zulip/static/js/fold_dict.ts

79 lines
1.9 KiB
TypeScript

/*
Use this class to manage keys where you don't care
about case (i.e. case-insensitive).
Keys for FoldDict should be strings. We "fold" all
casings of "alice" (e.g. "ALICE", "Alice", "ALIce", etc.)
to "alice" as the key.
Examples of case-insensitive data in Zulip are:
- emails
- stream names
- topics
- etc.
*/
type KeyValue<V> = { k: string; v: V };
export class FoldDict<V> {
private _items: Map<string, KeyValue<V>> = new Map();
get(key: string): V | undefined {
const mapping = this._items.get(this._munge(key));
if (mapping === undefined) {
return undefined;
}
return mapping.v;
}
set(key: string, value: V): V {
this._items.set(this._munge(key), {k: key, v: value});
return value;
}
has(key: string): boolean {
return this._items.has(this._munge(key));
}
del(key: string): void {
this._items.delete(this._munge(key));
}
keys(): string[] {
return [...this._items.values()].map(({k}) => k);
}
values(): V[] {
return [...this._items.values()].map(({v}) => v);
}
items(): [string, V][] {
return [...this._items.values()].map(({k, v}) => [k, v]);
}
num_items(): number {
return this._items.size;
}
is_empty(): boolean {
return this._items.size === 0;
}
each(f: (v: V, k?: string) => void): void {
this._items.forEach(({k, v}) => f(v, k));
}
clear(): void {
this._items.clear();
}
// Handle case-folding of keys and the empty string.
private _munge(key: string): string | undefined {
if (key === undefined) {
blueslip.error("Tried to call a FoldDict method with an undefined key.");
return undefined;
}
return key.toString().toLowerCase();
}
}