On 26.11.2015 09:33, Louie F wrote:
I found out that compile time optimization is quite useful specially for
database queries, instead of it being generated at every call, it can be
generated like I typed it using compile time optimizations... so I thought,
Is it possible to convert an array of values or a list from a file to
variables or struct at compile time?
So basically I have a database, instead of writing a struct, I would
like to query the database for the list of tables and their column
information then parse that as a struct or variables for parsing so that
I could use it, so that if I delete or add columns I then only need to
recompile the code and not worry about editing files...
class Users
{
/*
query the database and create fields at compile time and
use the variables below
*/
void create(){
this.name = "Louie";
}
}
or something like this...
foreach(table_names, key; table){
/*
generate struct using table and informations
*/
}
you can do something like:
auto createColumnDescription(Description...)()
{
string s;
foreach(description; Description){
s ~= description[0] ~ " " ~ description[1] ~ ";\n");
return s;
}
struct Table(ColumnDescription)
{
// pragma(msg, createColumn!ColumnDescription); // uncomment this
to see what will be mixed
mixin(createColumn!ColumnDescription);
}
the table contains a range of tuples of column type and name and should
be available at compile-time
But it isn't tested and I'm not sure it's the best way.
