The default value is considered "inside" the contract boundary, not outside.
Robby On Sun, Aug 24, 2014 at 2:17 AM, Kevin Forchione <[email protected]> wrote: > > On Aug 23, 2014, at 10:03 PM, Kevin Forchione <[email protected]> wrote: > > I’ve been trying to figure out the syntax for optional keywords in the ->i > contract form. For example: > > (->i ([lst list?]) > ([#:foo ….]) ; what does this look like? > (result list?)) > > The mandatory domain syntax seems straightforward, but I’ve tried various > combinations for the optional keyword that don’t appear to be correct. > > (->i ([lst list?]) > ([#:foo (lst) (….etc))) > (result list?)) > > doesn’t work for me, neither does sticking an id before or after … (lat) … > > Does anyone have an example of an optional keyword ->i contract? This would > seem to be an extremely useful form, but the examples in the documentation > do not appear to cover it. They do cover the ->* form, but not the ->i for > that combination. > > > Well, I seem to have sussed it. But I find it odd that the contract doesn’t > appear to apply to the optional value as supplied. For example, the below > shows a sample of ->*, and an ->i version that shows points up the issue: > > #lang racket > > (define/contract (foo x #:y y #:z (z 42)) > (->* (integer? > #:y integer?) > (#:z integer?) > list?) > (list x y z)) > > (foo 3 #:y 1) > > (define/contract (bar x #:y y #:z (z 42)) > (->i ([x integer?] > #:y (y integer?)) > (#:z (z (x y) (integer-in x y))) > (result list?)) > (list x y z)) > > (bar 3 #:y 5) > (bar 3 #:y 5 #:z 4) > > -Kevin > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users > ____________________ Racket Users list: http://lists.racket-lang.org/users
