Benchmark: rcss split vs regex

Tests:

split + regex
const eventSelectorRegex = /\[(#|\.)[a-zA-Z0-9_-]+\]/; let item = '@mousemove.clientX[.sidenav]'; let arr = item.substr(1).split('.'); let eventName = arr[0]; let eventPropName = arr[1];
regex
const regex = /@([a-zA-Z0-9_]+\b)(?:\[((?:#|\.)[a-zA-Z0-9_-]+)\]|)\.([a-zA-Z0-9_]+\b)/; let item = '@mousemove.clientX[.sidenav]'; let res = item.match(regex); let eventName = res[1]; let eventPropName = res[2]; let selector = res[3];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
split + regex
regex

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:75.0) Gecko/20100101 Firefox/75.0

Browser/OS: Firefox 75 on Windows

View result in a separate tab

Test name	Executions per second
split + regex	4349445.0 Ops/sec
regex	8112079.5 Ops/sec

Autogenerated LLM Summary (model llama3.1:latest, generated one month ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark test case.

**Benchmark Test Case:**

The test case compares two approaches for parsing an event selector string:

1. **Split + Regex**: This approach uses JavaScript's `split()` method to split the event selector string into parts, followed by a regular expression (regex) to extract the required information.
2. **Regex-only**: This approach uses a single regex pattern to match and extract the required information from the event selector string.

**Library/Feature Used:**

None are used in this test case.

**Explanation:**

The test case is designed to measure the performance of parsing an event selector string, which is commonly used in web development. The string format is `@eventName[selector]`, where `eventName` is the name of the event (e.g., "mousemove"), and `[selector]` is a CSS selector (e.g., ".sidenav").

In the **Split + Regex** approach:

* The `split()` method splits the event selector string at the first character (`@`) to separate the event name from the rest of the string.
* A regex pattern `/\\[(#|\\.)[a-zA-Z0-9_-]+\\]/` is used to extract the CSS selector from the remaining string.

In the **Regex-only** approach:

* A single regex pattern `/@([a-zA-Z0-9_]+\\b)(?:\\[((?:#|\\.)[a-zA-Z0-9_-]+)\\]|)\\.([a-zA-Z0-9_]+\\b)/` is used to match and extract the event name, CSS selector, and any other information from the event selector string.

**Pros/Cons:**

The **Split + Regex** approach may be more readable and maintainable for developers familiar with JavaScript's `split()` method. However, it requires two separate operations (splitting and regex matching), which might incur additional overhead.

The **Regex-only** approach is a single operation that can match and extract the required information in one step. However, regex patterns can be complex to write and debug, especially for those without prior experience.

**Other Alternatives:**

Other alternatives could include:

* Using a dedicated event selector parsing library (e.g., `event-sel`).
* Implementing a custom parser using a more efficient algorithm (e.g., using a trie data structure).
* Using a different approach altogether (e.g., using a string manipulation library like `string-slice`).

Note that these alternatives are not tested in this specific benchmark, but they might be relevant depending on the use case and performance requirements.

Related benchmarks:

rcss split vs regex (version: 3)

Comparing performance of: split + regex vs regex

Created: 4 years ago by: Registered User

Jump to the latest result

split + regex

regex

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated one month ago):