Better Debugging With Metaprogramming

[Kyle Siefring via Digitalmars-d]

On Friday, 12 September 2014 at 01:19:40 UTC, Kyle Siefring wrote:
> On Friday, 12 September 2014 at 01:17:10 UTC, Kyle Siefring 
> wrote:
>> I was thinking that there were a few useful applications for 
>> using metaprogramming could be used as
>>
>> int rng()
>> {
>>
>> }
>
> I think pressing the tab key just sent this message before I 
> was sure I even wanted to type it. Let's see if the tab key is 
> the verdict.... Okay the tab key selected the send element and 
> then I must have pressed enter. Let's try that...

Not really metaprogramming I suppose. I think I know how I made 
myself think that and explaining it is more than I can write.

I'm sure somebody is going to be curious to what I was going to 
write so I suppose I have to write it anyway. Will what I write 
be coherent? Probably not.

I want this. With sensible syntax.

int rng (int n)
dbg { // define what can be put into the value of the keyvalue 
store of the debug database
   int notSoRandomNumber;
}
body {
   dbg // Checks if the database is empty then if there is an 
entry for the callee of this method
   {
     // return a number determined outside of compile time and 
provided by the user
     return dbg.notSoRandomNumber;
   }
   else
   {
     // do things normally
     return (a random number 0 through n);
   }
}

Callees automatically pass on who they are. You can select 
callees using some method (ide, gdb like breakpoint list, ect.) 
and then add entries.
You would be doing a search for where line and file equal what 
you select.

usage of the above function

string[] choices = ["dead", "stone dead", "definitely deceased" 
"bleeding demised", "not pining", "passed on", "no more", "ceased 
to be", "expired and gone to meet his maker", "a stiff", "Bereft 
of life", "rests in peace", "ect.", "EX-PARROT"];
writeln(choices[rng(choices.length)]);

You could write this function and not have to change the code 
that calls it!

Another fun idea. dbg variables can be searched in the database.

for(dbg int i = 0; i < 5; i++)
{
   string[] choices = ["dead", "stone dead", "definitely deceased" 
"bleeding demised", "not pining", "passed on", "no more", "ceased 
to be", "expired and gone to meet his maker", "a stiff", "Bereft 
of life", "rests in peace", "ect.", "EX-PARROT"];
   writeln(choices[rng(choices.length)]);
}

You could decide to only interfer when i = 3 for example.

This idea may be stupid but that cursed tab and enter thing 
forced me to write this regardless of if it's any good.