On Sun, Apr 26, 2015 at 4:27 AM, Jerry Xiong <[email protected]> wrote:
> I even tried below code, but it still went into an infinite recursion:
> foo2=copy(foo)
Might not be generic enough but for this one, you can try
foo2 = (which(foo, (Int,))).func
> 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?
>>> >>>
>>> >>
>>>
>
