mathjs/lib/function/string/print.js

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser with support for symbolic computation, comes with a large set of built-in functions and constants, and offers an integrated solution to work with dif

'use strict';

var isString = require('../../utils/string').isString;

var format = require('../../utils/string').format;

function factory(type, config, load, typed) {
  /**
   * Interpolate values into a string template.
   *
   * Syntax:
   *
   *     math.print(template, values)
   *     math.print(template, values, precision)
   *     math.print(template, values, options)
   *
   * Example usage:
   *
   *     // the following outputs: 'Lucy is 5 years old'
   *     math.print('Lucy is $age years old', {age: 5})
   *
   *     // the following outputs: 'The value of pi is 3.141592654'
   *     math.print('The value of pi is $pi', {pi: math.pi}, 10)
   *
   *     // the following outputs: 'hello Mary! The date is 2013-03-23'
   *     math.print('Hello $user.name! The date is $date', {
   *       user: {
   *         name: 'Mary',
   *       },
   *       date: new Date(2013, 2, 23).toISOString().substring(0, 10)
   *     })
   *
   *     // the following outputs: 'My favorite fruits are apples and bananas !'
   *     math.print('My favorite fruits are $0 and $1 !', [
   *       'apples',
   *       'bananas'
   *     ])
   *
   * See also:
   *
   *     format
   *
   * @param {string} template           A string containing variable placeholders.
   * @param {Object | Array | Matrix}   values An object or array containing variables
   *                                    which will be filled in in the template.
   * @param {number | Object} [options] Formatting options,
   *                                    or the number of digits to format numbers.
   *                                    See function math.format for a description
   *                                    of all options.
   * @return {string} Interpolated string
   */
  var print = typed('print', {
    // note: Matrix will be converted automatically to an Array
    'string, Object | Array': _print,
    'string, Object | Array, number | Object': _print
  });
  print.toTex = undefined; // use default template

  return print;
}
/**
 * Interpolate values into a string template.
 * @param {string} template
 * @param {Object} values
 * @param {number | Object} [options]
 * @returns {string} Interpolated string
 * @private
 */


function _print(template, values, options) {
  return template.replace(/\$([\w.]+)/g, function (original, key) {
    var keys = key.split('.');
    var value = values[keys.shift()];

    while (keys.length && value !== undefined) {
      var k = keys.shift();
      value = k ? value[k] : value + '.';
    }

    if (value !== undefined) {
      if (!isString(value)) {
        return format(value, options);
      } else {
        return value;
      }
    }

    return original;
  });
}

exports.name = 'print';
exports.factory = factory;