Redesign ComponentAccessExpr, improve error diagnostics (#35)

This PR redesigns the `ComponentAccessExpr` type to track access
conflicts more precisely. Queries such as `Or<Or<(&mut A, With<&B>),
(&A, Not<&B>)>, (&A, Not<&B>)>` and `(&mut A, &mut A, Not<&A>)` will now
pass the component access checker.

Additionally, we now defer access errors until after handler init has
finished. This improves diagnostics by showing a list of all access
conflicts together.

## TODO

- [x] Clean up warnings

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Change Log
 
+## Unreleased
+
+- Redesign component access checking. Complex queries will now pass the component access checker in more cases.
+- Improve diagnostics for component access errors.
+- Redesign `Config` interface to hide implementation details. (Now named `HandlerConfig`).
+- Removed `bit_set` module from public API.
+
 ## 0.4.2 - 2024-03-24
 
 - Fixed bug in entity despawning.

evenio_macros/src/handler_param.rs

@@ -122,7 +122,7 @@ pub(crate) fn derive_handler_param(input: TokenStream) -> Result<TokenStream> {
 
             fn init(
                 world: &mut ::evenio::world::World,
-                config: &mut ::evenio::handler::Config,
+                config: &mut ::evenio::handler::HandlerConfig,
             ) -> ::core::result::Result<Self::State, ::evenio::handler::InitError>
             {
                 <#tuple_ty as ::evenio::handler::HandlerParam>::init(world, config)

evenio_macros/src/query.rs

@@ -122,8 +122,8 @@ pub(crate) fn derive_query(input: TokenStream) -> Result<TokenStream> {
 
             fn init(
                 world: &mut ::evenio::world::World,
-                config: &mut ::evenio::handler::Config
-            ) -> ::core::result::Result<(::evenio::access::ComponentAccessExpr, Self::State), ::evenio::handler::InitError>
+                config: &mut ::evenio::handler::HandlerConfig
+            ) -> ::core::result::Result<(::evenio::access::ComponentAccess, Self::State), ::evenio::handler::InitError>
             {
                 <#tuple_ty as ::evenio::query::Query>::init(world, config)
             }