Version: 5.0
12 Structs
| (require unstable/struct) |
This library is unstable;
compatibility will not be maintained.
See Unstable for more information.
| (make struct-id expr ...) |
Creates an instance of struct-id, which must be bound as a
struct name. The number of exprs is statically checked
against the number of fields associated with struct-id. If
they are different, or if the number of fields is not known, an error
is raised at compile time.
Examples: |
| > (define-struct triple (a b c)) |
| > (make triple 3 4 5) |
#<triple> |
| > (make triple 2 4) |
eval:4:0: make: wrong number of arguments for struct triple |
(expected 3, got 2) in: (make triple 2 4) |
| (struct->list v [#:on-opaque on-opaque]) → (or/c list? #f) |
| v : any/c |
| on-opaque : (or/c 'error 'return-false 'skip) = 'error |
Returns a list containing the struct instance v’s
fields. Unlike struct->vector, the struct name itself is not
included.
If any fields of v are inaccessible via the current inspector the behavior of struct->list is determined by on-opaque. If on-opaque is 'error (the default), an error is raised. If it is 'return-false, struct->list returns #f. If it is 'skip, the inaccessible fields are omitted from the list.
Examples: |
| > (define-struct open (u v) #:transparent) |
| > (struct->list (make-open 'a 'b)) |
'(a b) |
| > (struct->list #s(pre 1 2 3)) |
'(1 2 3) |
| > (define-struct (secret open) (x y)) |
| > (struct->list (make-secret 0 1 17 22)) |
struct->list: expected argument of type <non-opaque |
struct>; given (secret 0 1 ...) |
| > (struct->list (make-secret 0 1 17 22) #:on-opaque 'return-false) |
#f |
| > (struct->list (make-secret 0 1 17 22) #:on-opaque 'skip) |
'(0 1) |
| > (struct->list 'not-a-struct #:on-opaque 'return-false) |
#f |
| > (struct->list 'not-a-struct #:on-opaque 'skip) |
'() |