Re: main function signature?

Rajesh Walkay wrote:
> If pointers are second class citizens in C2, what would be the main 
> function signature? 

It depends on what type is str of in the following expression:

T str = "What am I";

Knowing the answer to the above will help us determine the signature of 
the main function.

In C++, T is of type:
const char*           <- pointer to const characters

In C2, T might be of type:
[]<char const> local^ <- reference to local array of
                          const characters

Since argv in C++ is a pointer to pointers to const chars, C2 argv would 
be declared as a reference to array of references to arrays of const 
characters. Our main function would then have a signature:

int Main(int, []<[]<char const> any^> any^);

I can just imagine your disappointment-- it surely looks easy to make a 
mistake.

The easiest way to make it shorter would be to declare a typedef in some 
standard header:

// file: System.h2
namespace System
{
   typedef int RtCode;
   typedef int Argc;
   typedef []<[]<char const> any^> any^ Argv;
   typedef []<[]<char const> any^> any^ Env;
   // ...
}

We would then write:

// file: UserMain.c2
#include <System.h2>

using namespace System;

RtCode Main(Argc, Argv)
{
}

Using plain arrays is not a convenient method of dealing with sequences 
of characters. Arrays do not resize nor support encoding schemes (UTF, 
ASCII...) to name a few deficiencies. Instead, String class should be 
used by passing an array of const characters to its constructor:

template <typename Ty, typename Enc, ...>
class String
{
public:
   String([]<Ty const> any^ str);
   // ...
};

// and somewhere else we might have:
typedef String<char, AsciiEncoding<char>, ...> AsciiString;
typedef String<char, UtfEncoding<char>, ...>   Utf8String;
typedef String<short, UtfEncoding<short>, ...> Utf16String;
typedef String<int, UtfEncoding<int>, ...>     Utf32String;
// ...

We could then write something like:

using namespace System;

RtCode Main(Argc argc, Argv argv)
{
   AsciiString programName = argv[0];
   // ...
   return skSuccessCode;
}

--

-- 
Slawomir Lisznianski
C2 Language Group Principal (http://c2-lang.org)

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