mathsteps-experimental-fork/dist/cjs/lib/checks/resolvesToConstant.js

Step by step math solutions. Experimental Fork

'use strict';

const index = require('../node/index.js');

// Returns true if the node is a constant or can eventually be resolved to
// a constant.
// e.g. 2, 2+4, (2+4)^2 would all return true. x + 4 would return false
function resolvesToConstant(node) {
  if (index.default.Type.isOperator(node) || index.default.Type.isFunction(node))
    return node.args.every(child => resolvesToConstant(child))

  else if (index.default.Type.isConstant(node, true))
    return true

  else if (index.default.Type.isSymbol(node))
    return false

  else if (index.default.Type.isUnaryMinus(node))
    return resolvesToConstant(node.args[0])

  else
    throw new Error(`Unsupported node type: ${node.type}`)
}

module.exports = resolvesToConstant;