digitalmars.D.learn - compile time printf -> .NET style format string conversion template.
- Neal Alexander (29/29) Jan 03 2008 Alright the basic idea behind this was:
- Neal Alexander (7/45) Jan 03 2008 figured out one of the questions at least haha:
- Matti Niemenmaa (11/11) Jan 04 2008 Neal Alexander wrote:
Alright the basic idea behind this was:
- During tango porting i want all the stdlib wrapping done in 1 module.
- Any function that takes a format string cant be wrapped transparently
without converting the string or doing something half baked (right?).
So i wrote this compile-time conversion template:
http://paste.dprogramming.com/dpjq2ug6 (See the FMT template for
discussion purposes. The rest is just conversion/parsing).
Now for the questions:
- Why cant i do return x ~ FMT!(s[i .. $]); at line 106? This would
avoid having to call skip() to count the fmt string length a 2nd time.
The compiler complains s[i .. $] is an invalid argument or somethig.
- How do i template the print function so that the compiler retains the
immediateness of the format string arg.
with something like this you'd have to do:
---------------------------
void print(T...)(T t)
{
version (Tango) Stdout.formatln(t);
else writefln(t);
}
print(FMT!("whatever %d"), 0);
where ideally you would want something like this:
---------------------------
void print(T...)(char[] fmt, T t)
{
version (Tango) Stdout.formatln(FMT!(fmt), t);
else writefln(fmt, t);
}
print("whatever %d", 0);
Jan 03 2008
Neal Alexander wrote:
Alright the basic idea behind this was:
- During tango porting i want all the stdlib wrapping done in 1 module.
- Any function that takes a format string cant be wrapped transparently
without converting the string or doing something half baked (right?).
So i wrote this compile-time conversion template:
http://paste.dprogramming.com/dpjq2ug6 (See the FMT template for
discussion purposes. The rest is just conversion/parsing).
Now for the questions:
- Why cant i do return x ~ FMT!(s[i .. $]); at line 106? This would
avoid having to call skip() to count the fmt string length a 2nd time.
The compiler complains s[i .. $] is an invalid argument or somethig.
- How do i template the print function so that the compiler retains the
immediateness of the format string arg.
with something like this you'd have to do:
---------------------------
void print(T...)(T t)
{
version (Tango) Stdout.formatln(t);
else writefln(t);
}
print(FMT!("whatever %d"), 0);
where ideally you would want something like this:
---------------------------
void print(T...)(char[] fmt, T t)
{
version (Tango) Stdout.formatln(FMT!(fmt), t);
else writefln(fmt, t);
}
print("whatever %d", 0);
figured out one of the questions at least haha:
template print(char[] fmt, T...)
{
void print(){ Stdout.formatln(FMT!(fmt), T); }
}
print!(...);
Jan 03 2008
Neal Alexander wrote: In case you're interested, attached is my (command-line tool) attempt at doing the same thing: converting writef's formatting strings to Tango's. I soon gave up as doing a character-by-character exact conversion leads to too many special cases. It's a couple months old and thus probably doesn't even compile with the current Tango. On top of that, the code is fairly ugly as I didn't expect it to blow up to such a length. But if you want to support everything writef parses (what I tried) there might be something of use in there. -- E-mail address: matti.niemenmaa+news, domain is iki (DOT) fi
Jan 04 2008









Neal Alexander <wqeqweuqy hotmail.com> 