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noticed some @tech{} cleanup opportunities and added some examples

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for the random generation functionality
This commit is contained in:
Robby Findler 2016-02-21 08:27:21 -06:00
parent c4ebd771bb
commit be628e21a6
1 changed files with 23 additions and 5 deletions
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28
pkgs/racket-doc/scribblings/reference/contracts.scrbl
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@ -110,11 +110,11 @@ Contracts in Racket are subdivided into three different categories:
may hide properties of values, or even make them completely
opaque (e.g, @racket[new-∀/c]).
All contracts are impersonator contracts.}]
All @tech{contracts} are impersonator contracts.}]
For more about this hierarchy, see @tech{chaperones} and
a research paper on chaperones, impersonators, and how they can be used to
implement contracts @cite{Strickland12}.
For more about this hierarchy, see the section ``@secref["chaperones"]''
as well as a research paper @cite{Strickland12} on chaperones, impersonators,
and how they can be used to implement contracts.
@history[#:changed "6.1.1.8" @list{Changed @racket[+nan.0] and @racket[+nan.f] to
be @racket[equal?]-based contracts.}]
@ -3209,6 +3209,10 @@ it is called with @racket[#t] when there is no generator for @racket[ctc]
and called with @racket[#f] when there is a generator, but the generator
ended up returning @racket[contract-random-generate-fail].
@examples[#:eval (contract-eval) #:once
(for/list ([i (in-range 10)])
(contract-random-generate (or/c integer? #f)))]
@history[#:changed "6.1.1.5" @list{Allow @racket[fail] to accept a boolean.}]
}
@ -3219,7 +3223,21 @@ ended up returning @racket[contract-random-generate-fail].
Uses @racket[value-contract] to determine if any of the @racket[val]s have a
contract and, for those that do, uses information about the contract's shape
to poke and prod at the value. For example, if the value is function, it will
use the contract to tell it what arguments to supply to the value.
use the contract to tell it what arguments to supply to the value.
@examples[#:eval (contract-eval) #:once
(define/contract (returns-false x)
(-> integer? integer?)
(code:comment "does not obey its contract")
#f)
(eval:error (contract-exercise returns-false))
(define/contract (calls-its-argument-with-eleven f)
(-> (-> integer? integer?) boolean?)
(code:comment "f returns an integer, but")
(code:comment "we're supposed to return a boolean")
(f 11))
(eval:error (contract-exercise calls-its-argument-with-eleven))]
}
@defproc[(contract-random-generate/choose [c contract?] [fuel exact-nonnegative-integer?])