From: ts <decoux@...>
Date: 2003-12-07T20:56:50+09:00
Subject: Re: creating new Ruby strings in C

>>>>> "C" == Charles Mills <boson@cyberspace.org> writes:

C> Is it possible for RSTRING(str)->ptr to reference a C string or part of a
C> C buffer with out eventually calling free on ptr (and without stopping
C> the gc)?

 yes, and no : see mmap

 mmap can be seen as a delegator : in some case, it just create a String
 object and call the corresponding String method, but it's very carefull
 about the gc

C> What are str_new3 and str_new4 used for?

 shared string used for example in string and regexp. Just an example with
 regexp 

   a = "aaa"
   /.*/ =~ a
   a << "b"


 After the match, $~ and `a' "share" internally the same string, but the
 variable `a' is marked "copy-on-write". When ruby want to modify `a', it
 first duplicate the string and make the modification.


Guy Decoux