Apply pattern matching to R1CS duplicate functions.

[dusk-network]

Apply pattern matching to R1CS duplicate functions.

[kevaundray]

I think the example we discussed over the call, was due to derive macros.

Would be interesting to see the code complexity if these were implemented.

[CPerezz]

As the functions like result() and pad() have variadic arguments depending if we are working with R1CS or not, the only way to optimize the code (macros are inline) and also reduce the duplicate code is to use mentioned macros. Since type matching is quite ugly to apply.

Another option (that will prioritize readability) will be to implement these functions passing the extra parameters (if we work with R1CS) with Options.

Something like:

pub fn constrain_result(
        &mut self,
        cs: Option<&mut dyn ConstraintSystem>,
    ) -> Result<Vec<T>, PermError> { 
        match cs {} // Check if we have a cs or we are not in the R1CS case.
        // Code....
}

[CPerezz]

This does not make sense anymore since the changes done in #23