You need to fully specify TDict when using it's constructor:
~~~
julia> module testnestparam2
immutable Token{S,T}
m::S
t::T
end
typealias TDict{K,D} Token{Dict{K,D}, Int}
function makeADict()
a = TDict{Int64,String}([1=>"a",2=>"c"], 5)
end
end
Warning: replacing module testnestparam2
julia> testnestparam2.makeADict()
Token{Dict{Int64,String},Int64}([2=>"c",1=>"a"],5)
~~~
On Tue, Oct 7, 2014 at 11:41 AM, <[email protected]> wrote:
> Oops, sorry, in my last posting there was obviously an error in my code
> because I used the wrong syntax to call an array constructor. Here is
> another example where now I am using the correct constructor syntax (I
> think?). But I still get the same error message concerning 'apply'.
>
> module testnestparam2
>
> immutable Token{S,T}
> m::S
> t::T
> end
>
> typealias TDict{K,D} Token{Dict{K,D}, Int}
>
> function makeADict()
> a = TDict([1=>"a",2=>"c"], 5)
> end
>
> end
>
>
>
>
>
>
>
>
>
>
> On Tuesday, October 7, 2014 12:29:49 PM UTC-4, [email protected] wrote:
>>
>> Here is a very short Julia code that gives a mysterious error message in
>> the latest build (952). Is it an error in my code or a bug in Julia? (In
>> addition to the answer to this question, I would also like help with the
>> code design question in my previous posting of two hours ago.)
>>
>> Thanks,
>> Steve
>>
>> module testnestparam2
>>
>> typealias ADict{K,D} Array{Dict{K,D},1}
>>
>> function makeADict()
>> a = ADict([[-9=>"a"],[15=>"b"]]) #line 6
>> println("a[1][-9] = ", a[1][-9])
>> end
>>
>> end
>>
>> julia> testnestparam2.makeADict()
>> ERROR: type: makeADict: in apply, expected Function, got
>> Type{Array{Dict{K,D},1
>> }
>> in makeADict at c:\Users\vavasis\Documents\Projects\qmg21\julia\
>> testnestparam2
>> jl:6
>>
>>
>>
>> On Tuesday, October 7, 2014 10:05:09 AM UTC-4, [email protected] wrote:
>>>
>>> Thanks for the explanation! Although I think I understand your answer,
>>> I'm not sure how to define the types to accomplish my goal.
>>>
>>> * a Token should have two parts, a container and a semitoken, both
>>> abstract
>>>
>>> * an SDToken should be a specialization of Token in which the container
>>> portion is SortedDict{K,D} for a specific K,D and the semitoken portion is
>>> IntSemiToken (both parts concrete)
>>>
>>> * Some functions take SDToken's as input. These should be generic,
>>> i.e., work for all choices of K,D.
>>>
>>> * There are also generic functions that return SDTokens as output (in
>>> which K and D are determined from the input args).
>>>
>>> Can I write typealias SDToken{K,D} Token{SortedDict{K,D},IntSemiToken}?
>>> I tried this and got an unexpected error message:
>>>
>>> ERROR: type: test1: in apply, expected Function, got
>>> Type{Token{SortedDict{K,D},
>>> IntSemiToken}}
>>> in test1 at c:\Users\vavasis\Documents\Projects\qmg21\julia\
>>> testnestparam.jl:32
>>>
>>> (No 'apply' in my code!) And in any case, even if I could write this,
>>> I'm not sure it solves the problem.
>>>
>>> -- Steve
>>>
>>>
>>>
>>> On Tuesday, October 7, 2014 2:15:01 AM UTC-4, Jutho wrote:
>>>>
>>>> I don't see the problem regarding point one.
>>>>
>>>> A type with parameters, as your SortedDict{D,K}, becomes an abstract
>>>> type when the parameters are unspecified, e.g. SortedDict, but this is
>>>> indeed printed/formatted with unspecified parameters put back (I guess with
>>>> the name as you defined them), e.g. as SortedDict{D,K}.
>>>>
>>>> Regarding point 2, this relates to the invariance of parametric types.
>>>>
>>>> isa(t2,Token{SortedDict, IntSemiToken})
>>>> will return false, because
>>>> Token{SortedDict{Int64,ASCIIString},IntSemiToken} <: Token{SortedDict,
>>>> IntSemiToken}
>>>> is false. There are many discussions regarding this both on the forum
>>>> and I guess in the manual. Search for invariance versus covariance of
>>>> parametric types.
>>>>
>>>>
>>>> Op dinsdag 7 oktober 2014 04:42:12 UTC+2 schreef [email protected]:
>>>>>
>>>>> The code below is an excerpt from a more complicated code I am
>>>>> writing. It contains a parametrized type in which the parameter is itself
>>>>> another parametrized type. I have attached the printout (0.4.0-dev+323).
>>>>> Notice the error message at the end. My questions are:
>>>>>
>>>>> (1) How is it possible that the type of t includes dummy parameters K
>>>>> and D, which aren't real types at all?
>>>>>
>>>>> (2) Why is Julia not able to match t2 but it is able to match t to the
>>>>> signature of test0()?
>>>>>
>>>>> Thanks,
>>>>> Steve Vavasis
>>>>>
>>>>>
>>>>> julia> testnestparam.test1()
>>>>> typeof(t) = Token{SortedDict{K,D},IntSemiToken}
>>>>> typeof(t2) = Token{SortedDict{Int64,ASCIIString},IntSemiToken}
>>>>> methods(test0) = # 1 method for generic function "test0":
>>>>> test0(i::Token{SortedDict{K,D},IntSemiToken}) at
>>>>> c:\Users\vavasis\Documents\Projects\qmg21\julia\testnestparam.jl:28
>>>>> ERROR: `test0` has no method matching test0(::Token{SortedDict{
>>>>> Int64,ASCIIString},IntSemiToken})
>>>>> in test1 at c:\Users\vavasis\Documents\Projects\qmg21\julia\
>>>>> testnestparam.jl:38
>>>>>
>>>>>
>>>>> module testnestparam
>>>>>
>>>>> immutable IntSemiToken
>>>>> address::Int
>>>>> end
>>>>>
>>>>> immutable Token{T, S}
>>>>> container::T
>>>>> semitoken::S
>>>>> end
>>>>>
>>>>> # take a token apart
>>>>> semi(i::Token) = i.semitoken
>>>>> container(i::Token) = i.container
>>>>>
>>>>> # put a token back together
>>>>> assemble(m, s) = Token(m,s)
>>>>>
>>>>> type SortedDict{K, D} <: Associative{K,D}
>>>>> bt::Dict{K,D}
>>>>> end
>>>>>
>>>>> typealias SDToken Token{SortedDict, IntSemiToken}
>>>>>
>>>>> sdtoken_construct(m::SortedDict,int1::Int) =
>>>>> SDToken(m, IntSemiToken(int1))
>>>>>
>>>>> test0(i::SDToken) = nothing
>>>>>
>>>>> function test1()
>>>>> s = SortedDict([1=>"a",2=>"b"])
>>>>> t = sdtoken_construct(s, 0)
>>>>> t2 = assemble(t.container, t.semitoken)
>>>>> println("typeof(t) = ", typeof(t))
>>>>> println("typeof(t2) = ", typeof(t2))
>>>>> println("methods(test0) = ", methods(test0))
>>>>> test0(t)
>>>>> test0(t2) #Line 38
>>>>> end
>>>>>
>>>>> end
>>>>>
>>>>>
