Lib.rs

🌺 Nolana

Nolana is an extremely fast parser for Molang.

Project goals, in roughly descending priority:

• Be fully compliant with Molang
• Optimize for speed while maintaining a user-friendly AST
• Ensure the parser can recover from most syntax errors
• Provide extra tools for code generation (printing), simple semantic analysis, and AST traversal

⚡ Performance

Run just bench to try the benchmarks.

test parser  ... bench:         593 ns/iter (+/- 5)
test codegen ... bench:         182 ns/iter (+/- 1)

CPU: Intel Core i5-12400F

Nolana achieves this performance by leveraging logos as its lexer, avoiding unnecessary allocations by using an arena allocator, and ensuring the memory size of each AST node is small.

📝 Example

use nolana::{
    allocator::Allocator,
    codegen::{Codegen, CodegenOptions},
    parser::{Parser, ParserReturn},
    semantic::SemanticChecker,
};

let source_text = "math.cos(q.anim_time * 38) * v.rotation_scale + v.x * v.x * q.life_time";

// Create an arena allocator to store the AST nodes.
let allocator = Allocator::default();

// Parse the provided Molang source code.
let ParserReturn {
    program,
    errors,
    panicked,
} = Parser::new(&allocator, source_text).parse();

// Check for syntax errors.
if !errors.is_empty() {
    for error in errors {
        let error = error.with_source_code(source_text);
        print!("{error:?}");
    }
    if panicked {
        println!("Encountered an unrecoverable error");
    }
    return;
}

// Pretty print the AST.
println!("AST: {:#?}", program);

For more examples, check the examples directory.

📖 License

Nolana is free and open-source software distributed under the MIT License.