Currently I have this template:

template seqWrapper (char[] property, alias seq, alias array)
{
	const seqWrapper = typeof(array).stringof ~ " " ~ property ~ "()"
	"{"
	"if (" ~ array.stringof ~ ".length == 0)"
	"	" ~ array.stringof ~ " = seqToArray (" ~ seq.stringof ~ ");"
	"return " ~ array.stringof ~ ";"
	"}";
}

Which is simply used like this:

mixin (seqWrapper!("users", _list, _users));

And it works. But I was wondering if it was better to have it as a compile-time function, and if so, how it could be changed. I'm using D1.0, btw.

-- 
Carlos Santander Bernal

Carlos Santander wrote:
> Currently I have this template:
> 
> template seqWrapper (char[] property, alias seq, alias array)
> {
>     const seqWrapper = typeof(array).stringof ~ " " ~ property ~ "()"
>     "{"
>     "if (" ~ array.stringof ~ ".length == 0)"
>     "    " ~ array.stringof ~ " = seqToArray (" ~ seq.stringof ~ ");"
>     "return " ~ array.stringof ~ ";"
>     "}";
> }
> 
> Which is simply used like this:
> 
> mixin (seqWrapper!("users", _list, _users));
> 
> And it works. But I was wondering if it was better to have it as a compile-time function, and if so, how it could be changed. I'm using D1.0, btw.
> 

string seqWrapper(string property, string seq, string array)
{
    return `typeof(`~array~`) `~property~`()
    {
        if( (`~array~`).length == 0 )
            `~array~` = seqToArray(`~seq~`);
        return `~array~`;
    }`;
}

mixin (seqWrapper("users","_list","_users"));

Six of one, half-dozen of the other, really.  Unless you need to do
stuff involving loops or string processing, templates are quite sufficient.

	-- Daniel

Daniel Keep escribió:
> 
> string seqWrapper(string property, string seq, string array)
> {
>     return `typeof(`~array~`) `~property~`()
>     {
>         if( (`~array~`).length == 0 )
>             `~array~` = seqToArray(`~seq~`);
>         return `~array~`;
>     }`;
> }
> 
> mixin (seqWrapper("users","_list","_users"));
> 

I hadn't thought of that first line with typeof. Thanks.

> Six of one, half-dozen of the other, really.  Unless you need to do
> stuff involving loops or string processing, templates are quite sufficient.
> 
> 	-- Daniel

I was thinking about code-generation bloat, but I guess I'd have to measure that myself.

-- 
Carlos Santander Bernal

Carlos Santander wrote:

> I was thinking about code-generation bloat, but I guess I'd have to measure that myself.

If you only use the wrapper function in CTFE, try moving it to a separate module and not linking it, just importing. That way no unnecessary code is generated to the final executable or object files.

Jari-Matti Mäkelä escribió:
> Carlos Santander wrote:
> 
>> I was thinking about code-generation bloat, but I guess I'd have to
>> measure that myself.
> 
> If you only use the wrapper function in CTFE, try moving it to a separate
> module and not linking it, just importing. That way no unnecessary code is
> generated to the final executable or object files.

Nice tip. Thanks.

-- 
Carlos Santander Bernal