OpenQASM Active Issues

[idavis]

• [ ] Implicit casting is too lenient compiling more programs that technically allowed
• [x] Type checking for register concatenation is too strict (incorrect).
• [x] Better user guidance on failure to capture non-const symbols in OpenQASM #2653
• [x] OPENQASM statements don't validate version correctly. Likely need to update parser to return Err(None) instead of Ok(None) #2650
• [x] Specifying a gate name immediately followed by a ; does not cause an error and the gate call is ignored (h; for example). #2625
• [x] For common symbol resolution errors that would be solved by including "stdgates.inc", create an error variant with help text letting the user know. #2625
• [x] Mutable array refs can't be used in indexed assignment expressions #2616
• [x] Slicing endianess for classical values isn't handled correctly #2600
• [x] annotation parsing should properly use namespaced idents. #2594
• [x] pragma parsing should properly use namespaced idents. #2571
• [x] When parsing arrays as reference using the array[T, #dim = n] syntax, we should use a different AST struct instead of storing the n as the length of the first dimension. #2557
• [x] "timing literals are not supported" error has incorrect span. #2559
• [x] Trying to include an external file has its error location incorrectly set to the top of the file #2512
• [x] When an include isn't found, the error span is incorrect. #2512
• [x] Function types in errors are not pretty printed. Like when when trying to cast a def to an int. #2508
• [x] gate is not highlighted as a keyword. #2459
• [x] For copilot instructions, see if we can tell copilot to give a preamble when creating openqasm files to help avoid common issues such as undefined gates. #2462

[blakejohnson]

It looks like you don't currently support bit-level indexing into types like int, uint, angle, etc. The relevant part of the OpenQASM spec is here: https://openqasm.com/language/types.html#classical-value-bit-slicing

[idavis]

@blakejohnson I'll create another tracking issue for missing language features. We were only tracking bugs here, but we need to show what language parts we haven't implemented.