Comment by DonaldFisk
8 years ago
In addition to car and cdr, there were cpr (Contents of the Prefix part of Register) and ctr (Contents of the Tag part of Register).
> By the way, the C and R are not machine specific; any machine can have a "register"
Slight nitpick: the first machine on which I had a decent Lisp to use (Portable Standard Lisp) was a Burroughs 6800, a stack machine with no general purpose registers, or indeed any registers directly accessible by the programmer.
Vi has "registers" and so do TeX and troff. I think once upon a time, it was more common to use the word for things beside CPU registers and I/O ports.
If a cons cell is a context with two registers (R) whose contents we can access (C), the only vestiges of that IBM machine are the A and D letters sandwiched in between to distinguish them.
Compared to how option letters change meaning between Unix commands, it's nothing. -h help? Nope, h)uman readable sizes.
^ to anchor regex at beginning; $ for end. Because on common keyboards, ^ is on the right, and $ on the left!