feat(collections): add partitionEntries

[scarf005]

Rationale

The collection functions for arrays and objects are mostly in parity, such as filter{keys,values,entries}. However, partition is available only for arrays.

Implementaion and testing

bulk of the code and test are copied from filterEntries, as the only difference was not discarding entries that does not match given predicate.

Example usage

Example usages

const args = {
  "armor_bullet": 30,
  "id": "item_id1",
  "name": "item1",
  "armor_bash": 46,
  "material": "nanite",
  "armor_cut": 30,
  "weight": "460 g",
  "volume": "430 ml",
  "armor_acid": 80,
  "armor_foo": 123,
  "armor_bar": 456,
  "armor_baz": 789,
  "flags": ["foo", "bar", "baz"],
}

before:

import { partition } from "https://deno.land/std/collections/partition.ts"

const [armors, notArmors] = partition(Object.entries(args), ([key]) => key.startsWith("armor_"))
const armorskeys = armors.map(([key, value]) => [key.replace("armor_", ""), value])

const result = {
  armor: Object.fromEntries(armorskeys),
  ...Object.fromEntries(notArmors),
}

after:

import { partitionEntries } from "https://deno.land/std/collections/partition_entries.ts"

const [armors, notArmors] = partitionEntries(args, ([key]) => key.startsWith("armor_"))
const armorskeys = mapKeys(armors, (key) => key.replace("armor_", ""))
  
const result = {
  armor: armorskeys,
  ...notArmors,
}

[CLAassistant]

All committers have signed the CLA.

[kt3k]

Looks like a reasonable addition to me. LGTM