On Sun, May 31, 2015 at 8:48 AM, Tom Lee <m...@tomlee.id.au> wrote:
> No, in that example you create an anonymous function. I'm not certain on the
> semantics, but "n" effectively points to this nameless function. Anonymous
> functions are not as fast as "generic" ones (at least in 0.3, at least
> sometimes) and you cannot add new methods to them for multiple dispatch (as
> far as I know).
>
> Also, I should clarify that when I wrote "My understanding is that you
> should never use a macro if you can easily write an equivalent function" I
> meant you should not create a new macro to do something that can just as
> easily be done by a function - not that existing macros like @eval should be
> avoided.
>
> On Sunday, 31 May 2015 21:45:46 UTC+10, Kevin Squire wrote:
>>
>> Actually, it's name is "n":
>>
>> julia> function getfn()
>> return function(); 1; end
>> end
>> getfn (generic function with 1 method)
>>
>> julia> const n = getfn()
>> (anonymous function)
Well, it's anonymous as shown here.
If you just want to give that function a name (i.e. make it a generic function).
```julia
julia> function getfn()
f() = 1
end
getfn (generic function with 1 method)
julia> getfn()
f (generic function with 1 method)
```
This function is defined in the `getfn()` local scope and is not
extending a global function with the same name nor is it bound to a
global function for extending.
Unless you want to define a closure, @eval is probably want you want.
>>
>> julia> n()
>> 1
>>
>>
>>
>> On Sat, May 30, 2015 at 5:09 PM, David P. Sanders <dpsa...@gmail.com>
>> wrote:
>>>
>>>
>>>
>>> El domingo, 31 de mayo de 2015, 0:37:45 (UTC+2), Jameson escribió:
>>>>
>>>> But "@eval" is still a macro, so it is even better to rewrite this
>>>> without that:
>>>> function getfn()
>>>> return function(); 1; end
>>>> end
>>>> const n = getfn()
>>>
>>>
>>> This does not give quite the same answer, though, since the function does
>>> not have a name.
>>> Is there a way to specify the name of a generated function like this?
>>>
>>>>
>>>>
>>>> On Sat, May 30, 2015 at 2:30 PM David Gold <david....@gmail.com> wrote:
>>>>>
>>>>> Something to note about Tom's method is that the name function must be
>>>>> passed to gf as a symbol, unlike in the case of a macro. However, in most
>>>>> cases this slight difference probably will not warrant a macro.
>>>>>
>>>>>
>>>>> On Friday, May 29, 2015 at 8:58:56 PM UTC-4, Tom Lee wrote:
>>>>>>
>>>>>> You don't need to use a macro, a function can do this:
>>>>>>
>>>>>> julia> function gf(n::Symbol = gensym())
>>>>>> @eval function $(n)()
>>>>>> 1
>>>>>> end
>>>>>> end
>>>>>>
>>>>>> I've also made the n argument optional, with gensym creating a unique
>>>>>> name by default - the newly defined function is returned by gf, so you
>>>>>> don't
>>>>>> necessarily need to know its name. And of course if you give gf
>>>>>> additional
>>>>>> arguments you can programatically construct expressions based those and
>>>>>> easily $ them into the @eval block. It's all very awesome.
>>>>>>
>>>>>> But the point is a macro probably isn't appropriate for this type of
>>>>>> thing. My understanding is that you should never use a macro if you can
>>>>>> easily write an equivalent function.
>>>>>>
>>>>>> Cheers,
>>>>>>
>>>>>> Tom
>>>>>>
>>>>>> On Thursday, 28 May 2015 23:26:39 UTC+10, Mauro wrote:
>>>>>>>
>>>>>>> Like this:
>>>>>>>
>>>>>>> julia> macro gf(n)
>>>>>>> quote
>>>>>>> function $(esc(n))()
>>>>>>> 1
>>>>>>> end
>>>>>>> end
>>>>>>> end
>>>>>>>
>>>>>>> julia> @gf foo
>>>>>>> foo (generic function with 1 method)
>>>>>>>
>>>>>>> julia> foo()
>>>>>>> 1
>>>>>>>
>>>>>>> On Thu, 2015-05-28 at 12:06, Vasudha Khandelwal
>>>>>>> <vasudhakh...@gmail.com> wrote:
>>>>>>> > Can I use macros to generate functions with names passed as
>>>>>>> > argument to the
>>>>>>> > macro?
>>>>>>>
>>
>
