Benchmark: Can add to WeakSet ?

Script Preparation code:

var DATA = (function (K, N, total) {
    function random(n) {
        return Math.floor(Math.random() * 7);
    }

    function randomKey() {
        return Math.random().toString(36).slice(2);
    }

    function randomCollection(count = random(N)) {
        for (var a = new Array(count), i = 0; i < count; i++) {
            a[i] = randomValue();
        }

        return a;
    }

    function randomObject(keysCount = random(N)) {
        for (var obj = {}, i = 0; i < keysCount; i++) {
            obj[randomKey()] = randomValue();
        }

        return obj;
    }

    function randomValue(type = random(K)) {
      switch (type % K) {
        case 0: return undefined;
        case 1: return null; break;
        case 2: return String(Math.random());
        case 3: return Math.random() > 0.5;
        case 4: return Math.random() * 1E3;
        case 5: return randomCollection();
        default: return randomObject();
      }
    }

    return randomCollection(total);
}(7, 5, 1E6));


function canBeAddedToWeakSet_switch2(value) {
  switch (typeof value) {
    case 'undefined':
      return String(value) === '[object HTMLAllCollection]'
    case 'boolean':
    case 'number':
    case 'string':
    case 'symbol':
      return false
    case 'object':
      return value !== null
    default:
      return true
  }
}

function canBeAddedToWeakSet_null_typeof_x2(value) {
    return value !== null && (typeof value === 'object' || typeof value === 'function');
}

function test(canAdd) {
    const count = DATA.reduce((countOfAddables, value) => (canAdd(value) ? 1 : 0) + countOfAddables, 0);
  	console.log('can add %d out of %d values in the array', count, DATA.length);
}

Tests:

Switch-Case 2
test(canBeAddedToWeakSet_switch2);
!== null && (typeof || typeof)
test(canBeAddedToWeakSet_null_typeof_x2);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Switch-Case 2
!== null && (typeof \|\| typeof)

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definition and explain what's being tested.

**Benchmark Definition**

The benchmark defines two test cases:

1. `canBeAddedToWeakSet_switch2`: This function takes a value as input and returns `true` if it can be added to a WeakSet using a switch-case statement.
2. `canBeAddedToWeakSet_null_typeof_x2`: This function takes a value as input and returns `true` if it can be added to a WeakSet by checking if the value is not null and either an object or a function.

**Options Compared**

The two test cases compare different approaches to check if a value can be added to a WeakSet:

* `canBeAddedToWeakSet_switch2`: Uses a switch-case statement to check the type of the value.
* `canBeAddedToWeakSet_null_typeof_x2`: Uses a combination of the null and typeof operators to check the type of the value.

**Pros and Cons**

Here are some pros and cons of each approach:

1. `canBeAddedToWeakSet_switch2`:
	* Pros: Simple and easy to understand, can be optimized for specific types (e.g., using a lookup table).
	* Cons: May not work correctly for certain edge cases or values with complex types.
2. `canBeAddedToWeakSet_null_typeof_x2`:
	* Pros: More general-purpose and handles more edge cases than the switch-case approach.
	* Cons: Less efficient, as it involves multiple operations (null check, typeof operator).

**Libraries and Special JS Features**

There is no explicit library used in this benchmark definition. However, the `WeakSet` data structure is a built-in JavaScript feature.

**Other Considerations**

When working with WeakSets, it's essential to consider the following:

* WeakSets are designed for storing unique values without ensuring any particular order or structure.
* When adding values to a WeakSet, the value must be non-null and not already present in the set.
* The `typeof` operator can return unexpected results for certain types (e.g., symbols).

**Alternatives**

Other approaches to check if a value can be added to a WeakSet might include:

* Using a lookup table or optimization technique specific to the expected input types.
* Utilizing other JavaScript data structures, such as Sets or Maps, which may provide similar functionality with different performance characteristics.

For this specific benchmark, the two test cases `canBeAddedToWeakSet_switch2` and `canBeAddedToWeakSet_null_typeof_x2` provide a clear comparison between different approaches to handling type checking in WeakSets.

Related benchmarks:

Can add to WeakSet ? (version: 0)

How to check beforehand that the value won't throw exception when added to WeakSet in JavaScript? What is the most performant way?

Comparing performance of: Switch-Case 2 vs !== null && (typeof || typeof)

Created: 8 years ago by: Guest

Jump to the latest result

Switch-Case 2

!== null && (typeof || typeof)

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):