Code.ensure_loaded? will load the module if one os available. However I would strongly suggest to stop guessing and keep atoms and modules apart, maybe by passing a tuple. Otherwise, what if you want to pass an atom and it happens to have the same name as an Erlang module?
On Thursday, July 21, 2016, OvermindDL1 <overmind...@gmail.com> wrote: > Confirmed it is what I thought it was: > ```elixir > iex(16)> :erlang.function_exported(:observer, :module_info, 0) > false > iex(17)> :observer.start > :ok > iex(18)> :erlang.function_exported(:observer, :module_info, 0) > true > ``` > > On Thursday, July 21, 2016 at 12:41:18 PM UTC-6, OvermindDL1 wrote: >> >> Oh, and I might know why, the module might not be loaded yet. Until code >> is actually called in the module then it is not loaded into the VM, but >> once loaded it stays loaded, I actually have something that manages that in >> my Plugin system that handles dynamic Module detection and loading: >> ```elixir >> iex(14)> ExPlugins.get_plugins(MyServer.PermsBehaviour) >> [MyServer.Perms.Auth.Permission, MyServer.Perms.Auth.Profile, >> MyServer.Perms.Auth.Users, MyServer.Perms.Auth, >> MyServer.Perms.Help.Issue, >> MyServer.Perms.Help, MyServer.Perms.Messenger, >> MyServer.Perms.SomeOtherSection.Report, >> MyServer.Perms.SomeOtherSection.Requirement, >> MyServer.Perms.SomeOtherSection.Semester, >> MyServer.Perms.SomeOtherSection.Student.Requirement, >> MyServer.Perms.SomeOtherSection.Student.Semester, >> MyServer.Perms.SomeOtherSection.Student, >> MyServer.Perms.SomeOtherSection, MyServer.Perms.Tag] >> ``` >> It is my Elixir port of my old Erlang plugin system (so much easier to >> write here). It detects what module implement a behaviour, verify they are >> loaded into the system, if not it loads them, then returns a list of them >> (while caching the results for faster response later along with being able >> to purge the cache via `ExPlugin.clear_cache(MyServer.PermsBehaviour)` or >> just `ExPlugin.clear_cache()` to clear everything. But yes, I had to load >> the modules properly to detect their information. >> >> On Thursday, July 21, 2016 at 12:32:43 PM UTC-6, OvermindDL1 wrote: >>> >>> Nope, something is borked for you: >>> ```elixir >>> iex(12)> :erlang.function_exported(GenEvent.Stream, :module_info, 0) >>> true >>> ``` >>> >>> On Thursday, July 21, 2016 at 12:28:28 PM UTC-6, Theron Boerner wrote: >>>> >>>> True, OvermindDL1's is the way to go unless you need info about the >>>> module. Anyone know why this doesn't work?: >>>> >>>> iex(11)> :erlang.function_exported(GenEvent.Stream, :module_info, 0) >>>> false >>>> >>>> or >>>> >>>> iex(1)> :erlang.get_module_info(GenEvent.Stream, :module) >>>> ** (ArgumentError) argument error >>>> :erlang.get_module_info(GenEvent.Stream, :module) >>>> >>>> Could it be because it defined a struct? >>>> >>>> On Thu, Jul 21, 2016 at 1:20 PM OvermindDL1 <overm...@gmail.com> wrote: >>>> >>>>> That requires dealing with an error and having a try/catch and it is >>>>> just a pain. As I mentioned before, testing if the function >>>>> `module_info/0` exists I think is a great way: >>>>> ```elixir >>>>> iex(9)> :erlang.function_exported(:blah, :module_info, 0) >>>>> false >>>>> iex(10)> :erlang.function_exported(String, :module_info, 0) >>>>> true >>>>> ``` >>>>> >>>>> >>>>> On Thursday, July 21, 2016 at 12:14:30 PM UTC-6, Theron Boerner wrote: >>>>>> >>>>>> Use this: >>>>>> >>>>>> iex(7)> :erlang.get_module_info(String, :module) >>>>>> String >>>>>> iex(8)> :erlang.get_module_info(:lists, :module) >>>>>> :lists >>>>>> iex(9)> :erlang.get_module_info(:walrus, :module) >>>>>> ** (ArgumentError) argument error >>>>>> :erlang.get_module_info(:walrus, :module) >>>>>> >>>>>> >>>>>> >>>>>> On Thursday, July 21, 2016 at 12:20:46 PM UTC-5, ...Paul wrote: >>>>>>> >>>>>>> Not saying this is a great idea, but I'm working with a pattern >>>>>>> where a parameter can be a module or a string. The gist is: >>>>>>> >>>>>>> def do_it(data, foo) when is_bitstring(foo), do: data >>>>>>> def do_it(data, foo) do >>>>>>> foo.do_other_thing(data) >>>>>>> end >>>>>>> >>>>>>> Works great, but what if I want to allow actual atoms to be used, >>>>>>> similar to strings? How can I identify the difference between an actual >>>>>>> atom, like :bar, and a module, like Bar? >>>>>>> >>>>>>> is_atom() returns true for both cases (makes sense because module >>>>>>> names are basically atoms, :"Elixir.Bar") Is there a way to tell the >>>>>>> difference with a guard? >>>>>>> >>>>>>> If not a guard, some Kernel or Module function? >>>>>>> >>>>>>> ...Paul >>>>>>> >>>>>>> >>>>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "elixir-lang-talk" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to elixir-lang-ta...@googlegroups.com. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/elixir-lang-talk/9fed8269-f58f-4d65-b369-ea6477b2126a%40googlegroups.com >>>>> <https://groups.google.com/d/msgid/elixir-lang-talk/9fed8269-f58f-4d65-b369-ea6477b2126a%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> -- > You received this message because you are subscribed to the Google Groups > "elixir-lang-talk" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to elixir-lang-talk+unsubscr...@googlegroups.com > <javascript:_e(%7B%7D,'cvml','elixir-lang-talk%2bunsubscr...@googlegroups.com');> > . > To view this discussion on the web visit > https://groups.google.com/d/msgid/elixir-lang-talk/ea35fb1e-a2b6-4029-9425-ea71d265ee24%40googlegroups.com > <https://groups.google.com/d/msgid/elixir-lang-talk/ea35fb1e-a2b6-4029-9425-ea71d265ee24%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- *José Valim* www.plataformatec.com.br Skype: jv.ptec Founder and Director of R&D -- You received this message because you are subscribed to the Google Groups "elixir-lang-talk" group. 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