silverhammermba/emberb

A guide to Ruby's C API

emberb's Issues

Document hash functions

There are many functions that work directly on Hashes like rb_hash_aref().

I can write a PR if you can tell me where the text is to go.

Document interfacing with complex numbers

There almost zero documentation on complex numbers even in the README.EXT file in the Ruby sources (except the name of the file in which complex numbers are present).

Documenting this would be very very helpful.

How to handle malloc error?

What happened when the malloc return NULL (no memory)

/* GMP::Integer.allocate */
VALUE integer_c_alloc(VALUE self)
{
	mpz_t* data = malloc(sizeof(mpz_t));
	/* GMP initialization */
	mpz_init(*data);

	return Data_Wrap_Struct(self, NULL, integer_free, data);
}

Typos and small errors

"for too many", "if it’s method of automatically"

"load in Ruby" links to a specific doc version

Use an actual trendy smiley emoji in the example so the kids will like you

Document all basic types operations in table form

It would be helpful to have a table with a one-to-one correspondence between the Ruby operation and the equivalent C API call.

For example:

Array

Ruby	C	Description
#[]	rb_ary_entry()	specify things about args etc.

Problem while running Ruby code from C

After a clean compilation I get the following error when I try to run the compiled binary on OS X El Capitan.

dyld: lazy symbol binding failed: Symbol not found: _ruby_init
  Referenced from: /Users/user/p/c/playground/./a.out
  Expected in: flat namespace

dyld: Symbol not found: _ruby_init
  Referenced from: /Users/user/p/c/playground/./a.out
  Expected in: flat namespace

[1]    64228 trace trap  ./a.out

The compilation flags are as follows:

$ gcc call_ruby.c $(pkg-config --cflags --libs ruby-2.2)

And pkg-config evaluates to the following:

-I/Users/user/.rbenv/versions/2.2.2/include/ruby-2.2.0/x86_64-darwin15 -I/Users/user/.rbenv/versions/2.2.2/include/ruby-2.2.0 -Wl,-undefined,dynamic_lookup -Wl,-multiply_defined,suppress -lpthread -lgmp -ldl -lobjc

I tried to recompile Ruby as I upgraded OS version in the meantime, but didn't change anything.

How should I do the translation

These are awesome posts. Thanks a lot. I wanna translate them to Chinese. Should I fork this and do the translation? Or is Jekyll support the translation stuff?

Missing link for "when" in The Ruby C API

Hello,

I noticed that there is no URL for the [when] reference on "The Ruby C API".
I looked in the Git history, and it seems that the link was missing from the beginning. Here is the first commit that adds this footnote:

emberb/_posts/2010-01-01-c.markdown

Lines 294 to 297 in 7b05175

	[^5]: The documentation [states](../reamde#control-structure) that "You have to
	clear the error info [when] ignoring the caught exception". But I'm not
	aware of any case where it would be cleared for you – it seems like
	you _always_ have to clear it.

Thank you.

"gaping whole" should be "gaping hole"

LICENSE file

It seems obvious from the running website that you wish all this to be under: Creative Commons Attribution 4.0 International License.

However, it would be a good idea IMHO to have the license in a LICENSE file in the root of the repository so that people (like me) who were trying to make a pull request and wanted to know what license it was under have a more accessible place for this information.

rb_cData is deprecated

Hi,

The guide recommends inheriting from rb_cData, but it's been deprecated and will be removed. Instead we should inherit from rb_cObject.

Explain how to build an extension with CMake

What the title says.

Add allocation section

Mention the ALLOC/ZALLOC/REALLOC macros, what they're used for, why they are important.

`ruby_options` no longer optional in 3.2?

According to this SO question, just calling ruby_init no longer works in Ruby 3.2 and you have to call ruby_options prior to setting the load path.

Figure out why that is and update the instructions for running Ruby in C.

Data_Wrap_Struct is deprecated

See official docs.

Need to update the section on wrapping C data.

How writing dup()

I create c extension. How creating a duplicate my object?
How running function of object inside c?

Document string encoding functions

Creation of strings with certain encoding is documented in README.EXT but there's nothing on dealing with encoding.

Having a section dedicated to that would be good.