Benchmark: MDS Test - MeasureThat.net

Script Preparation code:

var line = 'LSD|*|1|*|4185|*|4185|*|487|*|1337|*|Metabolic Disease Enzyme Replacement, Severe Comb Immune Def*~*'
var nthIndex = function(str, pat, n) {
	var i;
  for (i = 0; n > 0 && i !== -1; n -= 1) {
		i = str.indexOf(pat, i ? (i + 1) : i);
  }
  return i;
};

Tests:

Old
var parsedLine = line.substring(line.indexOf('|*|', (line.indexOf('|*|') + 3)) + 3).replace(/\\/g, '') return parsedLine;
New
var parsedLine = line.substring(nthIndex(line, '|*|', 2) + 3).replace(/\\/g, '') return parsedLine;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Old
New

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'd be happy to explain the benchmark and its various components.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmarking test on MeasureThat.net. The test is designed to measure the performance of two different approaches for parsing a specific string pattern in JavaScript.

**Script Preparation Code**

The script preparation code is a JavaScript function that defines a line string `line` containing the target pattern to be parsed:
```
var line = 'LSD|*|1|*|4185|*|4185|*|487|*|1337|*|Metabolic Disease Enzyme Replacement, Severe Comb Immune Def*~*'
```
The script also defines a nested function `nthIndex` that takes three arguments: the input string `str`, the pattern to search for `pat`, and an optional parameter `n`. The purpose of this function is to find the index of the nth occurrence of the pattern in the string.

**Benchmark Definition**

The benchmark definition consists of two test cases:

1. **Old**: This test case uses a simple string manipulation approach to parse the line string:
```
var parsedLine = line.substring(line.indexOf('|*|', (line.indexOf('|*|') + 3)) + 3).replace(/\\\\/g, '')
```
This code substrings the line starting from the first occurrence of `|*|` (plus 3 characters) and then removes any backslashes (`\`) from the resulting string.

2. **New**: This test case uses the previously defined nested function `nthIndex` to parse the line string:
```
var parsedLine = line.substring(nthIndex(line, '|*|', 2) + 3).replace(/\\\\/g, '')
```
This code calls the `nthIndex` function with the input string and pattern as arguments, then substrings from the resulting index plus 3 characters. Finally, it removes any backslashes from the resulting string.

**Library and Special JavaScript Features**

In this benchmark, no libraries are explicitly mentioned. However, the use of the `indexOf` method on a string is standard JavaScript syntax. No special JavaScript features or syntax are used in these test cases.

**Options Compared**

The two test cases compare two different approaches for parsing the line string:

1. **Simple Substring Extraction**: The "Old" test case uses a straightforward substring extraction approach.
2. **Nested Function Approach**: The "New" test case uses a nested function (`nthIndex`) to find the index of the first occurrence of `|*|` and then extracts the desired substring.

**Pros and Cons**

Here are some pros and cons of each approach:

1. **Simple Substring Extraction (Old)**:
	* Pros: Simple, easy to understand, and well-documented.
	* Cons: May not be efficient for large strings or multiple occurrences of `|*|`.
2. **Nested Function Approach (New)**:
	* Pros: Can handle multiple occurrences of `|*|` efficiently by using the index returned by `nthIndex`. Reduces code duplication.
	* Cons: More complex, requires understanding of nested functions and their applications.

**Other Considerations**

When evaluating performance, consider factors like:

1. String manipulation overhead
2. Number of occurrences of `|*|`
3. Browser engine support for regular expressions

**Alternatives**

If you were to reimplement this benchmark or create a similar one, consider using:

1. Regular Expressions (RegEx) instead of string manipulation approaches.
2. Use cases where RegEx is more suitable and efficient.

The use of RegEx would simplify the `nthIndex` function and reduce code duplication. However, be mindful that RegEx can have overhead due to compilation and matching.

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36

Browser/OS: Chrome 68 on Windows

View result in a separate tab

Test name	Executions per second
Old	1422278.9 Ops/sec
New	1321763.8 Ops/sec

Related benchmarks:

MDS Test (version: 0)

Testing Parser Performance

Comparing performance of: Old vs New

Created: 7 years ago by: Guest

Jump to the latest result

Old

New

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):