mathjs/src/expression/transform/concat.transform.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'

const errorTransform = require('./error.transform').transform

/**
 * Attach a transform function to math.range
 * Adds a property transform containing the transform function.
 *
 * This transform changed the last `dim` parameter of function concat
 * from one-based to zero based
 */
function factory (type, config, load, typed) {
  const concat = load(require('../../function/matrix/concat'))

  // @see: comment of concat itself
  return typed('concat', {
    '...any': function (args) {
      // change last argument from one-based to zero-based
      const lastIndex = args.length - 1
      const last = args[lastIndex]
      if (type.isNumber(last)) {
        args[lastIndex] = last - 1
      } else if (type.isBigNumber(last)) {
        args[lastIndex] = last.minus(1)
      }

      try {
        return concat.apply(null, args)
      } catch (err) {
        throw errorTransform(err)
      }
    }
  })
}

exports.name = 'concat'
exports.path = 'expression.transform'
exports.factory = factory