OpenQASM Missing Language Features

[orpuente-MS]

The following features are missing in our OpenQASM implementation, and we plan to implement them in the near future:

• Index into sized types.
• Array concatenation
• Built-in functions (sin, cos, etc.)
  • Foundation and mod implementation Add support for builtin functions #2508
  • Implementation of builtin functions Implement builtin functions #2521
  • pow edge case: pow builtin collides with pow gate modifier.
• sizeof and durationof calls.
• Alias declarations for qubits.
• Index sets arr[{2, 6, 8}].
• Array references (passing arrays as readonly parameters).
• box statement.
• Extern functions.
• Importing files other than "stdgates.inc". Consolidate OpenQASM project loading and include handling #2512
• Ranges with open start or end: [:1:5], [0:1:]. Support omitted start and stop in ranges #2472

These features require work in the Q# compiler and we plan to implement them at some point, but not in the near future:

• break keyword.
• continue keyword.
• Array references (passing arrays as mutable parameters).
• alias declarations for non-qubits
• register concatenation

These features are not planned for full compilation support:

• Hardware qubit ids.
• Duration type value, this includes supplying durations on gate and box instructions.
• Stretch type values.
• Calibration statements.
• Calibration grammar statements.
• Defcal statements.
• Delay statements.