Is there a naming convention for structs in Racket?

Question

I like the fact that there is a convention to name classes with a % suffix, because it helps differentiating instances from the higher-order class.

(define ingredient%
  (class object%
    (init-field name taste price color)
    (super-new)))

(define (total-price ingredients)
  (for/sum (ingredient ingredients)
    ;; here "ingredient" stands for the instance, not the class ingredient%
    (get-field price ingredient)))

---

In the other hand, when I need a struct, I'm struggling to find names for instances that don't collide with the struct name.

(struct ingredient (name taste price color))

(define (total-price ingredients)
  (for/sum (igrdt ingredients)
    ;; igrdt is definitely a bad name
    (ingredient-price igrdt)))

;; it looks even worse in arguments
(define (taste igrdt)
  (match (ingredient-taste igrdt)
    (('good) "It's good!")
    (('bad) "Yuk...")
    (else "It's something.")))

---

So I started using a suffix for structs too: §. The symbol is easily accessible on my keyboard, alas maybe not on a standard QWERTY one, so I guess I'll change it to $ later on.

(struct ingredient§ (name taste price color))
(define ingredient (ingredient§ "Carrot" 'good 1.0 'orange))
(displayln (format "I'm making a ~a cake." (ingredient§-name ingredient)))

Whatever the symbol, I find that using a suffix for structs keeps you free to choose clear instance names instead of having to remove random vowels from your variables.

Another option would be to use % as a prefix for structs and as a suffix for classes, so that struct accessors stay readable: (%ingredient-name ingredient).

Judging from a quick GitHub research: https://github.com/search?p=1&q=struct-out+language%3Aracket&type=Code

It looks like everyone is pretty much using structs as-is (except a few students using CamelCase because they're used to it).

So what can I do to differentiate instances from a struct type? Is it even relevant? Am I thinking to far? Should I ask this on Software Engineering?

Answer 1

The naming convention is that structs don't have a special notation. This may be due to struct being more 'scheme like' than classes, units, signatures, components, etc. but I could be wrong.

There's nothing wrong with inventing something for struct similar to classes, units, etc. But it will arbitrary and personal and therefore it should probably be documented.