Logical Expression Parser (Fork)

This is a logical expression parser for JavaScript, it can parse a logical expression into a AST object and evaluates the result using your token checking function.

Supported logical operators

1. OR
2. AND
3. () Parentheses

How it works

1. The parser parse and tokenize the expression, for example one of your function requires REGISTED AND (SPECIAL OR INVITED)
2. Parser then will pass REGISTED, SPECIAL and INVITED into your token checking function to get a boolean result
3. Finaly the parser will evaluates the final result

Example

const LEP = require('@jeanbenitez/lep');

const requirements = 'REGISTED AND (SPECIAL OR INVITED)';
const listA = ['REGISTED', 'INVITED'];
const listB = ['SPECIAL', 'EXPERT'];

const resultA = LEP.parse(requirements, t => listA.includes(t));
const resultB = LEP.parse(requirements, t => listB.includes(t));
console.log({ resultA, resultB });
// { resultA: true, resultB: false }

// Getting AST only
const ast = LEP.ast(requirements);
console.log({ ast });
/*
  {
    ast: ExpNode {
      op: 'AND',
      left: ExpNode {
        op: 'LITERAL',
        literal: 'REGISTED'
      },
      right: ExpNode {
        op: 'OR',
        left: [ExpNode],
        right: [ExpNode]
      }
    }
  }
*/