shilangyu.dev Blogging about programming languages, math, or things in between. https://shilangyu.dev/blog Adding lookbehinds to `rust-lang/regex` An annotated guide to adding captureless lookbehinds to the Rust linear-time regex engine. https://shilangyu.dev/blog/lookbehinds-rust-regex https://shilangyu.dev/blog/lookbehinds-rust-regex Tue, 15 Jul 2025 00:00:00 GMT Hacking co-/contra- variant generics Small overview of subtyping and variance in Dart motivated by a real example. Then, we hack variance into the language despite not supporting it directly. https://shilangyu.dev/blog/variance-hacking https://shilangyu.dev/blog/variance-hacking Fri, 17 Nov 2023 00:00:00 GMT Solving balanced parentheses problem using Dart's type system Using new features introduced in Dart 3, we solve and prove the solution to balanced parentheses problem. https://shilangyu.dev/blog/balanced-parentheses-dart-3 https://shilangyu.dev/blog/balanced-parentheses-dart-3 Sun, 30 Apr 2023 00:00:00 GMT Support Vector Machines explained Explaining the underlying math of SVMs. https://shilangyu.dev/blog/svm-explained https://shilangyu.dev/blog/svm-explained Sat, 26 Nov 2022 00:00:00 GMT