59 lines
1.2 KiB
JavaScript
59 lines
1.2 KiB
JavaScript
import { Item_Unresolvable } from '@efforting.tech/errors';
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class Abstract_Resolver {
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resolve(item) {
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const handler = this.resolve_handler(item);
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if (!handler) {
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throw new Item_Unresolvable({ resolver: this, item });
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}
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return handler({ resolver: this, item });
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}
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}
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class Chained_Resolver extends Abstract_Resolver {
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constructor(chain_links) {
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super();
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Object.assign(this, { chain_links });
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}
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resolve_handler(item) {
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const { chain_links } = this;
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for (const link of chain_links) {
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const handler = link.resolve_handler(item);
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if (handler) {
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return handler;
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}
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}
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}
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}
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class Mapping_Resolver {
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constructor(rules=new Map(), key_function=null) {
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Object.assign(this, { rules, key_function });
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}
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resolve_handler(item) {
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const { key_function, rules } = this;
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const key = key_function ? key_function(item) : item;
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return rules.get(key);
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}
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}
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const vr = new Mapping_Resolver();
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const tr = new Mapping_Resolver(new Map(), item => typeof item);
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const cr = new Chained_Resolver([vr, tr]);
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vr.rules.set('HELLO', () => 'WORLD');
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tr.rules.set('string', () => 'World');
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console.log(cr.resolve('HELLO'));
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console.log(cr.resolve('hello'));
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console.log(cr.resolve(123));
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