From: Nobuyoshi Nakada <nobu@...>
Date: 2010-07-11T18:48:09+09:00
Subject: [ruby-core:31187] Re: [Bug #3558] Passing args with rb_block_call

Hi,

At Sun, 11 Jul 2010 17:44:51 +0900,
Asher Haig wrote in [ruby-core:31186]:
> The short of the problem is that when I call rb_block_call, the called block
> function receives the yield value and data2 appropriately, but argc is
> always set at 1 (no matter what I pass) while argv[ 0 ] and argv[ 2 ] ==
> yield value, and argv[ 1 ] == Qfalse.

You must not access beyond the boundary.

> So far as I can tell from looking at the internals (primarily
> invoke_block_from_c and vm_yield_with_cfunc), no handling is
> being done for the args that were passed to
> rb_block_call. Instead, the specified function gets argc/argv
> from rb_yield, which is always 1 and the value from rb_yield.

Yes.  It's the exactly intended behavior.

> There are only three examples that I see in the Ruby source
> that use rb_block_call while passing args: one in Enumerator,
> and two in Range. The method signatures there provided me
> additional confusion (VALUE i, void* args), as it does not
> match the description of expected functions. Presumably it
> still works since it ends with the void pointer, which is
> being used for variable args.

What do you want to do at all?

-- 
Nobu Nakada