4 ms·

Common Lisp Wiki: Naming Conventions

81 points by susam 4y ago

uncletaco 4y ago
I am and forever will be a fan of the scheme (and now clojure) convention of saying foo->bar to say foo to bar. I just think that's swell.
- ruricolist 4y ago
  The CL convention would be to have a function called bar that converts whatever its argument into an instance of bar. Make it generic and new libraries can easily add their own conversions for their own data types.
  - lisper 4y ago
    My personal convention is to call such a generic function ->bar to make it clear that what it does is coerce its argument to a different type.
- vats 4y ago
  > I am and forever will be a fan of the scheme (and now clojure) convention of saying foo->bar to say foo to bar. I just think that's swell. In his book—Lisp in Small Pieces—Christian Quienec suggests using a reversed arrow (ie. bar<-foo) so the direction of the arrow agrees with the evaluation order in a function composition. eg. (foo<-bar (bar<-foo ...)), which would have otherwise been (bar->foo (foo->bar ...)).
  - nlitened 4y ago
    In Clojure you're likely to use an arrow to do multiple compositions, eg. (-> foo foo->bar bar->baz)
  - dunefox 4y ago
    That's quite nice.
  - mncharity 4y ago
    > bar<-foo Or bar_from_foo , when identifier charsets prohibit <- .
- nemoniac 4y ago
  Actually I'm more of a fan of bar<-foo because you can line them up like: (bar<-foo (foo<-baz (baz<-quux thing))) instead of: (foo->bar (baz->foo (quux->baz thing)))
  - narimiran 4y ago
    But you can do composition, like this: [Racket] (~> thing quux->baz baz->foo foo->bar)
wibblewobble124 4y ago
Scheme also abbreviates: call-with-current-continuation To call/cc The forward slash serving the purpose of “with”.
djhaskin987 4y ago
As I've been slowly learning Common Lisp, I'm fascinated by how much Rich Hickey took from the CL community in making Clojure. For example, the names in embedded languages starting with `?`. He uses this naming convention all the time in the datomic docs[1] showing how to query the database. 1: https://docs.datomic.com/on-prem/query/query.html https://docs.datomic.com/on-prem/query/query.html
- lispm 4y ago
  See for example the Prolog implementation in PAIP: https://github.com/norvig/paip-lisp/blob/main/docs/chapter11.md https://github.com/norvig/paip-lisp/blob/main/docs/chapter11... But I would think the convention is quite a bit older than Common Lisp and earlier Lisp programs should have used something like that to notate variables in special sublanguages (especially in simple Prolog variants or in Rule-based systems).
nulbyte 4y ago
> These will annoy people: ... hungarian-identifiers-pcsnsi What does this mean? I have no idea what pcsnsi is, or why this is "Hungarian."
- Jtsummers 4y ago
  It's a reference to Hungarian notation which had two forms, systems and apps. Systems notation would prefix variables with their primitive type: long lTime; bool bPrint; Apps notation would prefix variables with something conveying a domain-specific semantic element: point ptPlayer; You aren't supposed to know what pcsnsi means because it is just a nonsense string here, but presumably has some potential apps notation meaning if used in the real world. https://en.wikipedia.org/wiki/Hungarian_notation https://en.wikipedia.org/wiki/Hungarian_notation
gibsonf1 4y ago
For predicates, I’ve abandoned the p postfix as it’s then so hard to know which predicates you have. Instead we now use the ? as a prefix to any Boolean predicate, so in the repl you can just type ? Hit tab and see all available predicates.

81 points by susam 4y ago

I am and forever will be a fan of the scheme (and now clojure) convention of saying foo->bar to say foo to bar. I just think that's swell.

ruricolist 4y ago
The CL convention would be to have a function called bar that converts whatever its argument into an instance of bar. Make it generic and new libraries can easily add their own conversions for their own data types.
- lisper 4y ago
  My personal convention is to call such a generic function ->bar to make it clear that what it does is coerce its argument to a different type.
vats 4y ago
> I am and forever will be a fan of the scheme (and now clojure) convention of saying foo->bar to say foo to bar. I just think that's swell. In his book—Lisp in Small Pieces—Christian Quienec suggests using a reversed arrow (ie. bar<-foo) so the direction of the arrow agrees with the evaluation order in a function composition. eg. (foo<-bar (bar<-foo ...)), which would have otherwise been (bar->foo (foo->bar ...)).
- nlitened 4y ago
  In Clojure you're likely to use an arrow to do multiple compositions, eg. (-> foo foo->bar bar->baz)
- dunefox 4y ago
  That's quite nice.
- mncharity 4y ago
  > bar<-foo Or bar_from_foo , when identifier charsets prohibit <- .
nemoniac 4y ago
Actually I'm more of a fan of bar<-foo because you can line them up like: (bar<-foo (foo<-baz (baz<-quux thing))) instead of: (foo->bar (baz->foo (quux->baz thing)))
- narimiran 4y ago
  But you can do composition, like this: [Racket] (~> thing quux->baz baz->foo foo->bar)

wibblewobble124 4y ago

Scheme also abbreviates: call-with-current-continuation To call/cc The forward slash serving the purpose of “with”.

djhaskin987 4y ago

As I've been slowly learning Common Lisp, I'm fascinated by how much Rich Hickey took from the CL community in making Clojure. For example, the names in embedded languages starting with `?`. He uses this naming convention all the time in the datomic docs[1] showing how to query the database. 1: https://docs.datomic.com/on-prem/query/query.html https://docs.datomic.com/on-prem/query/query.html

lispm 4y ago
See for example the Prolog implementation in PAIP: https://github.com/norvig/paip-lisp/blob/main/docs/chapter11.md https://github.com/norvig/paip-lisp/blob/main/docs/chapter11... But I would think the convention is quite a bit older than Common Lisp and earlier Lisp programs should have used something like that to notate variables in special sublanguages (especially in simple Prolog variants or in Rule-based systems).

nulbyte 4y ago

> These will annoy people: ... hungarian-identifiers-pcsnsi What does this mean? I have no idea what pcsnsi is, or why this is "Hungarian."

Jtsummers 4y ago
It's a reference to Hungarian notation which had two forms, systems and apps. Systems notation would prefix variables with their primitive type: long lTime; bool bPrint; Apps notation would prefix variables with something conveying a domain-specific semantic element: point ptPlayer; You aren't supposed to know what pcsnsi means because it is just a nonsense string here, but presumably has some potential apps notation meaning if used in the real world. https://en.wikipedia.org/wiki/Hungarian_notation https://en.wikipedia.org/wiki/Hungarian_notation

gibsonf1 4y ago

For predicates, I’ve abandoned the p postfix as it’s then so hard to know which predicates you have. Instead we now use the ? as a prefix to any Boolean predicate, so in the repl you can just type ? Hit tab and see all available predicates.