feat: Expand const generic support to array lengths

Author: LukeMathWalker

compiler/ui_tests/reflection/const_generics_are_supported/diagnostics.dot

@@ -29,15 +29,17 @@ digraph "GET / - 0" {
 }
 
 digraph "GET / - 1" {
-    0 [ label = "0| app_e22d4bbe::character() -> app_e22d4bbe::CharConst<'a'>"]
-    1 [ label = "1| app_e22d4bbe::boolean() -> app_e22d4bbe::BoolConst<true>"]
-    2 [ label = "2| app_e22d4bbe::numeric() -> app_e22d4bbe::NumericConst<8>"]
-    3 [ label = "3| app_e22d4bbe::handler(app_e22d4bbe::NumericConst<8>, app_e22d4bbe::BoolConst<true>, app_e22d4bbe::CharConst<'a'>) -> pavex::Response"]
-    4 [ label = "4| <pavex::Response as pavex::IntoResponse>::into_response(pavex::Response) -> pavex::Response"]
-    0 -> 3 [ ]
-    1 -> 3 [ ]
-    2 -> 3 [ ]
+    0 [ label = "0| app_e22d4bbe::sized_array() -> app_e22d4bbe::SizedArray<4>"]
+    1 [ label = "1| app_e22d4bbe::character() -> app_e22d4bbe::CharConst<'a'>"]
+    2 [ label = "2| app_e22d4bbe::boolean() -> app_e22d4bbe::BoolConst<true>"]
+    3 [ label = "3| app_e22d4bbe::numeric() -> app_e22d4bbe::NumericConst<8>"]
+    4 [ label = "4| app_e22d4bbe::handler(app_e22d4bbe::NumericConst<8>, app_e22d4bbe::BoolConst<true>, app_e22d4bbe::CharConst<'a'>, app_e22d4bbe::SizedArray<4>) -> pavex::Response"]
+    5 [ label = "5| <pavex::Response as pavex::IntoResponse>::into_response(pavex::Response) -> pavex::Response"]
+    0 -> 4 [ ]
+    1 -> 4 [ ]
+    2 -> 4 [ ]
     3 -> 4 [ ]
+    4 -> 5 [ ]
 }
 
 digraph app_state {

compiler/ui_tests/reflection/const_generics_are_supported/expectations/app.rs

@@ -149,11 +149,12 @@ pub mod route_1 {
         <pavex::Response as pavex::IntoResponse>::into_response(v2)
     }
     async fn handler() -> pavex::Response {
-        let v0 = app::character();
-        let v1 = app::boolean();
-        let v2 = app::numeric();
-        let v3 = app::handler(v2, v1, v0);
-        <pavex::Response as pavex::IntoResponse>::into_response(v3)
+        let v0 = app::sized_array();
+        let v1 = app::character();
+        let v2 = app::boolean();
+        let v3 = app::numeric();
+        let v4 = app::handler(v3, v2, v1, v0);
+        <pavex::Response as pavex::IntoResponse>::into_response(v4)
     }
     struct Next0<T>
     where

compiler/ui_tests/reflection/const_generics_are_supported/expectations/diagnostics.dot

@@ -26,15 +26,17 @@ digraph "GET / - 0" {
     2 -> 3 [ ]
 }
 digraph "GET / - 1" {
-    0 [ label = "0| app::character() -> app::CharConst<'a'>"]
-    1 [ label = "1| app::boolean() -> app::BoolConst<true>"]
-    2 [ label = "2| app::numeric() -> app::NumericConst<8>"]
-    3 [ label = "3| app::handler(app::NumericConst<8>, app::BoolConst<true>, app::CharConst<'a'>) -> pavex::Response"]
-    4 [ label = "4| <pavex::Response as pavex::IntoResponse>::into_response(pavex::Response) -> pavex::Response"]
-    0 -> 3 [ ]
-    1 -> 3 [ ]
-    2 -> 3 [ ]
+    0 [ label = "0| app::sized_array() -> app::SizedArray<4>"]
+    1 [ label = "1| app::character() -> app::CharConst<'a'>"]
+    2 [ label = "2| app::boolean() -> app::BoolConst<true>"]
+    3 [ label = "3| app::numeric() -> app::NumericConst<8>"]
+    4 [ label = "4| app::handler(app::NumericConst<8>, app::BoolConst<true>, app::CharConst<'a'>, app::SizedArray<4>) -> pavex::Response"]
+    5 [ label = "5| <pavex::Response as pavex::IntoResponse>::into_response(pavex::Response) -> pavex::Response"]
+    0 -> 4 [ ]
+    1 -> 4 [ ]
+    2 -> 4 [ ]
     3 -> 4 [ ]
+    4 -> 5 [ ]
 }
 digraph app_state {
     0 [ label = "0| crate::ApplicationState() -> crate::ApplicationState"]

compiler/ui_tests/reflection/const_generics_are_supported/generated_app/src/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "application_e22d4bbe"
+version = "0.1.0"
+edition = "2021"
+
+[package.metadata.px.generate]
+generator_type = "cargo_workspace_binary"
+generator_name = "app_e22d4bbe"

compiler/ui_tests/reflection/const_generics_are_supported/generated_app/src/lib.rs

@@ -149,11 +149,12 @@ pub mod route_1 {
         <pavex::Response as pavex::IntoResponse>::into_response(v2)
     }
     async fn handler() -> pavex::Response {
-        let v0 = app_e22d4bbe::character();
-        let v1 = app_e22d4bbe::boolean();
-        let v2 = app_e22d4bbe::numeric();
-        let v3 = app_e22d4bbe::handler(v2, v1, v0);
-        <pavex::Response as pavex::IntoResponse>::into_response(v3)
+        let v0 = app_e22d4bbe::sized_array();
+        let v1 = app_e22d4bbe::character();
+        let v2 = app_e22d4bbe::boolean();
+        let v3 = app_e22d4bbe::numeric();
+        let v4 = app_e22d4bbe::handler(v3, v2, v1, v0);
+        <pavex::Response as pavex::IntoResponse>::into_response(v4)
     }
     struct Next0<T>
     where

compiler/ui_tests/reflection/const_generics_are_supported/src/lib.rs

@@ -3,6 +3,7 @@ use pavex::{blueprint::from, Blueprint};
 pub struct NumericConst<const N: usize>;
 pub struct BoolConst<const B: bool>;
 pub struct CharConst<const C: char>;
+pub struct SizedArray<const N: usize>(pub [u8; N]);
 
 #[pavex::request_scoped]
 pub fn numeric() -> NumericConst<8> {
@@ -19,11 +20,17 @@ pub fn character() -> CharConst<'a'> {
     CharConst
 }
 
+#[pavex::request_scoped]
+pub fn sized_array() -> SizedArray<4> {
+    SizedArray([0; 4])
+}
+
 #[pavex::get(path = "/")]
 pub fn handler(
     _n: NumericConst<8>,
     _b: BoolConst<true>,
     _c: CharConst<'a'>,
+    _s: SizedArray<4>,
 ) -> pavex::Response {
     todo!()
 }

rustdoc/rustdoc_resolver/src/resolve_type.rs

@@ -507,7 +507,12 @@ fn _resolve_type<I: CrateIndexer>(
             }))
         }
         RustdocType::Array { type_, len } => {
-            let len: usize = len.parse().map_err(|_| {
+            let resolved_len = generic_bindings
+                .consts
+                .get(len)
+                .map(|s| s.as_str())
+                .unwrap_or(len);
+            let len: usize = resolved_len.parse().map_err(|_| {
                 TypeResolutionErrorDetails::UnsupportedArrayLength(UnsupportedArrayLength {
                     len: len.clone(),
                 })