Questions tagged [regular-expressions]
According to Wikipedia, a regular expression (abbreviated regex or regexp) is a sequence of characters that forms a search pattern, mainly for use in pattern matching with strings, or string matching, i.e. "find and replace"-like operations.
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Programming language independent semantic validation of message protocol
I have a proprietary protocol that describes the exchange of messages of two participants (applications) via a messaging broker (mqtt). A participant is of type A or B. Each type is allowed to send ...
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Designing a Python string validation library
My employer has a significant number of company-internal strings which require format validation. For instance, order number AAA-BBB-CCC, stock number AB-123456 or factory ABC1 - Regex with extras (...
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How to implement a RegEx library in C [closed]
Background I have been attempting to create a line editor in C, eventually becoming a visual editor, and as a means of both allowing the editor to be useful but also learn more about C development, I ...
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Is exposing regex in error response to end user bad practice?
Say I have a have request payload PUT /user { email: "invalid" ... } In the backend there is a email regex, which I cannot modify. Currently the behavior is to output: { "error&...
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Alternative to using regex in Python
Background I do programming with Python and now and then i run into a situation where i have to use regex Typically i try to learn a bit about it and look at examples of doing things similar to what i'...
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Domain specific language for regex processing
I am working on a DSL for text processing. The core is searching for regular expressions with some operators around them. These searches are embedded into a more procedural program, which allows for ...
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In what programming language is Python's regex module written in? [closed]
If I try to rewrite specific regex functionalities (e.g. substituting a string) in Python, a solution using the regex module is always faster. Is regex written in C?
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What is the right algorithm to match regex on a stream?
I'd like to match a regex pattern on a stream, but I am not sure what algorithm to use. I certainly don't want to load the entire file into memory. I tried to figure out how to do this, but I have ...
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What is the best use case of a regular expression (TripleByte question)?
I have lots of experience with regexes. I just want to make sense of this. Am I missing something here. Which one of these would you rather validate with a regex? Question reads, Which of the ...
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portable hashable string representation of data object
I have a class of (flat) objects that are going to be passed around between three different parties, each possibly running a different software stack. my_object: item: "string_a" money: ...
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Is it possible to create a regular language from an non regular language?
I am wondering if it is possible to create a regular language from a irregular language if we add or remove finite number of words from it? say L is irregular, can we add or remove finite number of ...
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What is the optimal way to perform 5000 unique string replace functions in terms of performance?
Restructuring some code, and the way I built it up over time has portions that look something like this: s.replace("ABW"," Aruba "); s.replace("AFG"," Afghanistan "); s.replace("AGO"," Angola "); s....
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Is it a good practice to include empty/white space checks in RegEx?
The goal of the RegEx is to match exactly 6 characters, but in addition it should match empty strings or white space (e.g: ^$|\s|^(\w){6}$). Is it good practice check for empty string/white space in a ...
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Why are `]` and `}` not metacharacters in Regex when ')' is?
In Regular Expressions Quick Start, it reads Twelve characters have special meanings in regular expressions: the backslash \, the caret ^, the dollar sign $, the period or dot ., the vertical bar or ...
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Guarding user input of regular expressions against attacks
I am aware of Regular Expression Denial of Service (ReDoS). Is there any reasonable way to allow users to create custom regexes while guaranteeing that they don't submit an exponentially slow pattern?
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