026 00:00:00 GMTstarting a dev/research bloghttps://iev.ee/blog/starting-a-dev-research-blog/https://iev.ee/blog/starting-a-dev-research-blog/Tue, 03 Feb 2026 00:00:00 GMT