What is meriyah?
Meriyah is a fast and lightweight JavaScript parser that supports the latest ECMAScript standards. It is designed to be highly performant and can be used for various tasks such as syntax analysis, code transformation, and static code analysis.
What are meriyah's main functionalities?
Parsing JavaScript Code
This feature allows you to parse JavaScript code into an Abstract Syntax Tree (AST). The code sample demonstrates how to parse a simple JavaScript statement and log the resulting AST.
const meriyah = require('meriyah');
const ast = meriyah.parseScript('const x = 10;');
console.log(ast);
Parsing with Options
Meriyah supports various parsing options such as module parsing and JSX syntax. The code sample shows how to parse a script with these options enabled.
const meriyah = require('meriyah');
const ast = meriyah.parseScript('const x = 10;', { module: true, jsx: true });
console.log(ast);
Error Handling
Meriyah provides error handling capabilities to catch and handle syntax errors during parsing. The code sample demonstrates how to catch a parsing error and log the error message.
const meriyah = require('meriyah');
try {
const ast = meriyah.parseScript('const x = ;');
} catch (e) {
console.error('Parsing error:', e.message);
}
Other packages similar to meriyah
acorn
Acorn is a small, fast, JavaScript-based JavaScript parser. It is known for its modularity and flexibility, allowing users to extend its functionality with plugins. Compared to Meriyah, Acorn is more extensible but may be slightly slower in performance.
esprima
Esprima is a high-performance, standard-compliant ECMAScript parser. It is widely used in various JavaScript tools and frameworks. Esprima is known for its accuracy and reliability, but Meriyah is generally faster and more lightweight.
meriyah
What's this?
This is my retirement project. I'm playing around and porting private code to public code. This is breaking ground and none of this things have been done before.
Oh! It's a parser. It is what Cherow should have been :)
- Module approach
- Zero backtracking
- Reduced memory usage
- No lookahead
- 100% spec compat
And what's make it unique:
- It fails on all edge cases (V8, Acorn, Cherow and others doesn't fail on this cases)
- Broke free from the regular parsing approach (more freedom and control)
- Fails on cases you never thought was possible
- Super fast
When will it be released
I'm not sure. It's just a playground. So maybe it will never be released?
Performance
Well. It's beat the hell out of Cherow and uses less memory. They can't be compared :)
TODO
- Tweak and play around with performance
- JS Next
WARNING!! WARNING!!!
Every part of this code is dependent of each other, and any adjustments of the code will include a huge risk to screw up the bitmasks. If one 0 or 1 is set wrong, thousands of tests will break. Lucky there exist 60k tests!!