+ * Defines an own enumerable data property on the provided object with
+ * the provided property key and value.
+ */
+export const defineOwnDataProperty = (O, P, V) =>
+ defineProperty(
+ O,
+ P,
+ assign(create(null), {
+ configurable: true,
+ enumerable: true,
+ value: V,
+ writable: true,
+ }),
+ );
+
+/**
+ * Defines an own nonenumerable data property on the provided object
+ * with the provided property key and value.
+ */
+export const defineOwnNonenumerableDataProperty = (O, P, V) =>
+ defineProperty(
+ O,
+ P,
+ assign(create(null), {
+ configurable: true,
+ enumerable: false,
+ value: V,
+ writable: true,
+ }),
+ );
+
+/**
+ * Defines an own property on the provided object on the provided
+ * property key using the provided property descriptor.
+ *
+ * ※ This is effectively an alias for `Object.defineProperty`.
+ */
+export const defineOwnProperty = (O, P, Desc) =>
+ defineProperty(O, P, Desc);
+
+/**
+ * Defines own properties on the provided object using the descriptors
+ * on the enumerable own properties of the provided additional objects.
+ *
+ * ※ This differs from `Object.defineProperties` in that it can take
+ * multiple source objects.
+ */
+export const defineOwnProperties = (O, ...sources) => {
+ const { length } = sources;
+ for (let k = 0; k < length; ++k) {
+ defineProperties(O, sources[k]);
+ }
+ return O;
+};
+
+/**
+ * Removes the provided property key from the provided object and
+ * returns the object.
+ *
+ * ※ This function differs from `Reflect.deleteProperty` and the
+ * `delete` operator in that it throws if the deletion is
+ * unsuccessful.
+ *
+ * ☡ This function throws if the first argument is not an object.
+ */
+export const deleteOwnProperty = (O, P) => {
+ if (type(O) !== "object") {
+ throw new TypeError(
+ `Piscēs: Tried to set property but provided value was not an object: ${V}`,
+ );
+ } else if (!deleteProperty(O, P)) {
+ throw new TypeError(
+ `Piscēs: Tried to delete property from object but [[Delete]] returned false: ${P}`,
+ );
+ } else {
+ return O;
+ }
+};
+
+/**
+ * Marks the provided object as non·extensible and marks all its
+ * properties as nonconfigurable and (if data properties) nonwritable,
+ * and returns the object.
+ *
+ * ※ This is effectively an alias for `Object.freeze`.
+ */
+export const freeze = (O) => objectFreeze(O);
+
+/**
+ * Returns a new frozen shallow copy of the enumerable own properties
+ * of the provided object, according to the following rules :—
+ *
+ * - For data properties, create a nonconfigurable, nonwritable
+ * property with the same value.
+ *
+ * - For accessor properties, create a nonconfigurable accessor
+ * property with the same getter *and* setter.
+ *
+ * The prototype for the resulting object will be taken from the
+ * `.prototype` property of the provided constructor, or the
+ * `.prototype` of the `.constructor` of the provided object if the
+ * provided constructor is undefined. If the used constructor has a
+ * nonnullish `.[Symbol.species]`, that will be used instead. If the
+ * used constructor or species is nullish or does not have a
+ * `.prototype` property, the prototype is set to null.
+ *
+ * ※ The prototype of the provided object itself is ignored.
+ */
+export const frozenCopy = (O, constructor = O?.constructor) => {
+ if (O == null) {
+ // O is null or undefined.
+ throw new TypeError(
+ "Piscēs: Cannot copy properties of null or undefined.",
+ );
+ } else {
+ // O is not null or undefined.
+ //
+ // (If not provided, the constructor will be the value of getting
+ // the `.constructor` property of O.)
+ const species = constructor?.[SPECIES] ?? constructor;
+ const copy = create(
+ species == null || !("prototype" in species)
+ ? null
+ : species.prototype,
+ );
+ const keys = ownKeys(O);
+ for (let k = 0; k < keys.length; ++k) {
+ const P = keys[k];
+ const Desc = getOwnPropertyDescriptor(O, P);
+ if (Desc.enumerable) {
+ // P is an enumerable property.
+ defineProperty(
+ copy,
+ P,
+ assign(
+ create(null),
+ isAccessorDescriptor(Desc)
+ ? {
+ configurable: false,
+ enumerable: true,
+ get: Desc.get,
+ set: Desc.set,
+ }
+ : {
+ configurable: false,
+ enumerable: true,
+ value: Desc.value,
+ writable: false,
+ },
+ ),
+ );
+ } else {
+ // P is not an enumerable property.
+ /* do nothing */
+ }
+ }
+ return objectPreventExtensions(copy);
+ }
+};
+
+/**
+ * Returns the function on the provided value at the provided property
+ * key.
+ *
+ * ☡ This function throws if the provided property key does not have an
+ * associated value which is callable.
+ */
+export const getMethod = (V, P) => {
+ const func = V[P];
+ if (func == null) {
+ return undefined;
+ } else if (typeof func !== "function") {
+ throw new TypeError(`Piscēs: Method not callable: ${P}`);
+ } else {
+ return func;
+ }
+};
+
+/**
+ * Returns the property descriptor record for the own property with the
+ * provided property key on the provided value, or null if none exists.
+ *
+ * ※ This is effectively an alias for
+ * `Object.getOwnPropertyDescriptor`, but the return value is a proxied
+ * object with null prototype.
+ */
+export const getOwnPropertyDescriptor = (O, P) => {
+ const desc = objectGetOwnPropertyDescriptor(O, P);
+ return desc === UNDEFINED
+ ? UNDEFINED
+ : toPropertyDescriptorRecord(desc);
+};
+
+/**
+ * Returns the property descriptors for the own properties on the
+ * provided value.
+ *
+ * ※ This is effectively an alias for
+ * `Object.getOwnPropertyDescriptors`, but the values on the resulting
+ * object are proxied objects with null prototypes.
+ */
+export const getOwnPropertyDescriptors = (O) => {
+ const obj = toObject(O);
+ const keys = ownKeys(obj);
+ const descriptors = {};
+ for (let k = 0; k < keys.length; ++k) {
+ // Iterate over the keys of the provided object and collect its
+ // descriptors.
+ const key = keys[k];
+ defineOwnDataProperty(
+ descriptors,
+ key,
+ getOwnPropertyDescriptor(O, key),
+ );
+ }
+ return descriptors;
+};
+
+/**
+ * Returns an array of own property entries on the provided value,
+ * using the provided receiver if given.
+ */
+export const getOwnPropertyEntries = (O, Receiver = O) => {
+ const obj = toObject(O);
+ const keys = ownKeys(obj);
+ const target = Receiver === UNDEFINED ? obj : toObject(Receiver);
+ const result = createArray(keys.length);
+ for (let k = 0; k < keys.length; ++k) {
+ // Iterate over each key and add the corresponding entry to the
+ // result.
+ const key = keys[k];
+ defineOwnDataProperty(
+ result,
+ k,
+ [key, getOwnPropertyValue(obj, keys[k], target)],
+ );
+ }
+ return result;
+};
+
+/**
+ * Returns an array of own property keys on the provided value.
+ *
+ * ※ This is effectively an alias for `Reflect.ownKeys`, except that
+ * it does not require that the argument be an object.
+ */
+export const getOwnPropertyKeys = (O) => ownKeys(toObject(O));
+
+/**
+ * Returns an array of string‐valued own property keys on the
+ * provided value.
+ *
+ * ☡ This includes both enumerable and non·enumerable properties.
+ *
+ * ※ This is effectively an alias for `Object.getOwnPropertyNames`.
+ */
+export const getOwnPropertyStrings = (O) => getOwnPropertyNames(O);
+
+/**
+ * Returns an array of symbol‐valued own property keys on the
+ * provided value.
+ *
+ * ☡ This includes both enumerable and non·enumerable properties.
+ *
+ * ※ This is effectively an alias for
+ * `Object.getOwnPropertySymbols`.
+ */
+export const getOwnPropertySymbols = (O) =>
+ objectGetOwnPropertySymbols(O);
+
+/**
+ * Returns the value of the provided own property on the provided
+ * value using the provided receiver, or undefined if the provided
+ * property is not an own property on the provided value.
+ *
+ * ※ If the receiver is not provided, it defaults to the provided
+ * value.
+ */
+export const getOwnPropertyValue = (O, P, Receiver = UNDEFINED) => {
+ const obj = toObject(O);
+ const desc = getOwnPropertyDescriptor(O, P);
+ if (desc === UNDEFINED) {
+ // The provided property is not an own property on the provided
+ // value; return undefined.
+ return UNDEFINED;
+ }
+ if (isDataDescriptor(desc)) {
+ // The provided property is a data property; return its value.
+ return desc.value;
+ } else {
+ // The provided property is an accessor property; get its value
+ // using the appropriate receiver.
+ const target = Receiver === UNDEFINED ? obj : toObject(Receiver);
+ return call(desc.get, target, []);
+ }
+};
+
+/**
+ * Returns an array of own property values on the provided value, using
+ * the provided receiver if given.
+ */
+export const getOwnPropertyValues = (O, Receiver = O) => {
+ const obj = toObject(O);
+ const keys = ownKeys(obj);
+ const target = Receiver === UNDEFINED ? obj : toObject(Receiver);
+ const result = createArray(keys.length);
+ for (let k = 0; k < keys.length; ++k) {
+ // Iterate over each key and collect the values.
+ defineOwnDataProperty(
+ result,
+ k,
+ getOwnPropertyValue(obj, keys[k], target),
+ );
+ }
+ return result;
+};
+
+/**
+ * Returns the value of the provided property key on the provided
+ * value.
+ *
+ * ※ This is effectively an alias for `Reflect.get`, except that it
+ * does not require that the argument be an object.
+ */
+export const getPropertyValue = (O, P, Receiver = O) =>
+ get(toObject(O), P, Receiver);
+
+/**
+ * Returns the prototype of the provided value.
+ *
+ * ※ This is effectively an alias for `Object.getPrototypeOf`.
+ */
+export const getPrototype = (O) => getPrototypeOf(O);
+
+/**
+ * Returns whether the provided value has an own property with the
+ * provided property key.
+ *
+ * ※ This is effectively an alias for `Object.hasOwn`.
+ */
+export const hasOwnProperty = (O, P) => hasOwn(O, P);
+
+/**
+ * Returns whether the provided property key exists on the provided
+ * value.
+ *
+ * ※ This is effectively an alias for `Reflect.has`, except that it
+ * does not require that the argument be an object.
+ *
+ * ※ This includes properties present on the prototype chain.
+ */
+export const hasProperty = (O, P) => has(toObject(O), P);
+
+/** Returns whether the provided value is an arraylike object. */
+export const isArraylikeObject = ($) => {
+ if (type($) !== "object") {
+ return false;
+ } else {
+ try {
+ lengthOfArraylike($); // throws if not arraylike
+ return true;
+ } catch {
+ return false;
+ }
+ }
+};
+
+/**
+ * Returns whether the provided value is spreadable during array
+ * concatenation.
+ *
+ * This is also used to determine which things should be treated as
+ * collections.
+ */
+export const isConcatSpreadableObject = ($) => {
+ if (type($) !== "object") {
+ // The provided value is not an object.
+ return false;
+ } else {
+ // The provided value is an object.
+ const spreadable = $[IS_CONCAT_SPREADABLE];
+ return spreadable !== UNDEFINED ? !!spreadable : isArray($);
+ }
+};
+
+/**
+ * Returns whether the provided value is an extensible object.
+ *
+ * ※ This function returns false for nonobjects.
+ *
+ * ※ This is effectively an alias for `Object.isExtensible`.
+ */
+export const isExtensibleObject = (O) => isExtensible(O);
+
+export const {
+ /**
+ * Returns whether the provided value is a property descriptor record
+ * as created by `toPropertyDescriptor`.
+ *
+ * ※ This function is provided to enable inspection of whether an
+ * object uses the property descriptor record proxy implementation,
+ * not as a general test of whether an object satisfies the
+ * requirements for property descriptors. In most cases, a more
+ * specific test, like `isAccessorDescriptor`, `isDataDescriptor`, or
+ * `isGenericDescriptor`, is preferrable.
+ */
+ isPropertyDescriptorRecord,
+
+ /**
+ * Converts the provided value to a property descriptor record.
+ *
+ * ※ The prototype of a property descriptor record is always `null`.
+ *
+ * ※ Actually constructing a property descriptor object using this
+ * class is only necessary if you need strict guarantees about the
+ * types of its properties; the resulting object is proxied to ensure
+ * the types match what one would expect from composing
+ * FromPropertyDescriptor and ToPropertyDescriptor in the Ecmascript
+ * specification.
+ */
+ toPropertyDescriptorRecord,
+} = (() => {
+ const proxyConstructor = Proxy;
+ const { add: weakSetAdd, has: weakSetHas } = WeakSet.prototype;
+ const propertyDescriptorRecords = new WeakSet();
+ const coercePropertyDescriptorValue = (P, V) => {
+ switch (P) {
+ case "configurable":
+ case "enumerable":
+ case "writable":
+ return !!V;
+ case "value":
+ return V;
+ case "get":
+ if (V !== undefined && typeof V !== "function") {
+ throw new TypeError(
+ "Piscēs: Getters must be callable.",
+ );
+ } else {
+ return V;
+ }
+ case "set":
+ if (V !== undefined && typeof V !== "function") {
+ throw new TypeError(
+ "Piscēs: Setters must be callable.",
+ );
+ } else {
+ return V;
+ }
+ default:
+ return V;
+ }
+ };
+ const propertyDescriptorProxyHandler = objectFreeze(
+ assign(
+ create(null),
+ {
+ defineProperty(O, P, Desc) {
+ if (
+ P === "configurable" || P === "enumerable" ||
+ P === "writable" || P === "value" ||
+ P === "get" || P === "set"
+ ) {
+ // P is a property descriptor attribute.
+ const desc = assign(objectCreate(null), Desc);
+ if ("get" in desc || "set" in desc) {
+ // Desc is an accessor property descriptor.
+ throw new TypeError(
+ "Piscēs: Property descriptor attributes must be data properties.",
+ );
+ } else if ("value" in desc || !(P in O)) {
+ // Desc has a value or P does not already exist on O.
+ desc.value = coercePropertyDescriptorValue(
+ P,
+ desc.value,
+ );
+ } else {
+ // Desc is not an accessor property descriptor and has no
+ // value, but an existing value is present on O.
+ /* do nothing */
+ }
+ const isAccessorDescriptor = "get" === P || "set" === P ||
+ "get" in O || "set" in O;
+ const isDataDescriptor = "value" === P ||
+ "writable" === P ||
+ "value" in O || "writable" in O;
+ if (isAccessorDescriptor && isDataDescriptor) {
+ // Both accessor and data attributes will be present on O
+ // after defining P.
+ throw new TypeError(
+ "Piscēs: Property descriptors cannot specify both accessor and data attributes.",
+ );
+ } else {
+ // P can be safely defined on O.
+ return reflectDefineProperty(O, P, desc);
+ }
+ } else {
+ // P is not a property descriptor attribute.
+ return reflectDefineProperty(O, P, Desc);
+ }
+ },
+ setPrototypeOf(O, V) {
+ if (V !== null) {
+ // V is not the property descriptor prototype.
+ return false;
+ } else {
+ // V is the property descriptor prototype.
+ return reflectSetPrototypeOf(O, V);
+ }
+ },
+ },
+ ),
+ );
+
+ return {
+ isPropertyDescriptorRecord: ($) =>
+ call(weakSetHas, propertyDescriptorRecords, [$]),
+ toPropertyDescriptorRecord: (Obj) => {
+ if (type(Obj) !== "object") {
Lady’s Gitweb / Pisces / blobdiff