6 ms·

I remember when people used to argue about regex being bad or good, with a lot of low quality regex introducing bugs in codebases. Now we have devs asking AI t

I remember when people used to argue about regex being bad or good, with a lot of low quality regex introducing bugs in codebases. Now we have devs asking AI to generate regex formulas and pasting it into code without much concern on its validity.

mFixman 2y ago
Regexes are easy to test. Bad developers do bad regexes, regardless of whether they used AI.
- Etherlord87 2y ago
  How do you test a regex to be 100% sure it's valid? I don't think it's possible.
  - fkyoureadthedoc 2y ago
    True for most things I think
  - eutropia 2y ago
    If it's using classical regex, without backtracking or other extensions, a regular expression is isomorphic to a state machine. You can enumerate combinations doing something like this: https://stackoverflow.com/a/1248566 https://stackoverflow.com/a/1248566 kids these days and their lack of exposure to finite automata
    - Etherlord87 2y ago
      - Vehicle steering is easy to test. - How so? I don't think it's possible to test for all cases... - Well, it's easy, assuming a car on a non-branching track, moving with a constant speed and without any realistic external influences on it, you can simply calculate the distance traveled using the formula s = v/t. Ah, I wish I'd stop running into fools not knowing Newton's first law of motion... - ??? Are you well?
      - loamaa 2y ago
        I understand you want to refute/diminish the parent comment on finite automata, but I think you are providing a straw man argument. The parent comment does provide an interesting, factual statement. I don't believe finite state automata are at all close in complexity to real-world self-driving car systems (or even a portion thereof). Your closing statement is also dismissive and unconstructive. I believe finite state modeling is used at NASA, A google search brings up a few references (that I'm probably not qualified to speak to), and I also remember hearing/reading a lecture on how they use them to make completely verifiable programs but can't find the exact one at the moment.
        Etherlord87 2y ago
        I wasn't making a strawman, I was making a parody of his strawman. I thought it's obvious, since I was making an analogy, and it was an analogy to his argument.
      - eutropia 2y ago
        I should have been more clear perhaps: many regexes are capable of being verified with 100% certainty: https://en.m.wikipedia.org/wiki/Thompson%27s_construction https://en.m.wikipedia.org/wiki/Thompson%27s_construction But not all regexes (eg, those using PCRE extensions afaik) are amenable to such a treatment. Those you just tend to hope they work.
  - spurgu 2y ago
    Aren't you asking how to create software without bugs?
    - Etherlord87 2y ago
      Well regex isn't Turing-complete, so it's not exactly an analysis of a program. You could reason about regex, about tokens, then describe them in a way that satisfies the specification, but theorizing like this is exactly opposite to "simple" - it would be so much harder than just learning regex. So stating that testing regex is simple is just bs. The author later confirms he is a bullshitter by his follow-up...

mFixman 2y ago

Regexes are easy to test. Bad developers do bad regexes, regardless of whether they used AI.

Etherlord87 2y ago
How do you test a regex to be 100% sure it's valid? I don't think it's possible.
- fkyoureadthedoc 2y ago
  True for most things I think
- eutropia 2y ago
  If it's using classical regex, without backtracking or other extensions, a regular expression is isomorphic to a state machine. You can enumerate combinations doing something like this: https://stackoverflow.com/a/1248566 https://stackoverflow.com/a/1248566 kids these days and their lack of exposure to finite automata
  - Etherlord87 2y ago
    - Vehicle steering is easy to test. - How so? I don't think it's possible to test for all cases... - Well, it's easy, assuming a car on a non-branching track, moving with a constant speed and without any realistic external influences on it, you can simply calculate the distance traveled using the formula s = v/t. Ah, I wish I'd stop running into fools not knowing Newton's first law of motion... - ??? Are you well?
    - loamaa 2y ago
      I understand you want to refute/diminish the parent comment on finite automata, but I think you are providing a straw man argument. The parent comment does provide an interesting, factual statement. I don't believe finite state automata are at all close in complexity to real-world self-driving car systems (or even a portion thereof). Your closing statement is also dismissive and unconstructive. I believe finite state modeling is used at NASA, A google search brings up a few references (that I'm probably not qualified to speak to), and I also remember hearing/reading a lecture on how they use them to make completely verifiable programs but can't find the exact one at the moment.
      - Etherlord87 2y ago
        I wasn't making a strawman, I was making a parody of his strawman. I thought it's obvious, since I was making an analogy, and it was an analogy to his argument.
    - eutropia 2y ago
      I should have been more clear perhaps: many regexes are capable of being verified with 100% certainty: https://en.m.wikipedia.org/wiki/Thompson%27s_construction https://en.m.wikipedia.org/wiki/Thompson%27s_construction But not all regexes (eg, those using PCRE extensions afaik) are amenable to such a treatment. Those you just tend to hope they work.
- spurgu 2y ago
  Aren't you asking how to create software without bugs?
  - Etherlord87 2y ago
    Well regex isn't Turing-complete, so it's not exactly an analysis of a program. You could reason about regex, about tokens, then describe them in a way that satisfies the specification, but theorizing like this is exactly opposite to "simple" - it would be so much harder than just learning regex. So stating that testing regex is simple is just bs. The author later confirms he is a bullshitter by his follow-up...