I love regular expressions

[Jef fJacobson]

I use regular expressions regularly. The downside is that it is difficult for newcomers to understand them. But as long as you add comments to your code it shouldn't be a problem. And many languages allow you to add comments WITHIN the regular expressions, making them even easier to understand. (I frequently create my regexes with comments in C# and then take out the comments afterwards, leaving the original version within commented-out code.)

[honey the codewitch]

I actually avoid assembly wherever I can. We have so many different MCUs that come along, and supply is questionable sometimes, which means switching chips mid project. I mean, Arm Cortex M to Arm Cortex M it's not the worst thing in the world, but you'd still have all the CMSIS stuff you'd have to deal with. Ergo, I abstract, and use C++ with ZephyrRTOS for my projects.

Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix

[bryanren]

"cobol".ToUpper()

[honey the codewitch]

jschell wrote:

Not sure what you mean by that.

What I mean is that regardless of the platform you choose, there is a way to run a DFA regular expression on it. And yeah, that encompasses many different engines, which themselves are what run on a particular platform, unless you're doing code generation, which I do sometimes for them so I don't have to include the regex engine in my firmware. That code is easy to make cross platform. You'd almost have to put in extra effort to make it otherwise. :) I was maybe trying to be too brief by half. I assumed the meaning would come through, but I guess not.

jschell wrote:

Perhaps you were referring to that the simplest syntax works in different engines though

In part yes, but also, virtually every platform has a DFA regex engine for it, or alternatively you can generate DFA code for that platform, with something such as my rxcg project. I was intending to imply that as well.

Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix

[honey the codewitch]

I have a love hate relationship with bit twiddling. I don't mind writing that code, but I hate having to read it. And I hate the process of commenting it because it tends to take a compact thing and make it necessarily verbose.

Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix

[honey the codewitch]

That's why you keep your tool to yourself. :laugh:

Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix

[Jeroen_R]

Being a compact way to describe something is very much the problem. That is exactly why people hate them. You can't just read one and know what it does, nor expect that of your colleagues. Every time I add a RegEx to the code, I have to add an explanation of what it does. Just like in code: if it needs comments to be readable, something's very wrong.

[honey the codewitch]

I recall this too. Qwerty I heard was in part laid out to slow typists down so the mechanical typewriter could keep up. I heard it from the Beagle Bros back in the 1980s so I don't know how true it is. Either way, presumably eventually that wasn't an issue anymore. And Devorak was a common alternative, or at least common as qwerty alternatives go. It was touted as better, but despite the hype I remember reading that it didn't actually improve people's WPM.

Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix

[honey the codewitch]

Jeroen_R wrote:

if it needs comments to be readable, something's very wrong.

That's true in the general case, but the exceptions are legion. I'd argue regex is one of those exceptions. There is simply not a more compact and efficient way to tokenize or match flat text than DFA regular expressions. Sure you could try writing it out, but I have. Try your hand at creating a more verbose language than regex and see what it looks like. I wrote one that allows you to describe regular expressions using a BNF notation variant. The result required too much typing, let's put it that way, even though BNF is fairly compact as well. If there's a better mousetrap, nobody seems to have found it yet.

Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix

[k5054]

Not keeping your tool to yourself is one of the leading causes of dismissal, too.

"A little song, a little dance, a little seltzer down your pants" Chuckles the clown

[Ron Anders]

This is the most runaway thread on CP in a long while. Way to poke the bear.

[Lost User]

I blank out on regular expressions. Too much like learning a new language. The other day, I needed to get 0 or more leading characters from a string (as an int). I Googled (regex), I went, I left. Coding challenge: get leading digits (I settled for LINQ)

var text = "123rd NY 2nd Battalion".
//
var count = text.TakeWhile( c => Char.IsDigit( c ) ).Count();
int i = count > 0 ? ConvertToInt32( text.SubString( 0, count) ) : 0;

Answer: 123

"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I

[Mark Starr]

I didn’t mean to imply you didn’t participate in the conversation, rather that the topic usually starts up a lively discussion. :cool:

Time is the differentiation of eternity devised by man to measure the passage of human events. - Manly P. Hall Mark Just another cog in the wheel

[honey the codewitch]

^[0-9]+

Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix

[BernardIE5317]

i enjoy the challenge of learning / writing regular expressions for my text editing of source code . as in all things mastering it is the same as being invited to perform at Carnegie Hall id est "practice practice practice" . my purpose in this post though is to express my impression from these many and expert posts utilizing fancy schmancy terms of which i do not know which seem to indicate regular expressions are more powerful / advanced / sophisticated than i know as i understand them to be nothing more than a text editing convenience . may i please inquire am i wrong in this regard . thank you kindly .

[honey the codewitch]

They're for text processing, but for more than text editing. The C# compiler for example, almost certainly uses a tokenizer built up of regular expressions. That said, you're basically not wrong. I mean, tokenization is almost like text matching, but with a twist.

Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix

[honey the codewitch]

Can confirm.

Check out my IoT graphics library here: https://honeythecodewitch.com/gfx And my IoT UI/User Experience library here: https://honeythecodewitch.com/uix

[jmaida]

Agree. A good and practical recommendation!

"A little time, a little trouble, your better day" Badfinger

[jmaida]

cool. forgot chatgpt is hanging out there

"A little time, a little trouble, your better day" Badfinger

[jmaida]

lordy... "its a bad worker who blames their tools." "there is no tool like an old tool." :)

"A little time, a little trouble, your better day" Badfinger