indexable-map
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Built-in JavaScript Map with secondary indexes
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# indexable-map
Built-in JavaScript Map with secondary indexes
## Example
```typescript
import assert from 'node:assert'
import { IndexableMap } from 'indexable-map'
type Person = { age: number; firstName: string; lastName: string }
type Indexes = 'byYoungAge' | 'byOldAge'
const im = new IndexableMap<number, Person, Indexes>(
[
[1, { age: 30, firstName: 'Galina', lastName: 'Ivanova' }],
[2, { age: 59, firstName: 'Zinaida', lastName: 'Petrovna' }],
[3, { age: 17, firstName: 'Stepan', lastName: 'Lukov' }],
[4, { age: 59, firstName: 'Ibragim', lastName: 'Lukov' }],
],
{
indexes: [
{
field: 'age',
filter({ age }) {
return age >= 40
},
name: 'byOldAge',
},
{
field: 'age',
filter({ age }) {
return age < 40
},
name: 'byYoungAge',
},
],
}
)
assert.deepStrictEqual(im.getByIndex('byOldAge', 59), [
{
age: 59,
firstName: 'Zinaida',
lastName: 'Petrovna',
},
{
age: 59,
firstName: 'Ibragim',
lastName: 'Lukov',
},
])
assert.deepStrictEqual(im.getByIndex('byYoungAge', 30),
[{ age: 30, firstName: 'Galina', lastName: 'Ivanova' }])
assert.deepStrictEqual(im.getByIndex('byYoungAge', 17),
[{ age: 17, firstName: 'Stepan', lastName: 'Lukov' }])
assert.deepStrictEqual(im.getByIndex('byYoungAge', 59), [])
assert.deepStrictEqual(im.getByIndex('byOldAge', 17), [])
```