DOP-C Programming Guide

Sorting Rows

For operations on a large portion of the table’s data, it can be useful to first sort the rows.
This sorting can either be done according to a single field, or according to the values in the entire row.

Sorting by a Field

To sort by a field, we use the Field<T>::sort method. This method accepts a function as an argument. This function should take two references to the type T and return a bool. This return value should be true if the references are in the correct order, and false otherwise. You can make your own function, but dopc.hpp contains the SortAscending<T> function as a convenient example.

dopc::Table table; 
dopc::Field<int> a(&table); 
/*
do whatever
*/
a.sort(dopc::SortAscending<int>);

When sorting this way, other fields are also affected.

Sorting by the Entire Row

Some sorting rules depend on multiple fields. So we can make a function which takes two indices and returns a `bool``.

bool rule(size_t a, size_t b)
{
    /*
    encode the rule here
    */
}

void foo()
{
    Data::table.indexSort(rule);
}

The rule can of course use the indices whichever way it chooses. It is expected however, that these indices will be used to refer to table elements.