I agree, the docs could be a lot clearer. I'll add examples that use keyword arguments.
Thanks for the report! Vincent At Thu, 21 Feb 2013 09:18:39 +0000, Norman Gray wrote: > > > Neil, hello. > > On 2013 Feb 21, at 03:49, Neil Toronto <neil.toro...@gmail.com> wrote: > > > Well, you can't do it like that, but you can like this: > > > > #lang typed/racket > > > > (: test0 (Integer [#:zero Integer] -> Boolean)) > > (define (test0 x #:zero [v 0]) > > (= x v)) > > Aha -- that's certainly a neater way of doing it. Thanks! > > There may be a documentation lacuna, however, since that form seems to be not > straightforwardly deducible from the Typed Racket reference (v5.3.3). > > Section 1.6, Other Type Constructors > <http://docs.racket-lang.org/ts-reference/type-ref.html#%28part._.Other_.Type_.Constructors%29>, > describes four forms of function type, but doesn't include any optional > arguments (I presumed that such optional parts had to be typed explicitly > with case->). 'dom' isn't defined there (I guessed it could refer only to an > individual type), and the 'dom' of > <http://docs.racket-lang.org/reference/function-contracts.html> doesn't > match. Even the 'optional-dom' of the ->* description doesn't fit the form > above. > > Similarly, the opt-lambda: of > <http://docs.racket-lang.org/ts-reference/special-forms.html#(part._.Anonymous_.Functions)> > includes optional arguments, but doesn't appear to permit keywords. > > The (Integer [#:zero Integer] -> Boolean) form is pretty intuitive, though, > and I should have experimented more, but I confess to being an incorrigible > obsessive about manuals (new fridge, new phone: "Oh, look, what nice manual, > I'll turn the gadget on later..."). > > All the best, > > Norman > > > -- > Norman Gray : http://nxg.me.uk > SUPA School of Physics and Astronomy, University of Glasgow, UK > > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
