Wow I should ahve committed a long time ago

Going down a rabbit hole trying to make a parser macro.
Learning how to make a proc macro is... a steep learning curve.

.cargo/config.toml

@@ -25,6 +25,10 @@ rustflags = [
 
 [target.x86_64-pc-windows-msvc]
 linker = "rust-lld.exe" # Use LLD Linker
+rustflags = [
+  "-Zshare-generics=n", # This needs to be off if you use dynamic linking on Windows.
+  "-Zthreads=0"
+]
 
 [target.wasm32-unknown-unknown]
 runner = "wasm-server-runner"

Cargo.toml

@@ -3,8 +3,14 @@ name = "acts-of-gods"
 version = "0.1.0"
 edition = "2021"
 
+[workspace]
+members = [
+	"crates/*"
+]
+
 [dependencies]
-bevy = { version = "0.14", features = ["file_watcher", "dynamic_linking"] }
+parser = { path = "crates/parser" }
+bevy = { version = "0.14", features = ["file_watcher"] } # , "dynamic_linking"] }
 wee_alloc = "*"
 bevy_mod_picking = "0.20"
 thiserror = "1"
@@ -12,17 +18,17 @@ nom = "7"
 # Entity Uuid parsing
 uuid = "1.7.0"
 
-# Enable a small amount of optimization in debug mode
 [profile.dev]
 opt-level = 1
 
-# Enable high optimizations for dependencies (incl. Bevy), but not for our code:
 [profile.dev.package."*"]
 opt-level = 3
 
-# Prioritize binary size for wasm
+[profile.release]
+codegen-units = 1
+lto = "thin"
+
 [profile.wasm-release]
 inherits = "release"
-opt-level = "z"
-lto = "fat"
-codegen-units = 1
+opt-level = "s"
+strip = "debuginfo"

assets/editor/_.scene

@@ -0,0 +1,4 @@
+entities/camera.entity
+entities/ui_container.entity
+entities/ui_title.entity
+entities/window.entity

assets/levels/00/_.scene

@@ -0,0 +1,2 @@
+entities/camera.entity
+entities/van.entity

crates/parser/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "parser"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+nom = "7"
+syn = "2"
+quote = "1"

crates/parser/src/lib.rs

@@ -0,0 +1,92 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, token::Paren, Expr, Ident, Type, TypeTuple};
+
+#[derive(Debug)]
+enum Component {
+    // Members(Vec<Component>),
+    Member {
+        tag: Ident,
+        inputs: Vec<Type>,
+    }
+}
+
+impl syn::parse::Parse for Component {
+    fn parse(input: syn::parse::ParseStream) -> syn::parse::Result<Self> {
+        // TODO: Handle components with multiple struct members
+        let tag: Ident = input.parse()?;
+        let mut inputs = Vec::new();
+        while let Ok(ty) = input.parse() {
+            inputs.push(ty)
+        }
+        Ok(Component::Member { tag, inputs })
+    }
+}
+
+///
+/// Macro for generating parsing functions for entity components.
+/// 
+/// ```
+/// let line = "foo 1.2 2.3";
+/// let (x, y) = parse!("foo <f32> <f32>")(line).unwrap();
+/// ```
+/// 
+#[proc_macro]
+pub fn parse(tokens: TokenStream) -> TokenStream {
+    match parse_macro_input!(tokens as Component) {
+        Component::Member { tag, inputs } => {
+            // For each input value
+            //  nom::character::complete::space1,
+            // Match on type to determine parsing function (either float or string likely)
+            //  nom::number::complete::float,
+            let parsers = Vec::new();
+            let nom_tuple = quote! {
+                nom::bytes::complete::tag("#tag"),
+                #(nom::character::complete::space1, #parsers),*
+            };
+
+            let parsed_vars = Vec::new();
+            let nom_results = quote! {
+                #(#parsed_vars),*
+            };
+
+            let nom_output_type = quote! { #(#inputs),* };
+            let nom_outputs = quote! {
+                // (x1, x2, ...)
+            };
+
+            let expanded = quote! {
+                |line: &str| -> Result<#nom_output_type, nom::Err<_>> {
+                    tuple(#nom_tuple)(line).map(|(_, #nom_results)| #nom_outputs)
+                }
+            };
+
+            TokenStream::from(expanded)
+        }
+    }
+}
+
+// let t = nom::bytes::complete::take_while1(nom::character::is_alphabetic)(todo!()).unwrap();
+
+// let return_type = todo!();
+// let method_body = todo!();
+
+// let return_type = "Result<(f32, f32, f32), nom::Err<()>>";
+// let method_body = "
+//     nom::sequence::tuple((
+//         nom::bytes::complete::tag(\"thing\"),
+//         nom::character::complete::space1,
+//         nom::number::complete::float,
+//         nom::character::complete::space1,
+//         nom::number::complete::float,
+//         nom::character::complete::space1,
+//         nom::number::complete::float
+//     ))(line)
+//     .map(|(_, (_, _, x, _, y, _, z))| {
+//         (x, y, z)
+//     })
+// ";
+
+// let lambda = format!("|line: &str| -> {} {{ {} }}", return_type, method_body);
+
+// lambda.parse().unwrap()

examples/parser.rs

@@ -0,0 +1,7 @@
+use parser::parse;
+
+fn main() {
+	let line = "thing 1.23 3.45 5.67";
+	let f = parse!(thing f32 f32 f32);
+	let (_x, _y, _z) = f(line).unwrap();
+}

src/prelude.rs

@@ -20,6 +20,4 @@ pub(crate) use nom::{
 pub(crate) use uuid::Uuid;
 pub(crate) use thiserror::Error;
 
-pub(crate) use crate::{
-	conditions::*,
-};
+pub(crate) use crate::conditions::*;

src/save.rs

@@ -11,10 +11,11 @@ impl Plugin for SavePlugin {
             .register_type::<GltfScene>()
             .init_asset::<SaveEntity>()
             .init_asset_loader::<SaveEntityLoader>()
-            .add_systems(Startup, test_save_entity)
+            .init_asset_loader::<SaveSceneLoader>()
+            .add_systems(Startup, test_load_entity)
             .add_systems(
                 Update,
-                check_loaded_entity_assets.run_if(on_event::<AssetEvent<SaveEntity>>()),
+                spawn_loaded_entities.run_if(on_event::<AssetEvent<SaveEntity>>()),
             );
     }
 }
@@ -58,6 +59,7 @@ impl SaveEntity {
 }
 
 #[derive(Component, Clone, Debug, Reflect, PartialEq)]
+#[reflect(Component)]
 struct GltfScene {
     gltf: Handle<Gltf>,
     name: String,
@@ -67,6 +69,17 @@ struct GltfScene {
 mod parse {
     use super::*;
 
+    use parser::parse;
+
+    #[test]
+    fn test_parse_macro() {
+        let line = "thing 1.23 3.45 5.67";
+        let f = parse!(thing f32 f32 f32);
+        let result = f(line);
+        assert_eq!(Ok((1.23, 3.45, 5.67)), result);
+
+    }
+
     #[derive(Error, Debug)]
     pub(crate) enum SaveEntityParseError {
         #[error("Failed to parse Uuid: {0}")]
@@ -193,21 +206,24 @@ mod parse {
 
 
     #[derive(Component, Clone, Debug, Reflect, PartialEq)]
-    pub(crate) struct EntityUuid(Uuid);
+    #[reflect(Component)]
+    pub(crate) struct EntityUuid {
+        id: String
+    }
 
     ///
     ///
     pub(crate) fn parse_save_uuid(line: &str) -> Result<EntityUuid, SaveEntityParseError> {
         let (remainder, _) = tag("uuid")(line)?;
-        let uuid = Uuid::try_parse(remainder.trim())?;
-        Ok(EntityUuid(uuid))
+        let id = remainder.trim().into();
+        Ok(EntityUuid { id })
     }
 
     #[test]
     fn test_parse_uuid() {
         let line = "uuid 1c16ab9a-5f79-4340-8469-4086f69c64f2";
         let parsed = parse_save_uuid(line).unwrap();
-        let expected = EntityUuid(Uuid::parse_str("1c16ab9a-5f79-4340-8469-4086f69c64f2").unwrap());
+        let expected = EntityUuid { id: "1c16ab9a-5f79-4340-8469-4086f69c64f2".into() };
 
         assert_eq!(parsed, expected);
     }
@@ -237,7 +253,8 @@ mod parse {
         assert_eq!(parsed, expected);
     }
 
-    #[derive(Debug, Default, PartialEq, Reflect)]
+    #[derive(Component, Debug, Default, PartialEq, Reflect, Clone)]
+    #[reflect_value(Component, Default)]
     pub(crate) enum SaveCameraRenderTarget {
         #[default]
         Default,
@@ -347,7 +364,44 @@ impl AssetLoader for SaveEntityLoader {
     }
 }
 
-fn test_save_entity(loader: Res<AssetServer>, mut commands: Commands) {
+#[derive(Default)]
+struct SaveSceneLoader;
+
+impl AssetLoader for SaveSceneLoader {
+    type Asset = DynamicScene;
+    type Settings = ();
+    type Error = SaveEntityLoaderError;
+
+    async fn load<'a>(
+        &'a self,
+        reader: &'a mut Reader<'_>,
+        _settings: &'a (),
+        load_context: &'a mut LoadContext<'_>,
+    ) -> Result<Self::Asset, Self::Error> {
+        let mut bytes = Vec::new();
+        reader.read_to_end(&mut bytes).await?;
+
+        let s = std::str::from_utf8(bytes.as_slice()).unwrap();
+
+        let asset_path = load_context.path().to_path_buf();
+        let parent_dir = asset_path.parent().unwrap();
+        let _sub_assets: Vec<Handle<SaveEntity>> = s.lines().map(|line| {
+            parent_dir.join(line)
+        }).map(|path| {
+            load_context.load(path)
+        }).collect();
+
+        Ok(DynamicScene::default())
+    }
+
+    fn extensions(&self) -> &[&str] {
+        &["scene"]
+    }
+}
+
+
+fn test_load_entity(loader: Res<AssetServer>, mut commands: Commands) {
+    let _: Handle<DynamicScene> = loader.load("editor/_.scene");
     let handle: Handle<SaveEntity> = loader.load("levels/00/entities/van.entity");
     commands.spawn((
         SpatialBundle { ..default() },
@@ -355,7 +409,7 @@ fn test_save_entity(loader: Res<AssetServer>, mut commands: Commands) {
     ));
 }
 
-fn check_loaded_entity_assets(
+fn spawn_loaded_entities(
     query: Query<(Entity, &Handle<SaveEntity>)>,
     mut events: EventReader<AssetEvent<SaveEntity>>,
     save_entities: Res<Assets<SaveEntity>>,
@@ -369,7 +423,11 @@ fn check_loaded_entity_assets(
                 .for_each(|(entity, _handle)| {
                     let saved = save_entities.get(*id).unwrap();
 
+                    // Get entity with SaveEntity handle
                     let mut e = commands.entity(entity);
+                    // Clear the entity
+                    e.despawn_descendants();
+                    // Populate with reflected components
                     saved.components.iter().for_each(|dc| {
                         e.insert_reflect(dc.clone_value());
                     });