static/identifier-set.ts

// Copyright (c) 2022, Compiler Explorer Authors
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export class IdentifierSet {
    private readonly items: Map<number, boolean> = new Map();

    public add(id: number): void {
        this.items.set(id, true);
    }

    public remove(id: number): void {
        this.items.delete(id);
    }

    public next(): number {
        for (let i = 1; i < Number.MAX_SAFE_INTEGER; i++) {
            if (!this.items.has(i)) {
                this.add(i);
                return i;
            }
        }
        throw 'Ran out of ids!?';
    }
}