Re: Java Versus gtk

[Michael L Torrie <torriem chem byu edu>]

On Wed, 2004-02-18 at 04:06, Karoliina Salminen wrote:
> I don't mean that. I mean that there are built-in classes for many
> kind of things in C++ standard library. One example is STL.
> For example we needed a linked list to the program. It was easy to 
> implement with C and there are millions of examples how to do it,
> but it was about 1000 lines of extra code where it would have been
> in C++ just one line: std::list<std::string> stringlist;

I personally think that the glib part of gtk gives you almost all the
functionality to do what you've demonstrated using STL.  In some
respects glib is a standard template library.

> > I haven't seen such
> > dramatic examples.
>
> One example: A simple dictionary where keyword (string) points
> to a list of strings:
> Try this with C (how many hundreds of lines of code you'll get since
> in C you must implement a tree to accomplish the same efficiency
> and in the std::map which used internally a red-black tree):

glib gives stack and vector capability, as well as trees (various
kinds).  I've used glib extensively in a non-gtk application and the
glib routines gave me almost as much power of as STL, all with standard
C.  STL is nice, but sometimes buggy and not always supported by C++
compilers.

> #include <string>
> #include <vector>
> #include <map>
> ...
>
> std::map<std::string,std::vector<std::string> > stringmap;
>
> std::vector<std::string> translation;
> translation.push_back(std::string("tietokone"));
> translation.push_back(std::string("tietojenkäsittelylaite"));
> stringmap[std::string("computer")]=translation;
> std::vector<std::string> diggedFromMap = 
> stringmap[std::string("computer")];
> std::cout << diggedFromMap[0] << std::endl;
> std::cout << diggedFromMap[1] << std::endl;

Maybe I'm not understanding your code, but here goes:

#include <glib.h>

GHashTable *stringmap = g_hash_table_new(g_str_hash,g_str_equal);
GSList *translation = NULL;
GSList *diggedFromMap = NULL;

translation=g_slist_append(translation,"tietokone");
translation=g_slist_append(translation,"tietojenkäsittelylaite");
g_hash_table_insert(stringmap,"computer",translation);
diggedFromMap=g_hash_table_lookup(stringmap,"computer");
g_print("%s\n",diggedFromMap->data);
g_print("%s\n",diggedFromMap->next->data);



Clearly that code is not as robust nor safe (or probably even correct)
but I just wanted to show that C can be almost a flexible as C++.  Also
STL isn't part of C++, but rather a library, just like glib.  If you
pick your library correctly (as in use gtk and glib) I think you can do
just as much as C++, but often in a more portable way.

Michael



> (Sorry, I didn't verify if there are typos in my code, it is possible
> that it won't work).
>
> > Also regard that most accesses to C++ objects are
> > done technically via pointers as well. Just the notation differs.
>
> Of course there are pointers, but for example dynamic memory allocation
> can be left to the problem of the standard library and the user
> can write code that never leaks assuming that the standard library
> contains no bugs. In STL it is implemented better than in Java.
> The garbage collection rarely works right and Java programs tend to leak.
> In STL however, memory is freed when a structure goes out of visibility
> (past end of the block).


> Best Regards,
> Karoliina Salminen
>
> /*  
>  * | Karoliina Salminen | karoliinasalminen karoliinasalminen com |
>  * | http://www.karoliinasalminen.com | http://www.ampcast.com/karoliina |
>  *
>  */
>
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-- 
Michael L Torrie <torriem chem byu edu>