It's possible to have a macro in Julia that emulates Python decorators. But
it's a separate question whether you really want to do it, there might be
more efficient/elegant ways to achieve the same in Julia for a specific use
case.
Here's a macro that emulates Python decorators and an example how to use it:
julia> macro decorator(dec, func)
name = func.args[1].args[1]
hiddenname = gensym()
func.args[1].args[1] = hiddenname
quote
$func
const $(esc(name)) = $dec($hiddenname)
end
end
julia> foo(f) = x->2*f(x+10)
julia> @decorator foo function bar(x)
return x+1
end
julia> bar(0)
22
This is the same as in Python
In [2]: def foo(f):
...: return lambda x: 2*f(x+10)
...:
In [3]: @foo
...: def bar(x):
...: return x+1
...:
In [4]: bar(0)
Out[4]: 22
Of course, one can also use this for something useful :-), like:
julia> logger(f) = x-> (println("input: $x"); result = f(x); println("output:
$result"); result)
logger (generic function with 1 method)
julia> @decorator logger baz(x)=x+1
(anonymous function)
julia> baz(3)
input: 3
output: 4
4
On Monday, May 9, 2016 at 3:42:22 PM UTC+2, Ford Ox wrote:
>
> Is it possible to write macro that will work as python decorator?
