83 lines
3.8 KiB
JavaScript
83 lines
3.8 KiB
JavaScript
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"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.softMixProtos = exports.proxyMix = exports.getIngredientWithProp = void 0;
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const util_1 = require("./util");
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/**
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* Finds the ingredient with the given prop, searching in reverse order and breadth-first if searching ingredient
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* prototypes is required.
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*/
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const getIngredientWithProp = (prop, ingredients) => {
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const protoChains = ingredients.map(ingredient => util_1.protoChain(ingredient));
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// since we search breadth-first, we need to keep track of our depth in the prototype chains
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let protoDepth = 0;
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// not all prototype chains are the same depth, so this remains true as long as at least one of the ingredients'
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// prototype chains has an object at this depth
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let protosAreLeftToSearch = true;
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while (protosAreLeftToSearch) {
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// with the start of each horizontal slice, we assume this is the one that's deeper than any of the proto chains
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protosAreLeftToSearch = false;
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// scan through the ingredients right to left
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for (let i = ingredients.length - 1; i >= 0; i--) {
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const searchTarget = protoChains[i][protoDepth];
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if (searchTarget !== undefined && searchTarget !== null) {
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// if we find something, this is proof that this horizontal slice potentially more objects to search
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protosAreLeftToSearch = true;
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// eureka, we found it
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if (Object.getOwnPropertyDescriptor(searchTarget, prop) != undefined) {
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return protoChains[i][0];
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}
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}
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}
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protoDepth++;
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}
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return undefined;
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};
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exports.getIngredientWithProp = getIngredientWithProp;
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/**
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* "Mixes" ingredients by wrapping them in a Proxy. The optional prototype argument allows the mixed object to sit
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* downstream of an existing prototype chain. Note that "properties" cannot be added, deleted, or modified.
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*/
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const proxyMix = (ingredients, prototype = Object.prototype) => new Proxy({}, {
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getPrototypeOf() {
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return prototype;
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},
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setPrototypeOf() {
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throw Error('Cannot set prototype of Proxies created by ts-mixer');
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},
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getOwnPropertyDescriptor(_, prop) {
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return Object.getOwnPropertyDescriptor(exports.getIngredientWithProp(prop, ingredients) || {}, prop);
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},
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defineProperty() {
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throw new Error('Cannot define new properties on Proxies created by ts-mixer');
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},
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has(_, prop) {
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return exports.getIngredientWithProp(prop, ingredients) !== undefined || prototype[prop] !== undefined;
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},
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get(_, prop) {
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return (exports.getIngredientWithProp(prop, ingredients) || prototype)[prop];
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},
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set(_, prop, val) {
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const ingredientWithProp = exports.getIngredientWithProp(prop, ingredients);
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if (ingredientWithProp === undefined)
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throw new Error('Cannot set new properties on Proxies created by ts-mixer');
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ingredientWithProp[prop] = val;
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return true;
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},
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deleteProperty() {
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throw new Error('Cannot delete properties on Proxies created by ts-mixer');
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},
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ownKeys() {
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return ingredients
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.map(Object.getOwnPropertyNames)
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.reduce((prev, curr) => curr.concat(prev.filter(key => curr.indexOf(key) < 0)));
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},
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});
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exports.proxyMix = proxyMix;
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/**
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* Creates a new proxy-prototype object that is a "soft" mixture of the given prototypes. The mixing is achieved by
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* proxying all property access to the ingredients. This is not ES5 compatible and less performant. However, any
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* changes made to the source prototypes will be reflected in the proxy-prototype, which may be desirable.
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*/
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const softMixProtos = (ingredients, constructor) => exports.proxyMix([...ingredients, { constructor }]);
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exports.softMixProtos = softMixProtos;
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