https://github.com/mavoweb/vastly

Everything you need to support a custom formula language
https://github.com/mavoweb/vastly

ast expressions formulas parsing

Last synced: about 3 hours ago
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Everything you need to support a custom formula language

• Host: GitHub
• URL: https://github.com/mavoweb/vastly
• Owner: mavoweb
• License: mit
• Created: 2023-10-26T20:21:46.000Z (about 1 year ago)
• Default Branch: main
• Last Pushed: 2024-03-14T22:18:32.000Z (8 months ago)
• Last Synced: 2024-04-14T07:56:05.026Z (7 months ago)
• Topics: ast, expressions, formulas, parsing
• Language: JavaScript
• Homepage: https://vastly.mavo.io
• Size: 169 KB
• Stars: 13
• Watchers: 4
• Forks: 1
• Open Issues: 5
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        


# vᴀꜱᴛly

Everything you need to support a custom expression language in your application.

## What is this?

vᴀꜱᴛly is a toolkit for handling expression ASTs (such as those produced by [JSEP](https://ericsmekens.github.io/jsep/)).

These ASTs are a subset of ASTs produced by full-blown parsers like [Esprima](https://esprima.org/).

Intended to be used in conjunction with [JSEP](https://ericsmekens.github.io/jsep/), but should work with any AST that conforms to the same structure.

Extracted from [Mavo](https://mavo.io).

## Features

- [x] Zero dependencies

- [x] Small footprint

- [x] Works in Node and the browser

- [x] Tree-shakeable

## Usage

```sh

npm i vastly

```

Then you can use it either by importing the whole library:

```js

import * as vastly from "vastly"; // or const vastly = require("vastly"); in CJS

import { parse } from "jsep";

const ast = parse("1 + x * y");

const result = vastly.evaluate(ast, {x: 2, y: 3});

```

or individual functions:

```js

import { evaluate } from "vastly"; // or const { evaluate } = require("vastly"); in CJS

import { parse } from "jsep";

const ast = parse("1 + x * y");

const result = evaluate(ast, {x: 2, y: 3});

```

If you’re using vastly from a browser, without a bundler, fear not! You can just import from `src` directly:

```js

import { evaluate } from "https://vastly.mavo.io/src/evaluate.js";

/* or */

import * as vastly from "https://vastly.mavo.io/src/index-fn.js";

/* or */

import { evaluate } from "https://vastly.mavo.io/dist/vastly.js";

/* or */

import * as vastly from "https://vastly.mavo.io/dist/vastly.js";

```

[Full API reference](https://vastly.mavo.io/docs/)

// Create global variable to facilitate experimentation

import * as vastly from "./src/index.js";

globalThis.vastly = vastly;