The true power of regular expressions (2012)
1–10 of 62 posts
Re: The true power of regular expressions (2012)
#2Some people, when confronted with a problem, think "I know, I'll get my agent to solve it with regular expressions."
Now they have three problems.
Re: The true power of regular expressions (2012)
#3"Doom Using Regular Expressions" https://news.ycombinator.com/item?id=49094081
Re: The true power of regular expressions (2012)
#4Something that seems obvious but not always implied by people's comments is that people are rarely trying to match an entire document with a regular expression so it doesn't really matter that "HTML is not a regular language".
If I am trying to e.g. count div tags with a regex like "As soon as you also add character classes to ignore various parts of the document that you are not interested in like "]*>" or whatever it is, then it is eminently useful even if the bit we are ignoring is not fully regular.
One lovely thing about regex is how fast it is. I was asked to parse a massive CAN Bus log file for how many times some event had logged. This was the early 2000s and the file was 6GB, which was pretty big. I tried .Net's string.StartsWith or something and that took ages to run through the file. I did the same thing with a regex and it finished in like 5 seconds (HDD, not SSD!). I don't know how the magic works but it is very impressive.
Re: The true power of regular expressions (2012)
#5Just like jq there will be some lad along to tell us that "I don't like the syntax and find it confusing" not realising that's the exact superpower it presents is it's terseness is a key property to it's adoption. jq and regex really are sort of handy one liners that you invoke in other scripts and you explain what they do in your script with a comment.
Re: The true power of regular expressions (2012)
#6Every time I cut-n-paste a regex into code, I comment with the url of the spell book page I copied so future me can answer, "WTF does this do again?"
Re: The true power of regular expressions (2012)
#7[dead]
Re: The true power of regular expressions (2012)
#8The last thing we need is huge regexs made by AI
Re: The true power of regular expressions (2012)
#9Every time I cut-n-paste a regex into code, I comment with the url of the spell book page I copied so future me can answer, "WTF does this do again?"
I'm wary of external urls in code. Some plaintext comment would come in handy for the day the link inevitably goes dead.
Re: The true power of regular expressions (2012)
#10> The regular expression is very simple
OT but this me-problem makes me angry every time I read it. Nothing is simple, otherwise it is trivial and not worth mentioning. I can't read over this without thinking that I'm not smart enough to wrap my head around something instantly.