https://github.com/JexCheng/regulex

:construction: Regular Expression Excited!
https://github.com/JexCheng/regulex

diagram javascript regex regexp regular-expression regulex typescript

Last synced: about 18 hours ago
JSON representation

:construction: Regular Expression Excited!

• Host: GitHub
• URL: https://github.com/JexCheng/regulex
• Owner: CJex
• License: mit
• Created: 2014-05-05T02:40:52.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2022-07-12T09:37:03.000Z (over 2 years ago)
• Last Synced: 2024-12-23T06:39:51.212Z (4 days ago)
• Topics: diagram, javascript, regex, regexp, regular-expression, regulex, typescript
• Language: TypeScript
• Homepage: https://jex.im/regulex/
• Size: 407 KB
• Stars: 5,721
• Watchers: 166
• Forks: 757
• Open Issues: 22
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# Regulex

[Regulex](https://jex.im/regulex/) is a JavaScript Regular Expression Parser & Visualizer.

Try it now: 

**This project is under reconstruction!**

### Features

- Written in pure JavaScript. No backend required.

- You can embed the graph on you own site through HTML iframe element.

- Detailed error message. In most cases it can point out the precise syntax error position.

- No support for octal escape. Yes it is a feature! ECMAScript strict mode doesn't allow octal escape in string, but many browsers still allow octal escape in regex. In regulex, DecimalEscape will always be treated as back reference. If the back reference is invalid, e.g. `/\1/`, `/(\1)/`, `/(a)\2/`, or DecimalEscape appears in charset（because in this case it can't be explained as back reference, e.g. `/(ab)[\1]/`, Regulex will always throw an error.

### Install for Node.js

```

npm install regulex

```

### Local Build for Browser

This command will generate bundle `dist/regulex.js` for browser side:

```bash

git checkout legacy

npm install -g requirejs

r.js -o build-config.js

```

### API

#### Parse to AST

```javascript

var parse = require("regulex").parse;

var re = /var\s+([a-zA-Z_]\w*);/ ;

console.log(parse(re.source));

```

#### Visualize

```javascript

var parse = require("regulex").parse;

var visualize = require("regulex").visualize;

var Raphael = require('regulex').Raphael;

var re = /var\s+([a-zA-Z_]\w*);/;

var paper = Raphael("yourSvgContainerId", 0, 0);

try {

  visualize(parse(re.source), getRegexFlags(re), paper);

} catch(e) {

  if (e instanceof parse.RegexSyntaxError) {

    logError(re, e);

  } else {

    throw e;

  }

}

function logError(re, err) {

  var msg = ["Error:" + err.message, ""];

  if (typeof err.lastIndex === "number") {

    msg.push(re);

    msg.push(new Array(err.lastIndex).join("-") + "^");

  }

  console.log(msg.join("\n"));

}

function getRegexFlags(re) {

  var flags = "";

  flags += re.ignoreCase ? "i" : "";

  flags += re.global ? "g" : "";

  flags += re.multiline ? "m" : "";

  return flags;

}

```