I even tried below code, but it still went into an infinite recursion:
foo2=copy(foo)
function foo(X::Int)
@assert(X>=0,"X should be a positive number.")
foo2(X)
end
Since the copy or deepcopy can not really copy a function but still just be
a reference of it.
On Sunday, April 26, 2015 at 10:22:34 AM UTC+2, Jerry Xiong wrote:
>
> Yes. I tried it, and it indeed went into an infinite recursion.
>
> On Sunday, April 26, 2015 at 10:06:57 AM UTC+2, Mauro wrote:
>>
>> > Thank you! For this question, invoke indeed a good solution :)
>> >
>> > How about a more general case. For example, I already have a function
>> foo
>> > foo(X::Int)=X+1
>> > in the environment.
>> >
>> > Then I want to overload foo to forbid negative input:
>> > function foo(X::Int)
>> > @assert(X>=0,"X should be a positive number.")
>> > invoke(foo,(Int,),X)#Here, I hope to call the original definition
>> of
>> > foo.
>> > end
>> >
>> > However, invoke doesn't work as I expected in this case. Is there any
>> other
>> > solution?
>>
>> I don't think there is. There can only be one method for each signature
>> for one generic function. So above gets you into an infinite recursion.
>>
>> > On Sunday, April 26, 2015 at 8:40:06 AM UTC+2, Sam L wrote:
>> >>
>> >> See ?invoke.
>> >>
>> >> display(X::Vector)=length(X)>10?print("Too long to show."):
>> >> invoke(display, (Any,), X)
>> >>
>> >> On Saturday, April 25, 2015 at 10:41:39 PM UTC-7, Jerry Xiong wrote:
>> >>>
>> >>> For example, if I want to overload the Base.display(::Vector) to
>> repress
>> >>> the display when the vector is too long, I coded as below:
>> >>> julia> import Base.display
>> >>>
>> >>> julia> display(X::Vector)=length(X)>10?print("Too long to
>> show."):Base.
>> >>> display(X)
>> >>> display (generic function with 17 methods)
>> >>>
>> >>> julia> display([1,2,3])
>> >>> ERROR: stack overflow
>> >>> in display at none:1 (repeats 39998 times)
>> >>>
>> >>> I want to call the original Base.display when the length of vector is
>> >>> less than 10, but it is became a dead recurring. Is there any way to
>> do it?
>> >>>
>> >>
>>
>>
