ecsy/src/Types.js

Entity Component System in JS

export const copyValue = (src) => src;

export const cloneValue = (src) => src;

export const copyArray = (src, dest) => {
  if (!src) {
    return src;
  }

  if (!dest) {
    return src.slice();
  }

  dest.length = 0;

  for (let i = 0; i < src.length; i++) {
    dest.push(src[i]);
  }

  return dest;
};

export const cloneArray = (src) => src && src.slice();

export const copyJSON = (src) => JSON.parse(JSON.stringify(src));

export const cloneJSON = (src) => JSON.parse(JSON.stringify(src));

export const copyCopyable = (src, dest) => {
  if (!src) {
    return src;
  }

  if (!dest) {
    return src.clone();
  }

  return dest.copy(src);
};

export const cloneClonable = (src) => src && src.clone();

export function createType(typeDefinition) {
  var mandatoryProperties = ["name", "default", "copy", "clone"];

  var undefinedProperties = mandatoryProperties.filter((p) => {
    return !typeDefinition.hasOwnProperty(p);
  });

  if (undefinedProperties.length > 0) {
    throw new Error(
      `createType expects a type definition with the following properties: ${undefinedProperties.join(
        ", "
      )}`
    );
  }

  typeDefinition.isType = true;

  return typeDefinition;
}

/**
 * Standard types
 */
export const Types = {
  Number: createType({
    name: "Number",
    default: 0,
    copy: copyValue,
    clone: cloneValue,
  }),

  Boolean: createType({
    name: "Boolean",
    default: false,
    copy: copyValue,
    clone: cloneValue,
  }),

  String: createType({
    name: "String",
    default: "",
    copy: copyValue,
    clone: cloneValue,
  }),

  Array: createType({
    name: "Array",
    default: [],
    copy: copyArray,
    clone: cloneArray,
  }),

  Ref: createType({
    name: "Ref",
    default: undefined,
    copy: copyValue,
    clone: cloneValue,
  }),

  JSON: createType({
    name: "JSON",
    default: null,
    copy: copyJSON,
    clone: cloneJSON,
  }),
};