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Getting Started

Installation​

npm install @taioncom/taion-expression

Quick Start​

import { evaluateExpression } from '@taioncom/taion-expression';

const result = evaluateExpression('2 + 3 * 4');

if (result.success) {
  console.log(result.result); // 14
}

Using with Context​

Pass variables to expressions through a context object:

import { evaluateExpression } from '@taioncom/taion-expression';

const context = {
  user: { name: 'Alice', age: 25 },
  threshold: 18,
};

const result = evaluateExpression(
  'user.age >= threshold ? "Adult" : "Minor"',
  context
);

console.log(result.result); // "Adult"

Result Types​

Every call to evaluateExpression returns a discriminated union -- either a success or a failure:

const result = evaluateExpression('1 + 2');

if (result.success) {
  // result.result contains the value
  console.log(result.result); // 3
} else {
  // result.error contains the Error object
  // result.errorCode contains a machine-readable code like "PARSE_ERROR"
  console.error(result.errorCode, result.error.message);
}

Safe Evaluation​

If you prefer null on error instead of checking success, use safeEvaluateExpression:

import { safeEvaluateExpression } from '@taioncom/taion-expression';

const value = safeEvaluateExpression('2 + 3');
console.log(value); // 5

const bad = safeEvaluateExpression('1 + / 2');
console.log(bad); // null

CommonJS Usage​

The library supports both ESM and CommonJS:

const { evaluateExpression } = require('@taioncom/taion-expression');

const result = evaluateExpression('10 % 3');
console.log(result.result); // 1

Next Steps​