40 lines
1.3 KiB
JavaScript
40 lines
1.3 KiB
JavaScript
import createRBTree from "functional-red-black-tree";
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import { inspect } from "node:util";
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export class RBTreeWrapper {
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constructor(tree) {
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this.tree = tree;
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}
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// pretty print to console
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[inspect.custom](depth, options, inspect) {
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const entries = [];
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this.tree.forEach((key,val) => {entries.push(`${inspect(key)} => ${inspect(val)}`);});
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return `RBTree(${this.tree.length}) {${entries.join(', ')}}`;
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}
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}
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// (a -> a -> Int) -> Set(a)
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export const emptySet = compareFn => new RBTreeWrapper(createRBTree((x, y) => compareFn(x)(y)));
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export const has = set => key => set.tree.get(key) === true;
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export const add = set => key => set.tree.get(key) === true ? set : new RBTreeWrapper(set.tree.insert(key, true));
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export const remove = set => key => new RBTreeWrapper(set.tree.remove(key));
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export const length = set => set.tree.length;
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export const first = set => set.tree.begin;
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export const last = set => set.tree.end;
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// test if iterator is 'done', and if not, get element and advance iterator.
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export const read = iter => ifNotDone => ifDone => {
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if (iter !== undefined && iter.valid) {
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return ifNotDone(iter.key)(iter.clone().next());
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}
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else {
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return ifDone();
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}
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};
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export const forEach = set => fn => {
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set.tree.forEach(key => { fn(key); });
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};
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