https://buttondown.email/hillelwayne/archive/why-do-regexes-use-and-as-line-anchors/
Last week I fell into a bit of a rabbit hole: why do regular expressions use $ and ^ as line anchors?1
This talk brings up that they first appeared in Ken Thompson's port of the QED text editor. In his manual he writes: b) "^" is a regular expression which matches character at the beginning of a line.
c) "$" is a regular expression which matches character before the character (usually at the end of a line)
QED was the precursor to ed, which was instrumental in popularizing regexes, so a lot of its design choices stuck.
Okay, but then why did Ken Thompson choose those characters?
(Score: 2) by krishnoid on Thursday March 28 2024, @09:21PM
Designers are probably trained for traditional print media, and something that describes layouts and floats using declarative and markup languages is probably going to require a GUI for them to be able to do their thing. They're not coders, after all.