text: const createToken = require('../../../../create-token');
  const symbols = require('../../../../symbols');
  const lelPromise = require('../../../../util/lel-promise');
  const lelPromiseAll = require('../../../../util/lel-promise-all');
  
  module.exports = {
    'math-sin': (evaluateExpr, scope, expr) =>
      lelPromise((resolve, reject) => {
        return evaluateExpr(scope, expr[1]).then(number => {
          if (number.type !== symbols.NUMBER) {
            return reject(new Error(`math-sin only operates on NUMBER type`));
          }
          return resolve(createToken(symbols.NUMBER, Math.sin(number.value)))
        });
      }),
    'math-cos': (evaluateExpr, scope, expr) =>
      lelPromise((resolve, reject) => {
        return evaluateExpr(scope, expr[1]).then(number => {
          if (number.type !== symbols.NUMBER) {
            return reject(new Error(`math-cos only operates on NUMBER type`));
          }
          return resolve(createToken(symbols.NUMBER, Math.cos(number.value)))
        });
      })
  };
  