Tuples

[EmilyBourne]

The current implementation of tuples is not satisfactory for 3 main reasons:

1. Tuples as arguments/results are not handled
2. Tuples are stored in TupleVariable classes which make them incompatible with classes
3. Tuples are handled as a special case, but lots of things needed for tuples will also be needed for other containers (sets, maps, lists).

In order to fix the 2nd and 3rd problems, tuples should be treated using class notation. This should be straightforward for HomogeneousTupleVariables but is non-trivial for InhomogeneousTupleVariables.

The tasks are therefore:

• Use class notation for tuples
  • Deprecate HomogeneousTupleVariable #1582
  • Deprecate InhomogeneousTupleVariable #1583
• Add support for tuples as arguments
  • Add support for tuples as arguments #1519
  • Allow homogeneous tuples as read-only function arguments #738
• Add support for tuples as results
  • Returning a homogeneous tuple calculated as output from a function doesn't work #1321
  • Cannot return a tuple #337
• Add documentation

Related issues:

• COVERAGE : tuples in _visit_Assign Function #1392
• inhomogeneous tuples breaks pyccel #1182
• Add support for the function tuple #1571