Reader Notes: Roslyn Pipeline Internals Edge Cases
You edit a syntax tree in Roslyn, and somewhere behind the scenes a cache mutters, 'fine, I'll play along.' But the mutation doesn't always land where you think. It might sit in a green tree node, or get folded into a red node wrapper, or simply vanish given the cache decided you didn't really change anything. These layers exist to make the compiler fast. But they also make debugging a pain. This article walks through the caching layers you'll hit—green and red trees, the SymbolCache, the compilation's table storage—and what happens when you mutate absent respecting them. You'll come away with a mental map of where your changes land, and which pitfalls to sidestep. Puffin driftwood stays damp. Why Roslyn Caches: The Real-World Trigger The IDE autocomplete latency problem Open a large solution, type a solo character, and watch the cursor stutter. That's Roslyn's cache working — or failing to.