Why do regexes use `$` and `^` as line anchors? (2024) (opens in new tab)

Was it a US typewriter? This peso symbol is very important in business in the US and Latin America but not, for example, England, Ireland, India, Finland, or Sweden.

> so now I just remember that "it's the opposite"

"No, the other left..."

For me it was easier to remember what ^ was, as it looks like a pointer of sorts, so felt natural it would be the beginning. Like how a string variable points to the first character.

Now that you mention it, I weirdly never struggled with this. I wonder if it's because I first started using the terminal on macOS, which I think by default starts prompts with % instead of $ or >.

Trying to consciously think about the gut-feeling that makes me remember this, all I can come up with is that $ feels "heavier" than ^, which just leads it to naturally feel like the end of a line. Perhaps its verticalness makes it feel like the vertical blinking cursor, and that's what this gut-feeling is really about? I'm not sure, the mind is a mystery sometimes haha.

I never found this hard, because $ is conventionally used at the end of many strings in Windows land (e.g. the names of network drives), which probably dates back to the CP/M dollar-terminated string.

In many dialects of BASIC (my first programming language), $ comes at the end of a variable name (e.g., NAME$) to indicate that the variable was a string (that example would often be read out loud as name-string). Remembering that, I never had to do the "it's the opposite" thing (for this case... I've done it for many other things). It's one of the few things I still remember about BASIC because I don't think I've written any ~40 years.

“Carrots (^) cost dollars ($)” is a mnemonic for the order — the carrot comes first and the dollar sign comes last.

For me, it's '^' pointing up, up being before, or first if time flows from top to bottom.

But isn't the $ usually at the end of the prompt? :)

Idk why anyone would ever "learn regex's" without the use of a look up table. It's not like timestables where having it memorized will really accelerate other aspects of life. Knowing what ^ does by memory will almost never benefit you.

Correct on the ADM3a keyboard. In fact the OP site has a pic:

https://www.hillelwayne.com/post/always-more-history/

Whether that explains the use of tilde and caret, I dont know.

^ for start of line predates the ADM3a

ASCII 1963 was the first version of the standard and it had ← https://dl.acm.org/doi/10.1145/366707.367524

The 1965 draft had _ instead https://dl.acm.org/doi/10.1145/363831.363839

The first standard edition with _ was 1968 https://www.rfc-editor.org/info/rfc20

The 1977 version is also available https://nvlpubs.nist.gov/nistpubs/Legacy/FIPS/fipspub1-2-197...

Xerox PARC used ASCII 1963 (for reasons I have yet to unearth) so its programming languages Mesa and SmallTalk used ← for assignment and camelCase to separate words in identifiers. This stylistic quirk was carried over to later object-oriented programming languages.

SHOW me the MONEY

AZERTY is primarily a French keyboard layout, to my knowledge.

The standard QWERTY layout for the number key row is `/~, 1/!, 2/@, 3/#, 4/$, 5/%, 6/^, 7/&, 8/*, 9/(, 0/), -/_, =/+. I don't know how far back the mapping of shift keys for the numbers go, but I'd be shocked if there was any around the 1960s or 1970s that put them like your AZERTY keyboard.

I think this is unlikely, as the three people involved (Deustch, Lampson, and Thompson) are all American.

Exactly what I thought of, but on querty it is the other way around.