My use case is that I'm writing a large number of functions, all displaying messages containing the function name (think informative error messages). Accessing the function name would slightly simplify the code.
The Python PEP was rejected but it's still possible in Python (e.g., using the introspect module). It's even possible in Matlab (using dbstack)! (I'm not saying it's entirely safe.) On Wednesday, August 5, 2015 at 3:56:12 PM UTC-4, Yichao Yu wrote: > > On Wed, Aug 5, 2015 at 2:42 PM, Cedric St-Jean <[email protected] > <javascript:>> wrote: > > In my case, I wanted to count how many times some functions were called. > > Kinda like a profiler, but for a different purpose. If the function name > was > > available, I could move the macro "call" inside the function body, which > > would make more sense. > > Than what about sth like > > ```julia > macro count_execute() > @gensym counter > quote > global $counter > if isdefined(:($counter)) > $counter = $counter::Int + 1 > else > $counter = 0 > end > end > end > ``` > > > > > On Wednesday, August 5, 2015 at 2:25:42 PM UTC-4, Isaiah wrote: > >> > >> I'm still curious what problem / design this is trying to solve. Be > aware > >> that doing something like this for custom runtime dispatching is likely > to > >> be slow (except in the macro case which does not really count). > >> > >> Are you both coming from some other programming language that exposes > this > >> in a first-class way? Both PHP and JavaScript seem to make this > information > >> available, but R does not (except for a callstack hack). > >> > >> On Wed, Aug 5, 2015 at 2:10 PM, Cedric St-Jean <[email protected]> > >> wrote: > >>> > >>> I also wish that the name was visible... I wrote the macro a few days > >>> ago: > >>> > >>> macro expose_name(fdef) > >>> @capture(fdef, begin function fname_ (args__) body__ end end) > >>> esc(:(function $(fname) ($(args...)) > >>> let function_name = $(Expr(:quote, fname)) > >>> $(body...) > >>> end)) > >>> end > >>> > >>> @expose_name function foo () @show function_name end > >>> > >>> Cédric > >>> > >>> > >>> > >>> On Wednesday, August 5, 2015 at 12:54:38 PM UTC-4, Tim Holy wrote: > >>>> > >>>> Alternatively, > >>>> > >>>> julia> for (offset, f) in enumerate((:foo1, :foo2, :foo3)) > >>>> @eval begin > >>>> function $f(x) > >>>> println("This is ", $f) > >>>> x + $offset > >>>> end > >>>> end > >>>> end > >>>> > >>>> julia> foo1(0) > >>>> This is foo1 > >>>> 1 > >>>> > >>>> julia> foo2(0) > >>>> This is foo2 > >>>> 2 > >>>> > >>>> julia> foo3(0) > >>>> This is foo3 > >>>> 3 > >>>> > >>>> --Tim > >>>> > >>>> On Wednesday, August 05, 2015 12:48:29 PM Isaiah Norton wrote: > >>>> > Can I ask what is your use-case, and whether you've done this in > some > >>>> > other > >>>> > language? From a quick google there are appear to be some (possibly > >>>> > non-standard) C and C++ compiler defines that provide the current > >>>> > function > >>>> > name, but other than that: > >>>> > > >>>> > - Python rejected a PEP for this feature ( > >>>> > https://www.python.org/dev/peps/pep-3130/) > >>>> > - Java does not support it in a first-class way ("could use > >>>> > stacktrace, but > >>>> > potentially unreliable") > >>>> > - some lisps appear to have interactive mode support for this kind > of > >>>> > introspection, but nothing general. > >>>> > > >>>> > The recommended way to solve problems that require this level of > >>>> > introspection is to do code generation via metaprogramming. > >>>> > > >>>> > > >>>> > On Wed, Aug 5, 2015 at 12:36 PM, Isaiah Norton <[email protected]> > > >>>> > > >>>> > wrote: > >>>> > > No. > >>>> > > > >>>> > > Ok, technically, you could do this (inspired by > >>>> > > > >>>> > > > https://github.com/JuliaLang/julia/issues/8066#issuecomment-61136584): > >>>> > > > >>>> > > julia> function foo() > >>>> > > > >>>> > > bt = backtrace() > >>>> > > lookup = ccall(:jl_lookup_code_address, Any, (Ptr{Void}, > >>>> > > Int32), > >>>> > > > >>>> > > bt[2], 0) > >>>> > > > >>>> > > name = lookup[1] > >>>> > > end > >>>> > > > >>>> > > foo (generic function with 1 method) > >>>> > > > >>>> > > julia> foo() > >>>> > > > >>>> > > :foo > >>>> > > > >>>> > > But that is a really, really bad idea. Please don't do that. > >>>> > > > >>>> > > On Wed, Aug 5, 2015 at 12:04 PM, Dominique Orban < > >>>> > > > >>>> > > [email protected]> wrote: > >>>> > >> Sorry if this has been asked before. Is it possible to determine > >>>> > >> the name > >>>> > >> of a function inside that function? For example, > >>>> > >> > >>>> > >> function blah(x) > >>>> > >> > >>>> > >> my_name = ... # should evaluate to "blah" or :blah > >>>> > >> > >>>> > >> end > >>>> > >> > >>>> > >> I didn't see that in the introspection section of the > >>>> > >> documentation. > >>>> > >> > >>>> > >> Thanks! > >>>> > >> > > >
