arith2js – Calculator Transpiler with Scope Analysis

1.0.0 verified Fri May 01 auth: no javascript

A transpiler that converts calculator expressions (supporting complex numbers, min/max operators, variables, and print statements) into executable JavaScript code. Built on jison and extended from a basic arithmetic calculator, version 1.0.0 adds scope analysis to enforce variable declaration before use, reference semantics for complex objects, and comma-separated expression sequences. Key differentiators: full complex arithmetic transpilation, meticulous error reporting with line/column, and avoidance of primitive method calls via explicit Complex() wrapping.

Common errors

error SyntaxError: Unexpected token, expected ";" ↓

cause Missing semicolon between consecutive expressions.

fix

Add semicolons: e.g., 'a=1; b=2;' instead of 'a=1 b=2;'.

error ReferenceError: $x is not defined ↓

cause Using a variable that was not declared (no prior assignment).

fix

Assign a value to the variable before use: e.g., '$x = 5; print($x);'.

error TypeError: Complex(...).sub is not a function ↓

cause Using an older version (<1.0.0) that did not wrap primitives in Complex().

fix

Upgrade to arith2js-calculator@1.0.0 or later.

error Error: Line 1, col 10: Variable 'y' used before declaration ↓

cause Referencing a variable that has not been assigned earlier in the input.

fix

Declare the variable before its first use: e.g., 'y=1; print(y);'.

Warnings

gotcha Package is ESM-only; using require() will throw ERR_REQUIRE_ESM. ↓

fix Use dynamic import() or set "type": "module" in package.json.

deprecated The direct use of Complex methods on primitives (e.g., (4-2).sub()) is no longer supported; always wrap in Complex(). ↓

fix Upgrade to >=1.0.0 to avoid primitive method call errors.

gotcha Variables use reference semantics for complex numbers; mutations through aliases affect the original. ↓

fix Use explicit cloning (e.g., Complex($a).add(0)) if copy semantics are needed.

gotcha Variable names must be prefixed with $ in the generated code, but the parser accepts unprefixed declarations. ↓

fix Declare variables without $ in the input; the transpiler adds the prefix automatically.

breaking The transpile function now throws on undeclared variable usage; previously it would silently generate possibly broken code. ↓

fix Ensure all variables are declared with an assignment before use.

Install

npm install arith2js-calculator

yarn add arith2js-calculator

pnpm add arith2js-calculator

Imports

transpile

wrong

const { transpile } = require('arith2js-calculator')

correct

import { transpile } from 'arith2js-calculator'

Package is ESM-only; CommonJS require will fail with ERR_REQUIRE_ESM.

arith2js

wrong

import { arith2js } from 'arith2js-calculator'

correct

import arith2js from 'arith2js-calculator'

Default export is the transpiler function; named export does not exist.

Complex

wrong

import Complex from 'arith2js-calculator'

correct

import { Complex } from 'arith2js-calculator'

Complex is a named export, not default.

Quickstart

Transpile a complex expression with variables and print, then evaluate the generated JS.

import arith2js from 'arith2js-calculator';

const expr = 'a=2+3i; b=4-1i; print(a*b);';
try {
  const jsCode = arith2js(expr);
  console.log('Generated JS:');
  console.log(jsCode);
  // Evaluate the generated code (requires Complex class in scope)
  const { Complex } = await import('arith2js-calculator');
  const evalResult = eval(jsCode);
  console.log('Result:', evalResult);
} catch (err) {
  console.error('Transpilation error:', err.message);
}