suzanne.soy/typed-racket
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Add doc examples for the struct form

Browse Source
This commit is contained in:
Asumu Takikawa 2015-03-11 13:41:14 -04:00
parent 238e76b63f
commit 61b8e098e6
1 changed files with 19 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
typed-racket-doc/typed-racket/scribblings/reference/special-forms.scrbl
View File

@ -382,19 +382,36 @@ those functions.
fields @racket[f] have types @racket[t], similar to the behavior of @|struct-id|
from @racketmodname[racket/base].
When @racket[parent] is present, the
structure is a substructure of @racket[parent]. When
@racket[maybe-type-vars] is present, the structure is polymorphic in the type
structure is a substructure of @racket[parent].
@ex[
(struct camelia-sinensis ([age : Integer]))
(struct camelia-sinensis-assamica camelia-sinensis ())
]
When @racket[maybe-type-vars] is present, the structure is polymorphic in the type
variables @racket[v]. If @racket[parent] is also a polymorphic struct, then
there must be at least as many type variables as in the parent type, and the
parent type is instantiated with a prefix of the type variables matching the
amount it needs.
@ex[
(struct (X Y) 2-tuple ([first : X] [second : Y]))
(struct (X Y Z) 3-tuple 2-tuple ([first : X] [second : Y] [third : Z]))
]
Options provided have the same meaning as for the @|struct-id| form
from @racketmodname[racket/base].
A prefab structure type declaration will bind the given @racket[name] to a
@racket[Prefab] type. Unlike in @racketmodname[racket/base], a non-prefab
structure type cannot extend a prefab structure type.
@ex[
(struct a-prefab ([x : String]) #:prefab)
(:type a-prefab)
(struct not-allowed a-prefab ())
]
}