The opposite; case insensitivity is what human brains do, we read word WORD Word and woRD as the same thing, it's computer case-sensitive matching which is "brainless". Computers not aligning with what humans do is annoying and frustrating; they should be tools for us, not us for them. There's no way two people would write ö ö and have readers think they were different because one was written in oil-based ink and one in water-based ink, or whatever compares with behind the scenes implementation details like combining form vs single character.
Case insensitivity and "what human brains do" becomes incredibly complicated outside of English. There are also many other things which human brains recognize as the same thing but would be unreasonable to implement in filesystems.
In Japanese, くるま, クルマ, and 車 are all the same word (the first two are the phonetic spelling "kuruma", the later is the Chinese character). However in order to know that 車 is read くるま you need to be a native Japanese speaker (or have a dictionary) -- should filesystems have dictionaries to match what a human would think? Search engines that support Japanese have to handle this to some degree, but I humbly suggest implement Google Search's language handling code into a filesystem would be an ill-advised decision.
If you wanted to implement the most minimal version of this you would map between katakana and hiragana, but that means you'll need to do this for other languages. For instance, Serbian. Serbian uses two scripts (both of which have upper and lower case forms) and any native Serbian speaker would see "tuđa ljuta paprika" and "туђа љута паприка" as the same text (note that lj became љ). Should that also be automatically translated in the filesystem?
In German, capitalisation is not reversible. ß becomes SS when capitalised but will be lowercased as ss. (There is now a capital version -- ẞ -- but from what I gather it's not widely used.)
Even in English you have British and American spellings of a given word -- native speakers would recognise them as the same thing but it would not be reasonable to expect a filesystem to map them to the same thing. Initialisms can have different identical representations (N.S.A vs NSA). And you also have cases where capitalisation actually does distinguish words (May vs may, PRISM vs prism, CAT vs cat, etc). What about fullwidth and halfwidth latin characters (Ｈｅｌｌｏ vs Hello)? Arguably those are even more identical than upper and lower case.
For all of the above reasons, case insensitivity is something which most systems will only ever implement for English and a few other European languages, meaning that it's more of a wart than a fully-working feature. If the argument really is "well, a human would recognise these two names as the same thing, so the filesystem should too" then why are none of the other examples given above handled? If it's too difficult to do correctly (which is my view) then why support any of this in the first place? However, everything should be normalised (NFC or NFD depending on your usecase).
There are a couple arguments against case-insensitive filesystems I think are strong. The first is simply compatibility with existing case-sensitive systems. The second is that case is locale-dependent, so a pair of names could be equivalent or not depending on the device's locale.
I don't think I've seen any good argument against normalization, though.
I don't know about anyone else, but I read WORD as someone yelling, Word as designating/specifying a "word" with some importance, and woRD as the mocking Spongebob meme. I absolutely don't read "case insensitive" and I don't think filesystems should either.
Case can have information in it, like color and underline and boldface and italics can carry information. I think it would be clever if Google let me colour my search text and then only found text which was rendered in the same colour, but terrible if colouring my search text was mandatory and it then only found pages with text in the same colour. Likewise terrible if your code editor searched only for code with syntax highlighting matching the colours you typed in the search box.
Dog in bold, italics, red, green, uppercase, lowercase, initialcaps, smallcaps, are all the same word. What "the same" means has fuzzy boundaries and sometimes needs very precise specification, but I personally want the default to be the fuzzy convenient and the hyper-literal to be available as a fallback.
[I notice that I used 'color' and 'colour' here. My native language is UK English and programming languages and much of the internet use US English. I'm not sure if I would want `vim colour.txt` to open `color.txt`. Probably not. PowerShell 7 has a suggestions feature for "you typed a command which wasn't found, here are the most similar command names:" - mentioned in https://github.com/PowerShell/PowerShell/issues/10546 ]
> Dog in bold, italics, red, green, uppercase, lowercase, initialcaps, smallcaps, are all the same word.
But that is a feature of the word Dog, try the German words maßen (limited amounts) and massen (large amounts), historically they share the same upper case rendering MASSEN. Now someone versed in German could change to the alternative MASZEN or use the rather modern upper case version of ß. However the default naive (and most of the time correct) conversion between cases looses a significant amount of information.
Have to agree. It's also usually only about 10 lines of code to support both insensitive and sensitive searching for those who can't read English that way.
You've done the same thing here as your other comment. Here suggesting that people "can't read English" and in your other comment suggesting that people "can't get their head around capslock and don't deserve support".
What about people who CAN read English that way, but think having to match case when searching or referencing text hinders more than it helps?
Then the search tool should support not being case sensitive. I understand the efficiency of case insensitive search (otherwise Google's empire wouldn't exist).
But having it enforced as the source of all truth is just broken.
> The opposite; case insensitivity is what human brains do, we read word WORD Word and woRD as the same thing, it's computer case-sensitive matching which is "brainless".
Only if different case-variants do not have meaning. When two words that differ only in case have different meaning, we distinguish them (e.g. "moon" and "Moon").
Assuming you mean the distinction between moons in general and the Earth's Moon (Luna), if I wrote "neil armstrong was the first human to walk on the moon" would you think I meant anything other than Neil Armstrong walking on The Moon?
Meaning doesn't go when the case changes in anything like the way meaning goes when the letters change. "neil armstrong was the first human to walk on the roof" is a very different sentence, you can't get anything like that difference with just case changes. If I spoke it, you wouldn't be able to tell if I spoke the correct case or not. Would you want school children searching for "one small step for man, one giant leap for mankind" and Google says "no results" because they used a lowercase m in mankind? Would you want a TV quiz show asking "What is Europa?" and a contenstant answers "a moon of jupiter" and the host asks "do you mean moon with a capital m or lowercase m?" before they decide whether the answer is correct?
Sorry to say I tend to use case sensitivity as a filter for me offering support to other developers. I'm not willing to find time for people who can't get their head around "turn on/off caps lock". You don't do it in professional writeups or applications (and I hope not in a CV) so don't pollute my filesystems or codebases with that madness.
I’m not talking about caps lock. I can get my head around case sensitivity, I can use it, it’s worse, I don’t want to have to use it anymore than I want to use filesystem permissions in octal even though I can. Having tools take chmod u+r is easier and doesn’t change the filesystem at all.
Sorry, not sure I see the point here other than computers provide human representation of binary data?
If the mapping is non trivial then unless you're careful you end up breaking basic consistency between input and stored data hence the weird issues with mangling the unicode chars.
If the mapping is trivial theres almost nothing to discuss.
If the mapping is many to many you're going to have a bad time unless your consistent with your use of the maps.
Then the fun is broken mappings where you get data loss due to incorrect many to one and one to many mappings.
There are times when caps matter, I e. code and filesystems are human readable so should not be arbitrary, but searching these for instance makes sense to be insensitive when needed (perhaps even default)
I have just been arguing the same thing in far too much detail in this thread: https://news.ycombinator.com/item?id=29722019