I don't know why my previous version won't work,BUT
```
macro nb(f, args...)
:($f($(arg...)))
end
```
will get the right result. What's the difference between `quote .. end` and
`:( .. )` then?
:P
On Thu, Jan 15, 2015 at 11:06 AM, Isaiah Norton <isaiah.nor...@gmail.com>
wrote:
> julia> macro nb(f, args...)
> arg1 = map(x->:($(esc(x))), args)
> :($f($(arg1...)))
> end
>
> julia> @nb print arr
> [0.0,0.020100000000000007, ...
>
> If you haven't used it already, I would suggest to look at macroexpand to
> see the expression resulting from each macro (for example, look at why the
> previous version didn't work).
>
> julia> macroexpand( :(@nb print arr) )
>
> On Wed, Jan 14, 2015 at 8:32 PM, yi lu <zhiwudazhanjiang...@gmail.com>
> wrote:
>
>> Well, I don't get it very clearly. I learnt that 'esc' changes variable
>> names of a local variable in the macro. But I want to reference the global
>> variable out of the macro. I have little idea of Lisp macros, so I think I
>> still cannot handle this.
>> Would you please add more details?
>>
>> Yi
>>
>> On Wed, Jan 14, 2015 at 11:37 PM, Isaiah Norton <isaiah.nor...@gmail.com>
>> wrote:
>>
>>> You need to use 'esc' -- see the hygiene part of the metaprog section in
>>> the manual.
>>> On Jan 14, 2015 8:56 AM, "yi lu" <zhiwudazhanjiang...@gmail.com> wrote:
>>>
>>>> Hi,
>>>>
>>>> I am able to write a simple macro to drop brackets.
>>>> https://gist.github.com/eccstartup/36637d96355bd5ca8188
>>>>
>>>> But there is some problem with this.
>>>>
>>>> You can see the @nobrace macro that drop brackets of functions.
>>>> For example:
>>>> ```
>>>> @nobrace map (x->x^2-1) 1:0.01:2
>>>> ```
>>>> get a list of Float numbers. This is fine.
>>>>
>>>> However, in the macro, we cannot see global variables.
>>>> For example:
>>>> ```
>>>> arr = @nobrace map (x->x^2-1) 1:0.01:2
>>>> print(arr)
>>>> ```
>>>> will print the "arr" list, but
>>>> ```
>>>> arr = @nobrace map (x->x^2-1) 1:0.01:2
>>>> @nobrace print arr
>>>> ```
>>>> will report "arr not found".
>>>>
>>>> Is there a remedy?
>>>>
>>>>
>>>> Yours,
>>>> Yi
>>>>
>>>
>>
>
