Crate glsl_lang

glsl-lang is a crate implementing a LALR parser for the GLSL 4.x language, with partial support for preprocessor directives. Its AST and features are modeled after Dimitri Sabadie’s glsl crate.

See the homepage for more detailed comparison elements.

Examples

Parsing GLSL

use glsl_lang::{ast, parse::DefaultParse};

// Some GLSL source to parse
let source = r#"void main() {
    gl_FragColor = vec4(1., 0.5, 0.25, 1.);
}"#;

// Try parsing the source
let ast = ast::TranslationUnit::parse(source);
assert!(ast.is_ok());

Crate features

This crate has the following features:

• parser-expr: generate parser code for parsing GLSL expressions
• parser-statement: generate parser code for parsing GLSL statements

None of these features are enabled by default, as they significantly increase the compile times. As an alternative, you may use the Parsable trait, which wraps grammar rules in suitable source and matches the result to extract the part of the AST we’re interested in.

// parse::Parse is not implemented for ast::Expr with the default features
use glsl_lang::{ast, parse::Parsable};

let source = "a = b ? 1.0 : 0.0";

// Parse with Parsable::parse
let ast = ast::Expr::parse(source);
assert!(ast.is_ok());

Useful links

• The OpenGL Shading Language Version 4.60

Re-exports

• pub use glsl_lang_lexer as lexer;

Modules

• ast
  GLSL abstract syntax tree and grammar.
• parse
  Parsing utilities and entry points
• parser 🔒
• transpiler
  GLSL transpilers – i.e. going from GLSL to anything else.
• visitor
  AST visitors (i.e. on-the-fly mutation at different places in the AST).