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Regex multiline whitespace tested
(version: 0)
Comparing performance of:
Simple regex vs Non backtracking regex
Created:
3 years ago
by:
Guest
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Tests:
Simple regex
" \n \n \n \n \n \n\n\n \n \n\n \n \n \n \n \n\n\n \n \n\n \n \n".match(/\s*\n\s*/g)
Non backtracking regex
" \n \n \n \n \n \n\n\n \n \n\n \n \n \n \n \n\n\n \n \n\n \n \n".match(/[^\S\n]*\n\s*/g)
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Suite status:
<idle, ready to run>
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Test case name
Result
Simple regex
Non backtracking regex
Fastest:
N/A
Slowest:
N/A
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
I'll break down the benchmark and explain what's being tested, compared, and the pros/cons of each approach. **Benchmark Overview** The benchmark measures the performance of two different regular expression (regex) patterns on multiline whitespace in JavaScript engines. **Options Compared** There are two regex patterns being compared: 1. **Simple regex**: `"\n\n" .match(/\s*\\n\s*/g)` 2. **Non-backtracking regex**: `"\\n\\s*" .match(/[^\\S\\n]*\\n\\s*/g)` **Pros and Cons of Each Approach** 1. **Simple Regex** * Pros: + Easier to read and understand + Less prone to errors due to the use of `\s*` * Cons: + May not be as efficient, as it uses a lazy match (`\s*`) instead of a more aggressive match (`\\n`) 2. **Non-Backtracking Regex** * Pros: + More efficient, as it uses a more aggressive match (`[^\\S\\n]*`) to consume all whitespace characters before the newline * Cons: + More complex and harder to read due to the use of `[^\\S\\n]` + May be more prone to errors if not implemented correctly **Library and Purpose** There is no explicit mention of a library being used in this benchmark. However, it's likely that the regex patterns are being executed using the built-in JavaScript engine. **Special JS Features or Syntax** None mentioned. The benchmark only uses standard JavaScript features. **Other Considerations** * The use of `g` flag at the end of each regex pattern ensures that all matches are found, not just the first one. * The `\\n` and `\\s` escape sequences are used to represent newline and whitespace characters, respectively. **Alternatives** Other approaches could be taken to measure the performance of these regex patterns, such as: 1. Using a different JavaScript engine or implementation (e.g., V8, SpiderMonkey) 2. Adding more complex inputs or edge cases to test the regex patterns' robustness 3. Comparing the performance with other programming languages that have similar regex capabilities In this benchmark, the focus is on comparing the simple and non-backtracking regex approaches within a JavaScript engine, making it a good example for testing the efficiency of different regex implementation strategies.
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