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November 16, 2010
Another SQLite3 wrapper
Hello!

I tried to find any module to work with SQLite3 in D2, and failed. I
found either just bindings to old SQLite versions or D1 modules with
"craft-SQL-on-the-fly" interface, all abandoned.
So I want to add just another D2 SQLite3 bindings and OO-wrapper and
uploaded to GitHub: https://github.com/bayun/SQLite3-D
It seems that no-one wants to support bindings for current SQLite
version.. Well, I'll try to do this. But I currently use very small
subset of it's features, so it's mostly mechanical translation without
further testing.
My tiny OO interface supports prepare/bind style of statements, and
seems to work good :-) But I'm new to D, and will be grateful to
somebody who can check, if my code is correct and don't have subtle
bugs.
Also I cannot figure if this code can be writen simpler:

void getRow(T...)(ref T args) {
	foreach(i, arg; args) {
		args[i] = mixin("getValue!" ~ typeof(arg).stringof ~ "(i)");
	}

}

I want there to call appropriate overloaded function for each item of
args tuple, but I was not able to do this without mixin - compiler
gives syntax errors when I try to write something like "args[i] =
getValue!T[i](i);"

Also if I try to assign to arg, and not args[i], changes are not
propagated to variables given as function arguments, even if I have
foreach(ref... syntax. Is it a bug or I just don't understand
something?

--
WBR,
Alexey Khmara
November 16, 2010
Re: Another SQLite3 wrapper
While it might be better to update existing projects, here are some answers.

Alexey Khmara Wrote:

> I want there to call appropriate overloaded function for each item of
> args tuple, but I was not able to do this without mixin - compiler
> gives syntax errors when I try to write something like "args[i] =
> getValue!T[i](i);"

Try using: getValue!(T[i])(i), the !() shortcut doesn't work with arrays. Might be a bug, but I don't think it necessarily should.

> Also if I try to assign to arg, and not args[i], changes are not
> propagated to variables given as function arguments, even if I have
> foreach(ref... syntax. Is it a bug or I just don't understand
> something?

Not sure what your ref syntax looks like, but it should be like below.

foreach(i, ref arg; args) {
November 16, 2010
Re: Another SQLite3 wrapper
2010/11/16 Jesse Phillips <jessekphillips+D@gmail.com>:
> While it might be better to update existing projects, here are some answers.
>
> Alexey Khmara Wrote:
>
>> I want there to call appropriate overloaded function for each item of
>> args tuple, but I was not able to do this without mixin - compiler
>> gives syntax errors when I try to write something like "args[i] =
>> getValue!T[i](i);"
>
> Try using: getValue!(T[i])(i), the !() shortcut doesn't work with arrays. Might be a bug, but I don't think it necessarily should.
>
>> Also if I try to assign to arg, and not args[i], changes are not
>> propagated to variables given as function arguments, even if I have
>> foreach(ref... syntax. Is it a bug or I just don't understand
>> something?
>
> Not sure what your ref syntax looks like, but it should be like below.
>
> foreach(i, ref arg; args) {
>

I tried to use this:
foreach(ref i, arg; args) {

I was stupid - don't realized that ref affects only one argument, not
all of them :-)

Thanks, for suggestions, all works good now :-)
But strangely, assign not to arg, but to args works also, this line:

args = getValue!(T[i])(i);

gets compiled and gives correct results... Not a bad, but I cannot
understand why - seems like assigning one value to tuple...

-- 
WBR,
Alexey Khmara
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