https://blog.leavitt.dev/tags/fsharp/ Recent content in Fsharp on Corey Leavitt Hugo en-us Fri, 31 Jul 2026 00:00:00 +0000 https://blog.leavitt.dev/posts/presence-lock-functional-core/ Fri, 31 Jul 2026 00:00:00 +0000 https://blog.leavitt.dev/posts/presence-lock-functional-core/ PresenceLock locks your Windows session when you step away from the webcam. The lock decision is a pure F# function of state, time, and events, with no clocks and no I/O, so the part that matters is testable without a camera or Windows at all.