From: Neil Conway <nconway@...>
Date: 2001-09-09T05:13:34+09:00
Subject: [ruby-talk:21013] length of Ruby array from C?

Hi all,

I've been experimenting with writing some Ruby extensions in C. In order
to find the length of a Ruby array, I needed to do this:

/* -------- */
VALUE ary;
int ary_length;
/* ... assign a Ruby array to "ary" ... */
ary_length = RARRAY(ary)->len;
/* -------- */

There are 2 problems with this, IMHO:

1) undocumented: I had to look through the source to find this

2) clumsy: if this is the only way to get the length, could we perhaps
have some syntactic sugar? For instance, a function (or macro)
rb_ary_length(VALUE), which returns the length of the specified array as
a C integer. Since this is a relatively common operation, I think it
would be worthwhile to make it a bit easier for extension writers.

Otherwise, I've found Ruby's C API very pleasant.

Cheers,

Neil