# 🛠️ HLSL Parser Developer Guide
Hlsl support for the Oak language framework.
This guide is designed to help you quickly get started with developing and integrating `oak-hlsl`.
## 🚦 Quick Start
Add the dependency to your `Cargo.toml`:
```toml
[dependencies]
oak-hlsl = { path = "..." }
```
### Basic Parsing Example
The following is a standard workflow for parsing an HLSL shader:
```rust
use oak_hlsl::{Parser, SourceText};
fn main() {
// 1. Prepare shader source code
let code = r#"
struct VS_INPUT {
float4 Pos : POSITION;
float2 Tex : TEXCOORD0;
};
struct VS_OUTPUT {
float4 Pos : SV_POSITION;
float2 Tex : TEXCOORD0;
};
float4x4 WorldViewProj;
VS_OUTPUT main(VS_INPUT input) {
VS_OUTPUT output;
output.Pos = mul(input.Pos, WorldViewProj);
output.Tex = input.Tex;
return output;
}
"#;
let source = SourceText::new(code);
// 2. Initialize parser
let parser = Parser::new();
// 3. Execute parsing
let result = parser.parse(&source);
// 4. Handle results
if result.is_success() {
println!("Parsing successful! AST node count: {}", result.node_count());
} else {
eprintln!("Errors found during parsing.");
for diag in result.diagnostics() {
println!("[{}:{}] {}", diag.line, diag.column, diag.message);
}
}
}
```
## 🔍 Core API Usage
### 1. Syntax Tree Traversal
After a successful parse, you can use the built-in visitor pattern or manually traverse the Green/Red Tree to extract HLSL constructs like shader entry points, constant buffer declarations, and resource bindings.
### 2. Incremental Parsing
Shader code often undergoes frequent small edits during development. `oak-hlsl` supports sub-millisecond incremental updates:
```rust
// Re-parse only the modified section
let new_result = parser.reparse(&new_source, &old_result);
```
### 3. Error Recovery
The parser is designed for industrial-grade fault tolerance, recovering gracefully from missing semicolons or malformed shader attributes to provide continuous feedback in IDEs.
## 🏗️ Architecture Overview
- **Lexer**: Tokenizes HLSL source text, supporting shader-specific keywords, semantics, and numeric literals with optional suffixes.
- **Parser**: A high-performance recursive descent parser with Pratt parsing for expressions, handling HLSL's operator precedence and complex vector/matrix math.
- **AST**: A strongly-typed, lossless syntax tree that preserves all trivia (comments/whitespace) for refactoring and formatting tools.
## 🔗 Advanced Resources
- **Full Examples**: Check the [examples/](examples/) folder in the project root.
- **API Documentation**: Run `cargo doc --open` for detailed type definitions.
- **Test Cases**: See [tests/readme.md](tests/readme.md) for details on our snapshot-based testing.