From b570c7789d13c12f159a53b39172163f5d1c8491 Mon Sep 17 00:00:00 2001
From: SeanOMik <seanomik@gmail.com>
Date: Wed, 14 Aug 2024 16:27:33 -0400
Subject: [PATCH] Start work on struct imports

---
 src/lib.rs    | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/wgsl.pest | 10 ++++++
 2 files changed, 95 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index 3afc903..4ee9a76 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -293,4 +293,89 @@ fn main() -> vec4<f32> {
         assert!(out.contains("var<storage, read> light_indices"), "missing light_indices binding: {}", out);
         assert!(out.contains("var<storage, read_write> some_buffer"), "missing some_buffer binding: {}", out);
     }
+
+    #[test]
+    fn import_struct() {
+        const BINDINGS_MODULE: &'static str =
+r#"#define_module engine::lights
+
+struct Light {
+    intensity: f32
+}"#;
+
+        const IMPORTING_MODULE: &'static str =
+r#"#define_module engine::main
+#import engine::lights::{Light}
+
+fn main() -> vec4<f32> {
+    // imports must be used to be generated
+    let base_light = Light(1.0);
+
+    return vec4<f32>(1.0);
+}"#;
+
+        tracing_subscriber::fmt()
+            // enable everything
+            .with_max_level(tracing::Level::TRACE)
+            // sets this to be the default, global collector for this application.
+            .init();
+
+        let mut p = Processor::new();
+        p.parse_module(BINDINGS_MODULE).unwrap()
+            .expect("failed to find bindings module def");
+        let importing_mod = p.parse_module(IMPORTING_MODULE).unwrap()
+            .expect("failed to find main module def");
+
+        let out = p.process_file(&importing_mod, &IMPORTING_MODULE).unwrap();
+
+        assert!(out.contains("struct Light"), "missing `Light` struct definition: {}", out);
+    }
+
+    /* #[test]
+    fn import_type_aliases() {
+        const BINDINGS_MODULE: &'static str =
+r#"#define_module engine::aliases
+
+struct Light {
+    intensity: f32
+}
+
+struct Lights {
+    num: u32,
+    data: array<Light>
+}
+
+alias LightArray = Lights;"#;
+
+        const IMPORTING_MODULE: &'static str =
+r#"#define_module engine::main
+#import engine::aliases::{LightArray}
+
+@group(0) @binding(0) var<uniform> lights: LightArray;
+
+fn main() -> vec4<f32> {
+    // imports must be used to be generated
+    let light_num = lights.num;
+
+    return vec4<f32>(1.0);
+}"#;
+
+        tracing_subscriber::fmt()
+            // enable everything
+            .with_max_level(tracing::Level::TRACE)
+            // sets this to be the default, global collector for this application.
+            .init();
+
+        let mut p = Processor::new();
+        p.parse_module(BINDINGS_MODULE).unwrap()
+            .expect("failed to find bindings module def");
+        let importing_mod = p.parse_module(IMPORTING_MODULE).unwrap()
+            .expect("failed to find main module def");
+
+        let out = p.process_file(&importing_mod, &IMPORTING_MODULE).unwrap();
+
+        assert!(out.contains("alias LightArray = Lights"), "missing use_anyway binding: {}", out);
+        assert!(out.contains("struct Light"), "missing `Light` struct definition: {}", out);
+        assert!(out.contains("struct Lights"), "missing `Lights` struct definition: {}", out);
+    } */
 }
\ No newline at end of file
diff --git a/src/wgsl.pest b/src/wgsl.pest
index 392e697..24fda3d 100644
--- a/src/wgsl.pest
+++ b/src/wgsl.pest
@@ -37,6 +37,14 @@ shader_value = { shader_value_bool | shader_value_num  }
 
 shader_var_type = { ":" ~ ws* ~ (shader_external_variable | shader_type) }
 shader_const_def = { "const" ~ ws ~ shader_ident ~ (ws* ~ shader_var_type)? ~ ws* ~ "=" ~ ws* ~ shader_value ~ ";" }
+shader_struct_def = {
+    "struct" ~ ws ~ shader_ident ~ ws* ~ "{" ~ NEWLINE ~
+        ws* ~ shader_ident ~ shader_var_type ~
+        ("," ~ NEWLINE ~ ws* ~ shader_ident ~ shader_var_type)* ~
+        ("," ~ NEWLINE)? ~ 
+    "}"
+}
+shader_type_alias_def = { "alias" ~ ws ~ shader_ident ~ ws* ~ "=" ~ ws* ~ (shader_external_variable | shader_type) ~ ";" }
 
 shader_group_binding = { "@group(" ~ NUMBER ~ ") @binding(" ~ NUMBER ~ ")" }
 shader_binding_var_constraint = {
@@ -58,8 +66,10 @@ shader_fn_def = {
 // a line of shader code, including white space
 shader_code_line = {
     shader_fn_def |
+    (shader_struct_def ~ newline?) |
     (shader_const_def ~ newline?) |
     (shader_binding_def ~ newline?) |
+    (shader_type_alias_def ~ newline?) |
     ws* ~ newline
 }
 //shader_code_line = { shader_fn_def | shader_const_def | (ws* ~ (shader_external_code | shader_code)* ~ ws*) }