Benchmark: replaceAll vs naive implementation

Script Preparation code:

String.prototype.replaceAll = function(search, replacement) {
    var target = this;
  	let idx;
  	let cursoridx = 0;
  	while (true) {
      idx = target.indexOf(search, cursoridx);
      if (idx === -1) break;
      target = target.substring(0, idx) + replacement + target.substring(idx + 1) 
    }
  	return target;
};

Tests:

replace regex
"this.is.it.arts.arst.arst.arst".replace(/\./g, "");
replace All
"this.is.it.arts.arst.arst.arst".replaceAll(".", "");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
replace regex
replace All

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

**Overview of the Benchmark**

The provided JSON represents a JavaScript microbenchmarking test case for measuring the performance difference between two approaches: a naive implementation and a regular expression-based replacement (regex) approach.

**Benchmark Definition**

The benchmark definition consists of two test cases:

1. `replace regex`: This test case uses a regex pattern to replace all occurrences of `\.` with an empty string (`""`).
2. `replace All`: This test case uses the `replaceAll()` method provided in the Script Preparation Code, which is a custom implementation of the `replace()` method.

**Script Preparation Code**

The Script Preparation Code defines the `String.prototype.replaceAll` function, which is used in the `replace All` test case. This implementation replaces all occurrences of a specified search string with a replacement string, and returns the modified string.

```javascript
String.prototype.replaceAll = function(search, replacement) {
  var target = this;
  let idx;
  let cursoridx = 0;
  while (true) {
    idx = target.indexOf(search, cursoridx);
    if (idx === -1) break;
    target = target.substring(0, idx) + replacement + target.substring(idx + 1)
  }
  return target;
};
```

**Naive Implementation**

The naive implementation is not explicitly defined in the benchmark, but it can be inferred to be a simple loop-based approach that iterates over each character in the string and checks if it matches the search string. If it does, the replacement string is appended.

**Pros and Cons of Approaches**

1. **Regex Approach (replace regex)**:
	* Pros: Regular expressions are often more efficient for complex replacements.
	* Cons: Regex patterns can be slow for simple replacements or when dealing with large strings.
2. **Custom Implementation (replace All)**:
	* Pros: Custom implementation may be optimized for the specific use case and may be faster than regex.
	* Cons: Custom implementation requires manual iteration over each character in the string, which can be slow.

**Other Considerations**

* The `String.prototype.replaceAll` function uses a while loop with no early exit condition, which can lead to unnecessary iterations.
* The custom implementation does not handle edge cases such as null or undefined input strings.
* The benchmark does not account for cache effects or other optimizations that may improve performance.

**Library and Special Features**

There is no explicit library mentioned in the benchmark. However, the `String.prototype.replaceAll` function uses a custom implementation of the `replace()` method.

The `replace All` test case uses the `replaceAll()` method, which is not a standard JavaScript method. It appears to be a custom implementation provided in the Script Preparation Code.

**Alternatives**

Other alternatives for replacing strings in JavaScript include:

* Using the built-in `replace()` method.
* Using a library such as Lodash's `string.prototype.replace()`.
* Implementing a custom replacement function using a loop-based approach, similar to the naive implementation.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.45 Safari/537.36

Browser/OS: Chrome 96 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
replace regex	3021979.5 Ops/sec
replace All	1261694.8 Ops/sec

Related benchmarks:

replaceAll vs naive implementation (version: 0)

Comparing performance of: replace regex vs replace All

Created: 2 years ago by: Registered User

Jump to the latest result

replace regex

replace All

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):