How to Split a String into Chunks Without Breaking Numbers in Elixir

Описание: Discover an efficient way to handle large strings in Elixir by chunking them into manageable pieces without breaking numbers.
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This video is based on the question https://stackoverflow.com/q/69354495/ asked by the user 'Mircea' ( https://stackoverflow.com/u/4629810/ ) and on the answer https://stackoverflow.com/a/69355221/ provided by the user 'Adam Millerchip' ( https://stackoverflow.com/u/1225617/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Introduction

Handling strings in programming can often present unique challenges, especially when you need to apply specific constraints. If you’ve ever faced the dilemma of splitting a string into smaller parts without exceeding a length limit and ensuring that you don’t break a number in half, you’ll know how tricky it can be. This is a common problem in Elixir, especially when working with data from an external source.

In this guide, we’ll walk through a solution to split a string created from a list of integers. Each part of the split will be limited to a maximum of 100 characters, ensuring that the split occurs only at spaces and never in the middle of a number.

The Problem

The task at hand includes two primary components:

Convert a list of integers into a string: These integers may come from an external source, and for our purposes, we’ll join them into a string separated by spaces.

Split the resulting string without breaking any numbers: The challenge here is to ensure that each chunk of the string does not exceed 100 characters and that we do not split any numbers in half – meaning we can only split at spaces.

While the first part—converting integers to a string—is fairly straightforward, adhering to the constraints of the second part is where the complexity arises.

The Solution

To tackle this problem, we will create a function called join_len/2 in Elixir. This function will effectively manage both tasks in a single pass. Here’s how the function works:

Function Overview

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Function

Module Definition and Disclosure: We define an Elixir module called Example which contains our primary function.

Function Signature: The main function join_len/2 takes two parameters, an enum of integers and the maximum length for each chunk.

Base Cases: The recursive function serves to build the output as it evaluates each integer in the provided list:

When the enum is empty, it returns the result.

If the current string is empty, it begins with the first number.

Handling Strings: For each number:

It converts the number to a string and checks the size.

If appending the number (with a space) to the current chunk doesn't exceed the length, it’s appended.

If it does exceed the limit, it starts a new chunk with the current number.

Testing the Function

To verify our function works as expected, we can run the test function:

[[See Video to Reveal this Text or Code Snippet]]

Expected Output

Running the test function with a list of repeating integers will yield output like this:

[[See Video to Reveal this Text or Code Snippet]]

This output demonstrates that the function successfully creates chunks of the string without exceeding the character limit or splitting any numbers.

Conclusion

In this post, we've tackled a common issue in string manipulation within Elixir—maintaining the integrity of numbers while splitting a string. By utilizing a recursive approach and leveraging Elixir’s powerful features, we’ve created an efficient solution that tackles both converting integers to a string and splitting it into manageable lengths.

Feel free to borrow this technique for your projects where similar string manipulation is needed!