OpenQASM Custom Gate instruction causes transpiler error in some devices. #157
Description
Currently, no quantum backend fully implements all features specified in OpenQASM 3.
In fact, our own quantum devices and simulators (namely Qulacs) do not support the gate statement, and submitting programs that contain a gate statement results in a backend error.
I think we need to design how to represent, within the application, which QASM features each device supports, and based on that, implement a mechanism that enables or disables certain Composer features accordingly.
Our immediate concern is that the feature which introduces gate statements into QASM — namely, the grouping feature — is currently exposed to users without any restrictions. As noted above, this allows users to unknowingly submit programs that result in backend errors. As a quick, stopgap measure to prevent this, we would like to make the grouping button’s visibility configurable via an environment variable.