Or come to think of it would generalizing value types like (-val ‘null) in this
case to for instance Symbol also fix cases like this?
On Jan 19, 2015, at 10:09 AM, Alexander D. Knauth <alexan...@knauth.org> wrote:
> If there was a way to convert a “value” type to a more general type, for
> instance convert all hash-table value types to HashTableTop, or vector value
> types to VectorTop, etc. and then use (not (or (subtype t1 t2) (subtype t2
> t1))) or something like that, could that catch cases like this?
>
> On Jan 19, 2015, at 9:58 AM, Sam Tobin-Hochstadt <sa...@cs.indiana.edu> wrote:
>
>> On Mon, Jan 19, 2015 at 9:54 AM, Alexander D. Knauth
>> <alexan...@knauth.org> wrote:
>>> Would there be a more general solution that wouldn’t be specific to just
>>> hash-tables?
>>
>> I'm not sure what you mean. The code you suggested fixes a
>> hash-table-specific limitation in Typed Racket. If the question is
>> could `overlap` not have so many cases, then I'd certainly like that,
>> but it's very hard to accomplish. In particular, abstractions like
>> `Sequence` and `Evt` overlap with arbitrarily many types. A more
>> principles treatment of such abstractions would help, but we don't yet
>> know how to do that.
>>
>> Sam
>>
>>>
>>> On Jan 19, 2015, at 9:38 AM, Sam Tobin-Hochstadt <sa...@cs.indiana.edu>
>>> wrote:
>>>
>>>> This is a correct improvement to Typed Racket -- I'll make it shortly.
>>>>
>>>> Sam
>>>>
>>>> On Mon, Jan 19, 2015 at 8:41 AM, Alexander D. Knauth
>>>> <alexan...@knauth.org> wrote:
>>>>> I managed to fix this for your example by inserting these 3 lines into
>>>>> typed-racket/types/remove-intersect.rkt after line 67:
>>>>> [(list-no-order (Value: (not (? hash?)))
>>>>> (or (? Hashtable?) (? HashtableTop?)))
>>>>> #f]
>>>>> There is probably a better solution though.
>>>>>
>>>>> On Jan 19, 2015, at 7:36 AM, Alexander D. Knauth <alexan...@knauth.org>
>>>>> wrote:
>>>>>
>>>>> Since hash-tables can be mutable as far as TR knows, (HashTable Symbol
>>>>> String) is not a subtype of (HashTable Symbol JSExpr).
>>>>> To work around this, you can do this:
>>>>> #lang typed/racket/base
>>>>> (require typed/json)
>>>>> (: jsx JSExpr) ; <-- jsx is what I ultimately want.
>>>>> (define jsx (ann #hasheq((a . "val1") (b . "val2") (c . "val3"))
>>>>> (HashTable
>>>>> Symbol JSExpr)))
>>>>>
>>>>> Or this would work too:
>>>>> #lang typed/racket/base
>>>>> (require typed/json)
>>>>> (: jsx (HashTable Symbol JSExpr)) ; <-- jsx is what I ultimately
>>>>> want.
>>>>> (define jsx #hasheq((a . "val1") (b . "val2") (c . "val3")))
>>>>>
>>>>> Or you could use (inst make-immutable-hasheq Symbol JSExpr) instead of
>>>>> using
>>>>> #hasheq, and it would do the same thing.
>>>>>
>>>>>
>>>>> On Jan 19, 2015, at 1:28 AM, Jordan Johnson <j...@fellowhuman.com> wrote:
>>>>>
>>>>> Hi all,
>>>>>
>>>>> I’ve been trying to create JSExprs, as defined in the typed/json library.
>>>>> This is one of those instances where it seems like I must be making things
>>>>> harder than they should be, but I’m still feeling like a duck on
>>>>> rollerskates in TR, so I want to make sure I’m not missing an easier way
>>>>> to
>>>>> do it.
>>>>>
>>>>> Would you please confirm if this is indeed a smallest-possible solution?
>>>>>
>>>>> ;;;; begin
>>>>> #lang typed/racket/base
>>>>>
>>>>> (require typed/json)
>>>>>
>>>>> (: jsx JSExpr) ; <-- jsx is what I ultimately want.
>>>>>
>>>>> ;; Attempt #1:
>>>>> #;
>>>>> (define jsx #hasheq((a . "val1") (b . "val2") (c . "val3")))
>>>>>
>>>>> #| Resulting error:
>>>>> Type Checker: type mismatch
>>>>> expected: JSExpr
>>>>> given: (HashTable Symbol String)
>>>>>
>>>>> [This seems weird, since it seems like (HashTable Symbol String) should be
>>>>> a subtype of JSExpr. Is the problem that the typechecker can’t recognize
>>>>> the Strings as JSExprs?]
>>>>> |#
>>>>>
>>>>> ;; Attempt #N (shortest successful version I’ve found):
>>>>> (define jsx
>>>>> (for/hasheq : (HashTable Symbol JSExpr) ([k '(a b c)]
>>>>> [v '("val1" "val2" "val3")])
>>>>> (values k v)))
>>>>> ;;;; end
>>>>>
>>>>> Regards,
>>>>> Jordan
>>>>>
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>
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