Release Highlights

• First update changelog!
• Added MakeFiles and updated setup.cfgs to easily compile and build grammer from qasm3.g4
• Initial translator package with limited functionality.
• Currently supported definitions from ast: BranchingStatement, ClassicalAssignment, ClassicalDeclaration, ConstantDeclaration, ForInLoop, QuantumBarrier, QuantumGate, QuantumGateDefinition, QuantumMeasurementAssignment, QuantumPhase, QuantumReset, QubitDeclaration, Statement, Concatenation, Identifier, IndexIdentifier, RangeDefinition, Selection, Slice, Subscript, BinaryExpression, BooleanLiteral, Constant, DurationLiteral, Expression, FunctionCall, Identifier, IndexExpression, IntegerLiteral, RealLiteral, StringLiteral, UnaryExpression, Span.

Update notes

• Added MakeFile’s to source/openqasm and source/grammer to compile and build grammer from qasm3.g4
• Updated setup.cfgs with pylint and black support
• Update log
  

  1. source/openqasm/tests/build_ast.py - Test parser for validating statement numbers, OpenQASM version and ForLoop Listing for example adder.qasm in openqasm/examples

  2. source/openqasm/src/openqasm/translator/context.py - Stores a parseable context in a dict-like structure.
     • _OpenQASMIdentifier: Class to store necessary information about location of identifiers defined by type Span from ast w.r.t source. Keeps track of start and end of line following antlr convention.
     • class OpenQASMContext: Stores the necessary content to parse the OpenQASM 3.0 file
       • add_symbol = Adds an initialized symbol. Stores in _symbols dict
       • lookup = searches value in context dict _symbols
       • declare_symbol = Adds uninitialized symbol with None value to context dict _symbols
  3. source/openqasm/src/openqasm/translator/exceptions.py - Handles exceptions for the whole translator package. Also holds location info for each error occurred w.r.t source.
     Methods:
     • UnsupportedFeature = raises error and displays unsupported feature_name with a reason
     • UnsupportedExpressionType = raises an invalid expression_type_name error.
     • UndefinedSymbol = raises undeclared identifier error
     • UnkownConstant = raises undeclared constant identifier error
     • UninitializedSymbol = raises error for an uninitialized identifier which requires an initialization
     • MissingExpression = Raises error for a wrongly structured expression or missing expression
  4. source/openqasm/src/openqasm/translator/expressions.py - Computes Expression according to type. Main class = _ComputeExpressionNamespace
     Methods:
     • compute_BinaryExpression = Computes lhs and rhs w.r.t context grammar. Returns evaluated expression using default eval func
     • compute_UnaryExpression = Computes value of Unary expression with the operator w.r.t context grammar. Returns evaluated expression using default eval func
     • compute_Constant = Checks for constant values in supported list and returns the constant value corresponding to _CONSTANT_VALUES dict
     • compute_Identifier = Returns Identifier corresponding to the context stored in _symbol dict in context.py
     • compute_IntegerLiteral = Returns Integer Literal corresponding to the context stored in _symbol dict in context.py
     • compute_RealLiteral = Returns Real Literal corresponding to the context stored in _symbol dict in context.py
     • compute_BooleanLiteral = Returns Boolean literal corresponding to the context stored in _symbol dict in context.py
     • compute_StringLiteral = Returns Boolean literal corresponding to the context stored in _symbol dict in context.py
     • compute_DurationLiteral = Currently unsupported. Throws a UnsupportedExpressionType error.
     • compute_FunctionCall = Compute_expression for each of the passed list of arguments w.r.t context grammar and returns values of function name corresponding to the context stored in _symbol dict in context.py
     • compute_IndexExpression = Compute_expression for index value w.r.t context grammar and returns compute_expression for the expression part for the particular index passed.
     • compute_Expression = Computes generic expression; Stores method_name as a formatted string with prefix compute_(input_expression_type) and returns attribute of the method w.r.t. Context grammar passing the relevant expression and context. Throws UnsupportedExpressionType exception if expression not currently supported by context.
  5. source/openqasm/src/openqasm/translator/identifiers.py - Defines identifiers and processes the relevant type of identifier as per definition in ast.
     Methods:
     • get_identifier = takes in either an Identifier or IndexIdentifier from ast and returns attributes after passing it to the relevant method_name in the _IdentifierRetrieverNamespace
     • get_Subscript = computes the index and returns lookup value in context _symbols dict for that index.
     • get_Selection = computes list of input indexes and returns list of lookup symbols w.r.t context
     • get_Slice = computes the input range and returns list of range of objects returned after evaluating, start, end and step points from context definition
     • get_Concatenation = computes concatenated list of passed arrays w.r.t context. Checks if the returned identifier lookup is a list and casts it to a list if needed.

  6. source/openqasm/src/openqasm/translator/modifiers.py - Defines apply_modifier to apply appropriate modifier to quantum gate. Supports inv, pow and ctrl. .negctrl type also supported as of [2c5bc5]. Also compute_expression for number of ctrl and power as per context.

  7. source/openqasm/src/openqasm/translator/translator.py - Translator to convert OpenQASM 3.0 into a qiskit QuantumCircuit instance
     Methods:
     • translate = Translates given ast to a qiskit QuantumCircuit instance. Declares a QuantumCircuit and context object and passes on each ast statement to _process_Statement for further breaking it down and retrieves the resulting processed qiskit QuantumCircuit object and returns the same.
     • _process_statement = Extracts each statement type, name and formats function name as per its relevant function name to be passed on to for relevant processing. The relevant processing_function_name is passed on with statement, circuit and context as arguments. Also checks if the function name is a supported feature and returns an UnsupportedFeature exception
     • _supported_features = Returns list of supported AST type names
     • _process_QubitDeclaration = Process QubitDeclaration node in AST. Sets default size to 1 otherwise compute_expression as per context for quantum_register_size. Declares the register and adds it to the circuit as well as adds qubit.name and register to _symbol dict in context.
     • _process_ConstantDeclaration = Process ConstantDeclaration node in AST. Checks current statement node and either declares it as None if uninitialised or adds it to _symbol dict in context
     • _process_ClassicalDeclaration = Processes ClassicalDeclaration node in AST if supported. Initializes expression to none or adds it to _symbol dict.
     • _process_QuantumReset = Processes QuantumReset node and applies reset operation to the given qubit in context
     • _process_QuantumGate = Processes QuantumGate node in AST. Appends relevant gate operation to the qubit in context. Applies the relevant gate modifier from modifiers.py if applicable
     • _process_QuantumGateDefinition = Processes custom parameterized gates as specified in QuantumGateDefinition from ast. Returns an equivalent custom gate to the input definition.
     • _process_QuantumPhase = Processes a custom phase input to a gate upto a global phase. Appends the equivalent phased_gate to the circuit object declared in translate method