Re: [Vala] embedding c code snippet in vala source.

[Alexey Lubimov <avl l14 ru>]

Ali Sabil пишет:
> On Fri, Aug 22, 2008 at 7:32 AM, Yu Feng <rainwoodman gmail com 
> <mailto:rainwoodman gmail com>> wrote:
>
>
>     On Thu, 2008-08-21 at 23:18 +0100, Emmanuele Bassi wrote:
>     > On Thu, 2008-08-21 at 14:27 -0400, Yu Feng wrote:
>     > > Dear all,
>     > >
>     > > I made a patch that allows embedding c code snippet in vala
>     source.
>     > >
>     > > http://bugzilla.gnome.org/show_bug.cgi?id=548897
>     > >
>     > > This is quite primitive and more has to be done, especially to
>     translate
>     > > the vala variable names to cnames.
>     >
>     > no, please: let's not turn Vala into the new GOB. this makes the
>     code an
>     > unbearable mess - been there, done that.
>     I don't agree with you.
>
>     It is whom that messed up GOB messed up GOB.
>
>     The code snippet is quite different from how embedding c code is
>     done in
>     GOB. Please have a look at the example given in the bug report.
>
>     The embedded code is in unit of member methods. It is something
>     similiar
>     to Watcom's embedding asm in their C compiler. You define a function,
>     and the function has an assembly body.
>
>     People can always write messy code if they like. It doesn't depend on
>     the language features.
>
>     I personally consider the c code embedding more like an
>     alternative way
>     to glue C code with vala than the vast number of quirks in .vapi
>     files.
>
>     The following example may help you appreciate the snoippet patch:
>
>     --------
>     using GLib;
>     /**********VVVVV**/
>     [Compact]
>     class mystring {
>        [CCode (snippet = "gchar ** rt = g_strsplit(this, delimiter,
>     max_tokens); *result_length1 = rt?g_strv_length(rt):0; return rt;")]
>        public string[] mysplit (string delimiter, int max_tokens = 0);
>     }
>     /***^^^^^^^^^^^^^*/
>     class ClassA: Object {
>        public static void main(string [] args) {
>            ClassA obj = new ClassA();
>            string test = "hello world\n line 2\n line3\n";
>            string [] lines = ((mystring)test).mysplit("\n", -1);
>            foreach(string s in lines) {
>                message("%s", s);
>            }
>        }
>     }
>     -------
>
>     mystring.mysplit is an analogue with GLib.string.split, but it returns
>     the string length as well.
>
>     I am working on a further patch to compile the wrapped (with VVV ^^^)
>     code even if it is in a .vapi file.
>
>     At least this snippet thing can help us move some of knowledge of GLib
>     away from valac to the .vapi bindings. (hopefully also the reference
>     counting hell of GList, GSlist, and even vala array).
>
>     There is also a hope to solve
>     http://bugzilla.gnome.org/show_bug.cgi?id=548897 as mentioned by
>     Alexey.
>
>     Cheers,
>
>
> Did you know that vala supports the "extern" modifier ?
>
> extern void foo (int f);
>
> and then create a .c file and define
> void foo (int f) {g_debug ("Hello world %d", f);}
>
> and then compile and link everything.
Only yesterday, I,m first time use function split from GLib.string

strings[] test= "1 2 3".split(" ")
stderr.printf("%ld",test.length);

*no error, no warning*, but test.length always == -1.



I'm read glib manual, when view glib-2.0.vapi and write this code

     string fio = e_fio.get_text();
     fio=fio.strip();
     uint length=0;
     string[] strings;
    
     if ((fio != null) && (fio !=""))
     {
       strings = fio.split(" ");
       length =  GLib.strv_length(strings);
     }

I think, this is mess.

This code work fine, but I hope, in future, vala (bindings) will be more 
friendly to me and this code will be obsolete by simple

strings = fio.split(" ");



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