"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = identity;
var _linear = require("./linear.js");
var _number = _interopRequireDefault(require("./number.js"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
function identity(domain) {
  var unknown;
  function scale(x) {
    return x == null || isNaN(x = +x) ? unknown : x;
  }
  scale.invert = scale;
  scale.domain = scale.range = function (_) {
    return arguments.length ? (domain = Array.from(_, _number.default), scale) : domain.slice();
  };
  scale.unknown = function (_) {
    return arguments.length ? (unknown = _, scale) : unknown;
  };
  scale.copy = function () {
    return identity(domain).unknown(unknown);
  };
  domain = arguments.length ? Array.from(domain, _number.default) : [0, 1];
  return (0, _linear.linearish)(scale);
}