[erlang-questions] [Erlang]about "apply" function in the erlang.erl

[Richard O'Keefe]

On 17/05/2011, at 7:48 PM, 郎咸武 wrote:

> hi,
>    I see "apply" function invoke "apply“function in the  "erlang.erl".
>    I can`t understand it. 
>    Who can explain for me? Thanks.
> 
>  57 apply(Fun, Args) ->
>  58     apply(Fun, Args).
>  59 
>  60 apply(Mod, Name, Args) ->
>  61     apply(Mod, Name, Args).

It's a fairly common "bootstrapping" sort of thing.
Presumably
 - when the compiler sees apply/2 or apply/3 in an expression
   it generates special in-line code
 - there needs to be a "real" function definition so that it
   can be called indirectly itself, discoverable in the
   module exports, traced if calls arrive that way in the
   debugger, &c