Merge #368

368: Mod over const r=korken89 a=AfoHT

Related [RFC](https://github.com/rtic-rs/rfcs/pull/34)

Dependent on [rtic-syntax-PR30](https://github.com/rtic-rs/rtic-syntax/pull/30)

~~Currently using my own dev-branch~~

Co-authored-by: Henrik Tjäder <henrik@tjaders.com>

1 files changed, 12 insertions, 12 deletions

diff --git a/book/en/src/internals/critical-sections.md b/book/en/src/internals/critical-sections.md
index f95a5a7..a064ad0 100644
--- a/book/en/src/internals/critical-sections.md
+++ b/book/en/src/internals/critical-sections.md
@@ -32,7 +32,7 @@ The example below shows the different types handed out to each task:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mut app {
     struct Resources {
         #[init(0)]
         x: u64,
@@ -57,7 +57,7 @@ const APP: () = {
     }
 
     // ..
-};
+}
 ```
 
 Now let's see how these types are created by the framework.
@@ -99,7 +99,7 @@ pub mod bar {
     }
 }
 
-const APP: () = {
+mod app {
     static mut x: u64 = 0;
 
     impl rtic::Mutex for resources::x {
@@ -129,7 +129,7 @@ const APP: () = {
             // ..
         })
     }
-};
+}
 ```
 
 ## `lock`
@@ -225,7 +225,7 @@ Consider this program:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     struct Resources {
         #[init(0)]
         x: u64,
@@ -277,7 +277,7 @@ const APP: () = {
     }
 
     // ..
-};
+}
 ```
 
 The code generated by the framework looks like this:
@@ -315,7 +315,7 @@ pub mod foo {
     }
 }
 
-const APP: () = {
+mod app {
     use cortex_m::register::basepri;
 
     #[no_mangle]
@@ -368,7 +368,7 @@ const APP: () = {
     }
 
     // repeat for resource `y`
-};
+}
 ```
 
 At the end the compiler will optimize the function `foo` into something like
@@ -430,7 +430,7 @@ handler through preemption. This is best observed in the following example:
 
 ``` rust
 #[rtic::app(device = ..)]
-const APP: () = {
+mod app {
     struct Resources {
         #[init(0)]
         x: u64,
@@ -484,7 +484,7 @@ const APP: () = {
         // ..
     }
 
-};
+}
 ```
 
 IMPORTANT: let's say we *forget* to roll back `BASEPRI` in `UART1` -- this would
@@ -493,7 +493,7 @@ be a bug in the RTIC code generator.
 ``` rust
 // code generated by RTIC
 
-const APP: () = {
+mod app {
     // ..
 
     #[no_mangle]
@@ -513,7 +513,7 @@ const APP: () = {
         // BUG: FORGOT to roll back the BASEPRI to the snapshot value we took before
         basepri::write(initial);
     }
-};
+}
 ```
 
 The consequence is that `idle` will run at a dynamic priority of `2` and in fact