Can Regular Expressions Match Consecutive Repeated Characters?

Matching Repeated Characters with Regular Expressions: Exploring the Limits of Regex

When attempting to match strings that contain three or more consecutive repeated characters, regular expressions can encounter limitations. Despite numerous attempts using various syntax, the desired result has proven elusive. The issue lies in the inability of regular expressions to enforce consecutiveness in matches.

One common approach is to use a character class with a quantifier, such as [A-Za-z0-9]{3,}. However, this approach matches any combination of three characters, not necessarily consecutive ones. A similar issue arises when using (.){3,}, which matches any three characters, regardless of their order.

The most specific syntax, (.)1{3,}, attempts to address the consecutiveness issue by capturing the preceding character and using a backreference to match its повторения. Unfortunately, this approach fails because regular expressions do not support irregular backreferences in the context of a quantifier.

The key insight is that what is required is a technique that can verify consecutiveness. Since irregular backreferences are not supported in Go's RE2 regular expression engine, other approaches must be explored. Consider using a different regular expression library that supports backreferences, such as PCRE bindings.

Alternatively, a custom string parser can be developed to manually check for repeated characters and consecutiveness. This approach would not rely on regular expressions and would provide complete control over the matching process.

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