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diff --git a/crates/ra-salsa/FAQ.md b/crates/ra-salsa/FAQ.md deleted file mode 100644 index 9c9f6f92da..0000000000 --- a/crates/ra-salsa/FAQ.md +++ /dev/null @@ -1,34 +0,0 @@ -# Frequently asked questions - -## Why is it called salsa? - -I like salsa! Don't you?! Well, ok, there's a bit more to it. The -underlying algorithm for figuring out which bits of code need to be -re-executed after any given change is based on the algorithm used in -rustc. Michael Woerister and I first described the rustc algorithm in -terms of two colors, red and green, and hence we called it the -"red-green algorithm". This made me think of the New Mexico State -Question --- ["Red or green?"][nm] --- which refers to chile -(salsa). Although this version no longer uses colors (we borrowed -revision counters from Glimmer, instead), I still like the name. - -[nm]: https://www.sos.state.nm.us/about-new-mexico/state-question/ - -## What is the relationship between salsa and an Entity-Component System (ECS)? - -You may have noticed that Salsa "feels" a lot like an ECS in some -ways. That's true -- Salsa's queries are a bit like *components* (and -the keys to the queries are a bit like *entities*). But there is one -big difference: **ECS is -- at its heart -- a mutable system**. You -can get or set a component of some entity whenever you like. In -contrast, salsa's queries **define "derived values" via pure -computations**. - -Partly as a consequence, ECS doesn't handle incremental updates for -you. When you update some component of some entity, you have to ensure -that other entities' components are updated appropriately. - -Finally, ECS offers interesting metadata and "aspect-like" facilities, -such as iterating over all entities that share certain components. -Salsa has no analogue to that. - |