How to use vega-transforms - 3 common examples

import {aggregate, window} from 'vega-transforms';
import {
  accessor, array, compare, error, field,
  isArray, isObject, isFunction, isRegExp, isString,
  toBoolean, toNumber, toSet, toString
} from 'vega-util';

const Ascending = 'ascending',
      Descending = 'descending',
      AggregateOps = toSet(aggregate.Definition.params[1].values),
      WindowOps = toSet(window.Definition.params[2].values);

export function parser(p) {
  const type = p.array ? 'array' : p.type;
  return TypeParsers[type](p);
}

export const TypeParsers = {
  array: p => {
    const len = p.length,
          name = p.name,
          type = TypeParsers[p.type];

    return value => {
      if (!isArray(value)) {
        error(`Expected array parameter: ${name}.`);
      }

import {extendParams, removeParams} from './util';
import transform from '../transform';
import {window} from 'vega-transforms';
import {extend} from 'vega-util';

const def = extend({}, window.Definition);

def.params = removeParams(def.params, ['ops', 'fields', 'as', 'params']);
def.params = extendParams(def.params, {
  sort: { alias: 'compare' }
});
def.params.push({name: 'measure', type: 'window', proxy: true});

export default transform(def, ['compare', 'frame', 'measure']);

import {aggregate, window} from 'vega-transforms';
import {
  accessor, array, compare, error, field,
  isArray, isObject, isFunction, isRegExp, isString,
  toBoolean, toNumber, toSet, toString
} from 'vega-util';

const Ascending = 'ascending',
      Descending = 'descending',
      AggregateOps = toSet(aggregate.Definition.params[1].values),
      WindowOps = toSet(window.Definition.params[2].values);

export function parser(p) {
  const type = p.array ? 'array' : p.type;
  return TypeParsers[type](p);
}

export const TypeParsers = {
  array: p => {
    const len = p.length,
          name = p.name,
          type = TypeParsers[p.type];

    return value => {
      if (!isArray(value)) {
        error(`Expected array parameter: ${name}.`);