# 🛠️ Tcl Parser Developer Guide
Tcl support for the Oak language framework.
This guide is designed to help you quickly get started with developing and integrating `oak-tcl`.
## 🚦 Quick Start
Add the dependency to your `Cargo.toml`:
```toml
[dependencies]
oak-tcl = { path = "..." }
```
### Basic Parsing Example
The following is a standard workflow for parsing Tcl scripts, supporting commands, variables, and complex command substitutions:
```rust
use oak_tcl::{TclParser, SourceText, TclLanguage};
fn main() {
// 1. Prepare source code
let code = r#"
set name "Oak"
proc greet {msg} {
puts "$msg, $::name!"
}
greet "Hello"
"#;
let source = SourceText::new(code);
// 2. Initialize parser
let config = TclLanguage::new();
let parser = TclParser::new(&config);
// 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 Tcl specific constructs like commands, arguments, variable references, and scripts within braces.
### 2. Incremental Parsing
Tcl scripts are often used in embedded systems or as configuration. `oak-tcl` 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 unclosed braces or quotes to provide continuous feedback in IDEs.
## 🏗️ Architecture Overview
- **Lexer**: Tokenizes Tcl source text, supporting Tcl's unique "everything is a string" philosophy, command substitutions, and variable expansions.
- **Parser**: A high-performance recursive descent parser that handles Tcl's command-based structure and nested scripts.
- **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.