Re: extend pgbench expressions with functions

Hello Michaël,

> + * Recursive evaluation of int or double expressions
> + *
> + * Note that currently only integer variables are available, with values
> + * stored as text.
> This comment is incorrect, we only care about integers in this patch.

Indeed!

> Taking patch 1 as a completely independent thing, there is no need to 
> introduce PgBenchValueType yet. Similar remark for setIntValue and 
> coerceToInt. They are useful afterwards when introducing double types to 
> be able to handle double input parameters for the gaussian and other 
> functions.

Yes. This is exactly the pain I'm trying to avoid, creating a different 
implementation for the first patch, which is just overriden when the 
second part is applied...

So I'm trying to compromise, having a several part patch *but* having the 
infrastructure ready for the second patch which adds the double type.

Note that the first patch without the second is a loss of time for 
everyone, as the nearly only useful functions are the randoms, which 
require a double argument, so it does not make sense to apply the first 
one if the second one is not to be applied, I think.

> [...]
> (INT64_MIN / -1) should error.
> (INT64_MIN % -1) should result in 0.
> This is missing the division handling.

Oops, indeed I totally messed up when merging the handling of / and %:-(

I have found another issue in the (a) patch: the internal scripts were 
using the future random function which do not yet exist, as they are in 
patch (b).

Here is a three part v30, which still includes the infrastructure for 
future types in the a patch, see my argumentation above.

-- 
Fabien.