Improve the classical declarations and assignments

[TheGupta2012]

Feature Description

Continuation of #85.

Details

Some tasks were left in the issue -

1. Array Initialization using ArrayLiteral. Eg-

// 1-D 
array[int[32], 3] my_arr = {1, 2, 3};

This should be able to handle arbitrary dimensions eg. -

// N-D should also be supported
array[int[32], 2, 3] my_arr = {{1, 2, 3}, {4, 5, 6};

To be updated -

• qbraid-qir/qbraid_qir/qasm3/visitor.py

  Line 841 in 975744c

  # TODO: account for array initializations and update the init_value

2. Type casting during assignment and expression evaluation: Users should be able to cast types allowed in openqasm3. Reference - type casting in openqasm

To be updated -

• Some logic change for -

  qbraid-qir/qbraid_qir/qasm3/visitor.py

  Line 946 in 975744c

  self._validate_variable_assignment_value(self._get_scope()[var_name], var_value)

  to handle "castable" values. Eg. An int[32] can be cast to float[32] but not vice versa.

3. Validating constant value expressions to only use const variables: Constant expression can not contain variables, it should be validated that the init expression only uses literals or other const variables. Reference - constants in openqasm.

To be updated -

• It would be nice to have a flag in self._evaluate_expression for evaluating the constant initial expressions. This could be set to True and the values coming in should then be validated whether they are constant or not.
• Another approach could be creating a new constant expression evaluator but may result in redundancy.

4. Add complex type support (optional)

5. Add angle type support (optional)