fcr-core/lib-es/utilities/collection.js

Core APIs for building online scenes

import "core-js/modules/es.array.push.js";
export const iterateMap = (map, processors) => {
  const onFilter = processors?.onFilter || (() => true);
  const {
    onMap,
    onReduce
  } = processors || {};
  const list = [];
  let prev = undefined;
  for (const [k, v] of map.entries()) {
    if (onFilter(k, v)) {
      if (onMap) list.push(onMap(k, v));
      if (onReduce) prev = onReduce(prev, k, v);
    }
  }
  return {
    list,
    prev
  };
};
export const iterateSet = (map, processors) => {
  const onFilter = processors?.onFilter || (() => true);
  const {
    onMap,
    onReduce
  } = processors || {};
  const list = [];
  let prev = undefined;
  for (const item of map.values()) {
    if (onFilter(item)) {
      if (onMap) list.push(onMap(item));
      if (onReduce) prev = onReduce(prev, item);
    }
  }
  return {
    list,
    prev
  };
};

/**
 * expand a key-value map to a structure
 * .e.g. { 'a.b.c': 1 } => { a: { b: { c: 1 } } }
 * @param kvMap
 */
export const convertToStructure = kvMap => {
  const result = {};
  for (const key in kvMap) {
    const keys = key.split('.');
    let temp = result;
    for (let i = 0; i < keys.length; i++) {
      const k = keys[i];
      if (i === keys.length - 1) {
        temp[k] = kvMap[key];
      } else {
        if (!temp[k]) {
          temp[k] = {};
        }
        temp = temp[k];
      }
    }
  }
  return result;
};