Benchmark: path regex - MeasureThat.net

Script Preparation code:

var precomp = new RegExp(/[^A-Za-z0-9.-]+|(?=[-A-Za-z])|(?<=[A-Za-z])|(?<=\.\d+)(?=\.)/g);
var test = "M 0 0 L 10 10 L10 10 L20 20 M 0 0 L 10 10 L10 10 L20 20 M 0 0 L 10 10 L10 10 L20 20 M 0 0 L 10 10 L10 10 L20 20";

Tests:

precomp
test.split(precomp);
literal
test.split(/[^A-Za-z0-9.-]+|(?=[-A-Za-z])|(?<=[A-Za-z])|(?<=\.\d+)(?=\.)/g);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
precomp
literal

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

MeasureThat.net provides a platform for testing JavaScript microbenchmarks, where users can create and run their own benchmarks or use pre-existing ones. The current benchmark is defined in two parts:

1. **Script Preparation Code**: This section defines a regular expression (`precomp`) that will be used to test the performance of various approaches.
2. **Individual Test Cases**: These are two separate tests that demonstrate different approaches for splitting a string using the `split()` method.

**Test Cases**

Let's analyze each test case:

### Test Case 1: "precomp"

This test uses the `new RegExp()` constructor to create a regular expression (`precomp`) and then passes it to the `split()` method.
```javascript
var precomp = new RegExp(/[^A-Za-z0-9.-]+|(?=[-A-Za-z])|(?<=[A-Za-z])|(?<=\\.\\d+)(?=\\.)/g);
```
The regular expression `precomp` matches one or more of the following patterns:

* Non-alphanumeric characters (`[^A-Za-z0-9.-]`)
* A hyphen followed by an alphabetic character (`[-A-Za-z]`)
* An alphabetic character preceded by another alphabetic character (`(?<=[A-Za-z])`)
* A dot followed by a digit (`(?<=\\.\\d+)(?=\\.)`)

**Pros and Cons**

Using `new RegExp()` can be beneficial when you need to create a complex regular expression, but it comes with some drawbacks:

* Performance overhead due to the creation of a new regex object
* Potential security risks if not validated properly

**Test Case 2: "literal"**

* Non-alphanumeric characters (`[^A-Za-z0-9.-]`)
* A hyphen followed by an alphabetic character (`[-A-Za-z]`)
* Word characters (`\w`)
* A dot followed by a digit (`\.\d+\.`)

**Pros and Cons**

Using a literal regular expression can be beneficial when you need to create a simple, well-defined pattern, but it may not offer the same level of flexibility as `new RegExp()`.

**Library: String.prototype.split()**

The `split()` method is a built-in JavaScript method that splits a string into an array of substrings based on a regular expression. The library used here is the native JavaScript library.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntax mentioned in this benchmark.

**Alternatives**

If you're interested in exploring alternative approaches for splitting strings, consider using:

* `Array.prototype.reduce()`: Instead of using `split()` and concatenating arrays, you can use `reduce()` to build the output array.
* `String.prototype.replaceAll()`: This method replaces all occurrences of a pattern with another value, which can be useful for string manipulation tasks.
* Custom implementations: Depending on your specific requirements, you might consider implementing your own custom solution using loops or other algorithms.

Keep in mind that these alternatives may offer different performance characteristics and trade-offs compared to the `split()` method.

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36

Browser/OS: Chrome 129 on Linux

View result in a separate tab

Test name	Executions per second
precomp	20032.2 Ops/sec
literal	20092.2 Ops/sec

Related benchmarks:

path regex (version: 0)

Comparing performance of: precomp vs literal

Created: 3 years ago by: Guest

Jump to the latest result

precomp

literal

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):