3 ms·

"FLPL, for mysterious reasons, used pretty horrible names like XCARF and XCDRF" It's not mysterious at all, these were also named after the 704 register scheme

"FLPL, for mysterious reasons, used pretty horrible names like XCARF and XCDRF" It's not mysterious at all, these were also named after the 704 register scheme. Your argument that MacCarthy et al couldn't think of accurate names may be valid (naming is one of the hardest things, after all), but there are certainly 'better' names, so more likely these just stuck after the initial implementations. "so a pattern similar to cadr, cddr ... is possible." Honestly, these are abominations. Remember the point of high level languages etc is not just so you can write code as fast as possible, but that someone else (maybe your future self) can read and understand it easily.

kazinator 3y ago
> It's not mysterious at all By that remark, I'm referring to the X...F dirt in XCARF, not to the CAR infix that we all understand. Why the authors of FLPL saddled the identifiers with that is puzzling. (Extract the content of the address part of the register function? Why?) Regarding that "R" in car, though standing for "register", refers to a register in memory; Aontent of the Address part of the Register cell. A piece of memory can be called a register today (e.g. virtual machines have registers that are actually in memory, and some processors have had memory mapped registers like zero page on the 6502). "Content" continues to apply. If someone doesn't like "register", they can pretend it stands for "record". CAR: content of the A part of the record; CDR: content of the D part of the record. The only weird thing are the choices of A and D; the "address" and "data" interpretations don't make sense. But they are just one letter out of three. Why does it have to be English? A = antérieur D = derrière In English we use Latin-derived prefixes where A and D form opposite pairs, like: Ascend/Descend; Approve/Disapprove; Adduce/Deduce .. Or cases where we have different roots: Arrive/Depart. Maybe some interpretation can be found. In Japanese, car and cdr as the verbs "karu" and "kudaru" work. There are several verbs spelled "karu": 刈る (cut, mow, clip, ...), 借る (borrow) and some others like 狩る (hunt: animals, but also refers to picking and gathering berries and such). Kudaru is 下る, to descend. We can borrow/clip/pick the item at this cell (karu) or descend down (kudaru) to the next cell. Not everyone who codes is a native speaker, yet most languages use English-derived words. Someone to whom "if" and "while" are foreign words may not care about some English speakers nitpicking over car and cdr. > can read and understand it easily. If you accept (car (cdr (cdr x))), then (caddr x) is a nice abbreviation for it, related by a transparent naming scheme. The source code is smaller, and if the compiler doesn't automatically reduce (car (cdr (cdr x))) to caddr, you get better code density. The name doesn't work in a filter pipeline (-> x caddr ...) because the letters are now backwards w.r.t. pipe direction, since they indicate right to left application. A good way for your future self to understand everything is not to keep changing names every year. The future self of some person coding in 1968 understands (if still alive) code I just wrote in a different Lisp dialect in 2023, because I used (cadr x). It may not be familiar to Lisp outsiders, but it's an utterly unmoving target for insiders.

kazinator 3y ago

> It's not mysterious at all By that remark, I'm referring to the X...F dirt in XCARF, not to the CAR infix that we all understand. Why the authors of FLPL saddled the identifiers with that is puzzling. (Extract the content of the address part of the register function? Why?) Regarding that "R" in car, though standing for "register", refers to a register in memory; Aontent of the Address part of the Register cell. A piece of memory can be called a register today (e.g. virtual machines have registers that are actually in memory, and some processors have had memory mapped registers like zero page on the 6502). "Content" continues to apply. If someone doesn't like "register", they can pretend it stands for "record". CAR: content of the A part of the record; CDR: content of the D part of the record. The only weird thing are the choices of A and D; the "address" and "data" interpretations don't make sense. But they are just one letter out of three. Why does it have to be English? A = antérieur D = derrière In English we use Latin-derived prefixes where A and D form opposite pairs, like: Ascend/Descend; Approve/Disapprove; Adduce/Deduce .. Or cases where we have different roots: Arrive/Depart. Maybe some interpretation can be found. In Japanese, car and cdr as the verbs "karu" and "kudaru" work. There are several verbs spelled "karu": 刈る (cut, mow, clip, ...), 借る (borrow) and some others like 狩る (hunt: animals, but also refers to picking and gathering berries and such). Kudaru is 下る, to descend. We can borrow/clip/pick the item at this cell (karu) or descend down (kudaru) to the next cell. Not everyone who codes is a native speaker, yet most languages use English-derived words. Someone to whom "if" and "while" are foreign words may not care about some English speakers nitpicking over car and cdr. > can read and understand it easily. If you accept (car (cdr (cdr x))), then (caddr x) is a nice abbreviation for it, related by a transparent naming scheme. The source code is smaller, and if the compiler doesn't automatically reduce (car (cdr (cdr x))) to caddr, you get better code density. The name doesn't work in a filter pipeline (-> x caddr ...) because the letters are now backwards w.r.t. pipe direction, since they indicate right to left application. A good way for your future self to understand everything is not to keep changing names every year. The future self of some person coding in 1968 understands (if still alive) code I just wrote in a different Lisp dialect in 2023, because I used (cadr x). It may not be familiar to Lisp outsiders, but it's an utterly unmoving target for insiders.