Benchmark: groupConsecutiveNumbers with immutable prepending, large and small arrays

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/immutable/4.0.0-rc.12/immutable.min.js'></script>

Script Preparation code:

const reducerForGroupingConsecutiveNumbers = (accumulator, currentNumber, index) => {
  if (index === 0) {
    accumulator.push([currentNumber]);
  } else {
    const previousGroup = accumulator[accumulator.length - 1];
    const previousNumber = previousGroup[previousGroup.length - 1];
    if (currentNumber === previousNumber + 1 || currentNumber === previousNumber) {
      previousGroup.push(currentNumber);
    } else {
      accumulator.push([currentNumber]);
    }
  }
  return accumulator;
};

/**
 * Will create an array of subarrays of consecutive numbers
 * Given: [0,1,2,5,6,9];
 * Returns: [[0,1,2],[5,6],[9]]
 */
function createGroupingsOfConsecutiveNumbers(array) {
  return array.reduce(reducerForGroupingConsecutiveNumbers, []);
};

const { List } = Immutable;

/** Groups consecutive input values, e.g. [1, 2, 4] -> [[1, 2], [4]] */
function groupConsecutiveNumbers(inputArray) {
  const initialValue = List.of(List.of(Number())); // Use a non-empty initial value to avoid edge cases: https://www.conjur.org/blog/special-cases-are-a-code-smell/
  const groupings = inputArray
    .reduce((accumulator, newNumber) => {
      /* last(accumulator) and last(last(accumulator)) will always be defined because
       * 1. its initial value is an array containing an array with at least one element and
       * 2. we never add array with fewer than 1 elements
       * They can therefore be safely casted as defined */
      const firstSubarray = accumulator.first();
      const firstNumber = firstSubarray.first();

      const isConsecutive = newNumber === firstNumber + 1 || newNumber === firstNumber;
      if (isConsecutive) {
        return accumulator.shift().unshift(firstSubarray.unshift(newNumber));
      }
      return accumulator.unshift(List.of(newNumber));
    }, initialValue)
    .toJS()
    .map((x) => x.reverse())
    .reverse();
  const [initialValueGroup, ...rest] = groupings;
  const withoutInitialValue = [initialValueGroup.slice(1), ...rest].filter((array) => array.length > 0);
  return withoutInitialValue;
}

Tests:

imperative (large arrays)
const numbersFromOneUpToTenThousandNotDivisibleByThree = [...Array(10000).keys()].filter(s => s % 3 !== 0); createGroupingsOfConsecutiveNumbers(numbersFromOneUpToTenThousandNotDivisibleByThree)
functional (large arrays)
const numbersFromOneUpToTenThousandNotDivisibleByThree = [...Array(10000).keys()].filter(s => s % 3 !== 0); groupConsecutiveNumbers(numbersFromOneUpToTenThousandNotDivisibleByThree)
imperative (small arrays)
const smallArray = [0, 1, 2, 5, 6, 9]; createGroupingsOfConsecutiveNumbers(smallArray)
functional (small arrays)
const smallArray = [0, 1, 2, 5, 6, 9]; groupConsecutiveNumbers(smallArray)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
imperative (large arrays)
functional (large arrays)
imperative (small arrays)
functional (small arrays)

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.183 Safari/537.36

Browser/OS: Chrome 86 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
imperative (large arrays)	1345.1 Ops/sec
functional (large arrays)	96.6 Ops/sec
imperative (small arrays)	5512572.5 Ops/sec
functional (small arrays)	115993.3 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark and explain what's being tested, compared options, pros and cons of each approach, library usage, special JavaScript features or syntax, and alternative approaches.

**Benchmark Test**

The benchmark measures the performance difference between two approaches:

1. **Imperative**: Using a traditional loop (e.g., `for` loop) to group consecutive numbers in an array.
2. **Functional**: Using a functional programming approach with recursion and immutable data structures to group consecutive numbers in an array.

**Options Compared**

The benchmark compares the performance of two imperative approaches:

1. **createGroupingsOfConsecutiveNumbers**: The original implementation using a custom reducer function.
2. **groupConsecutiveNumbers**: An alternative implementation using Immutable.js, a library for functional programming in JavaScript.

The benchmark also compares the performance of two functional approaches:

1. **createGroupingsOfConsecutiveNumbers** (imperative): Using a traditional loop to group consecutive numbers.
2. **groupConsecutiveNumbers** (functional): Using Immutable.js and recursion to group consecutive numbers.

**Pros and Cons of Each Approach**

* Imperative approach:
	+ Pros: Can be more intuitive for beginners, easier to understand the logic.
	+ Cons: May lead to performance issues due to overhead from managing loops and state.
* Functional approach with Immutable.js:
	+ Pros: Can provide better performance and concurrency benefits due to immutable data structures and recursion.
	+ Cons: May require a stronger understanding of functional programming concepts.

**Library Usage**

The benchmark uses Immutable.js, a library for functional programming in JavaScript. Specifically, it uses the `List` type from Immutable.js to create an initial value with at least one element, which is then used as a starting point for recursion.

**Special JavaScript Features or Syntax**

There are no special JavaScript features or syntax mentioned in this benchmark that are specific to modern JavaScript versions or ECMAScript standards. However, the use of `const` and template literals (`\r\n`) suggests that the code is written in modern JavaScript syntax.

**Alternative Approaches**

Other alternative approaches could include:

1. Using a library like Lodash or Ramda for functional programming.
2. Implementing a custom data structure, such as a tree or graph, to group consecutive numbers.
3. Using parallel processing or concurrent execution techniques to compare the performance of different approaches.

Overall, this benchmark provides a useful comparison between imperative and functional programming approaches for grouping consecutive numbers in an array, highlighting the benefits and trade-offs of each approach.

Related benchmarks:

groupConsecutiveNumbers with immutable prepending, large and small arrays (version: 0)

Comparing performance of: imperative (large arrays) vs functional (large arrays) vs imperative (small arrays) vs functional (small arrays)

Created: 4 years ago by: Registered User

Jump to the latest result

imperative (large arrays)

functional (large arrays)

imperative (small arrays)

functional (small arrays)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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