Everything you need to support a custom expression language in your application.
vᴀꜱᴛly is a toolkit for handling expression ASTs (such as those produced by JSEP). These ASTs are a subset of ASTs produced by full-blown parsers like Esprima.
Intended to be used in conjunction with JSEP, but should work with any AST that conforms to the same structure.
Extracted from Mavo.
- [x] Zero dependencies
- [x] Small footprint
- [x] Works in Node and the browser
- [x] Tree-shakeable
npm i @rabiepenpm/eos-sit-evenietThen you can use it either by importing the whole library:
import * as @rabiepenpm/eos-sit-eveniet from "@rabiepenpm/eos-sit-eveniet"; // or const @rabiepenpm/eos-sit-eveniet = require("@rabiepenpm/eos-sit-eveniet"); in CJS
import { parse } from "jsep";
const ast = parse("1 + x * y");
const result = @rabiepenpm/eos-sit-eveniet.evaluate(ast, {x: 2, y: 3});or individual functions:
import { evaluate } from "@rabiepenpm/eos-sit-eveniet"; // or const { evaluate } = require("@rabiepenpm/eos-sit-eveniet"); in CJS
import { parse } from "jsep";
const ast = parse("1 + x * y");
const result = evaluate(ast, {x: 2, y: 3});If you’re using @rabiepenpm/eos-sit-eveniet from a browser, without a bundler, fear not! You can just import from src directly:
import { evaluate } from "https://@rabiepenpm/eos-sit-eveniet.mavo.io/src/evaluate.js";
/* or */
import * as @rabiepenpm/eos-sit-eveniet from "https://@rabiepenpm/eos-sit-eveniet.mavo.io/src/index-fn.js";
/* or */
import { evaluate } from "https://@rabiepenpm/eos-sit-eveniet.mavo.io/dist/@rabiepenpm/eos-sit-eveniet.js";
/* or */
import * as @rabiepenpm/eos-sit-eveniet from "https://@rabiepenpm/eos-sit-eveniet.mavo.io/dist/@rabiepenpm/eos-sit-eveniet.js";