Benchmark: Subsequence by string manipulation or regex

Script Preparation code:

var string = "Hello world";

function subsequence_re(str) {
  let final = []
  for(var i = 0; i < str.length; i += 1) {
    final[i] = "(" + str[i] + ")+";
  }
  return new RegExp(final.join("(.)*"));
}

function subsequence(a, b) {
  let index = 0
  for(let char of b) {
    if (a[index] === char) index += 1
  }
  return index == a.length
}

var regexp = subsequence_re("Hello")

Tests:

subsequence_re
subsequence_re("Hello").test(string);
subsequence
subsequence("Hello", string);
subsequence_re (using already determined regexp)
regexp.test(string);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
subsequence_re
subsequence
subsequence_re (using already determined regexp)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36

Browser/OS: Chrome 89 on Linux

View result in a separate tab

Test name	Executions per second
subsequence_re	512908.3 Ops/sec
subsequence	1936756.9 Ops/sec
subsequence_re (using already determined regexp)	1267451.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested.

**Benchmark Overview**

The benchmark compares three approaches to finding a subsequence in a given string:

1. **Subsequence by string manipulation or regex (subsequence_re)**: This approach uses a regex to create a pattern that matches any sequence of characters from the original string.
2. **Simple subsequence check (subsequence)**: This approach checks if each character in the subsequence is present in the original string at least once.

**Options Compared**

The benchmark compares the performance of these two approaches:

* **Subsequence_re**: This approach uses regex to create a pattern that matches any sequence of characters from the original string.
* **Simple subsequence check (subsequence)**: This approach checks if each character in the subsequence is present in the original string at least once.

**Pros and Cons**

Here are some pros and cons of each approach:

* **Subsequence_re**:
	+ Pros:
		- Can be more efficient for large sequences, as it uses a single regex operation.
		- Can be more concise and readable.
	+ Cons:
		- May not work well for very long strings or complex patterns.
		- May be less intuitive for non-experts.
* **Simple subsequence check (subsequence)**:
	+ Pros:
		- Easy to understand and implement.
		- Works well for most use cases.
	+ Cons:
		- May be slower than the regex approach for large sequences.

**Libraries and Special JS Features**

There is no specific library used in this benchmark. However, it's worth noting that the `RegExp` object is a built-in JavaScript object that provides regular expression functionality.

No special JavaScript features are used in this benchmark.

**Other Considerations**

* The benchmark uses Chrome 89 as the browser and Linux as the operating system.
* The benchmark runs multiple iterations of each test case to ensure accurate results.
* The `ExecutionsPerSecond` value represents the number of times each test case is executed per second, which can be used to compare performance.

**Alternative Approaches**

Other possible approaches for finding a subsequence in a given string include:

* Using a data structure like an array or set to keep track of characters that have been seen so far.
* Using a more advanced algorithm like the Knuth-Morris-Pratt (KMP) algorithm or the Rabin-Karp algorithm.
* Using a machine learning-based approach, such as training a neural network on a dataset of subsequence examples.

These alternative approaches may offer better performance or accuracy for certain use cases, but they are not tested in this benchmark.

Related benchmarks:

Subsequence by string manipulation or regex (version: 0)

Comparing performance of: subsequence_re vs subsequence vs subsequence_re (using already determined regexp)

Created: 3 years ago by: Guest

Jump to the latest result

subsequence_re

subsequence

subsequence_re (using already determined regexp)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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